Seminar #69 from Online Seminars for Municipal Arborists – July / August 2016
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Extending the Forestry Budget
By Len Phillips
Most people consider municipal funding for tree management and planting as a pure luxury in the budget and it should be the first place to cut when times are tough. This attitude is common because people see trees only as necessary for their beauty and have nothing to do with public health. People remember the disruption trees cause to the utilities and private property during storms. They also dislike the cleanup required after storms and the leaves that come down every autumn.
Because of these negative issues, arborists have tried to reverse this concern from many different approaches. Most recently we have been classifying trees as infrastructure and a solution to global warming. To some degree, this helps gain acceptance from public officials, but the municipal tree budgets are still the first-to-cut.
So what is the municipal arborist to do? Where should the priority be? Do you cut preventive maintenance, emergency response, tree planting, staff, equipment, contracted services??? Or should the focus be on increasing the efficiency of the tree management program, making the department too valuable to cut, and raising funds from other sources. This article will focus on extending the forestry budget.
Fortunately, the economy has begun to bounce back from the “Great Recession”. Now is a good time to seek more funding. Not only do people have a bit more money in their pockets, but with climate change on everyone's mind, people are looking for “green” solutions.
Listed below are some ideas for getting more tree management funds within the limited municipal budget. These ideas have proven to be successful enough to include in this discussion.
Tree Fund Donations
The first step the municipal arborist must do is talk to the city budget director or treasurer to see if monetary gifts can be accepted for use by the tree department to purchase and maintain trees within the city. The gifts should be tax deductible and specifically for planting or maintaining trees on municipal property. With that set up, you can become very creative in your search for additional tree care dollars.
Cost Sharing Programs
Start locally, in your own city and the various city budgets. Look at the line items and ask other city departments for funds to maintain trees on municipal properties such as the schools, the parks, the conservation properties. One of my favorites was to have the highway department pay for landscaping and maintaining their traffic islands. In a similar fashion, I liked to use parking meter receipts to cover the cost for tree and landscape enhancement and maintenance of the municipal parking lots. If you have private land owning organizations in the city, go to them with the same request.
You might have to ask for additional employees to do this additional work, but the transfer of funds should be more than enough to cover your costs. By making the tree department important to other departments in the good times, it becomes too important to cut in the bad times. Also be creative with your employee assignments. I recall having one employee who became too ill to climb, but by assigning him to line clearing from the bucket truck, he continued to use his skills working under the direction of the municipal electric company and was grateful he could keep working. The list goes on. Happy employees are productive employees.
Many state and philanthropic organizations have funds available that can be used for the care of trees. Sometimes these funds require a match with the funds in your budget or funds in your tree gift fund. Local citizens are sometimes willing to make donations for a specific planting project and will match city funds. Also, don’t be afraid to ask local garden clubs as well as corporate and civic organizations to contribute to your tree gift fund especially if you can tie a tree management effort into one of the organization’s projects.
Alternative Funding Sources
Sometimes there are other city, state, or federal programs as well as private corporations who have set aside funds that are not directly related to tree planting, but may require landscaping as part of a development project. Be aware of these projects and be prepared to request that funds be available for planting or maintaining street trees as a requirement for approval of the project.
Funds are often available from the US Forest Service that might be used for inventories, canopy mapping, planting, and sometimes even maintenance. Some cities are getting tree management funds from the EPA and their Urban Waters, Environmental Justice, and 319 grants. The DOT has funding available in the TIGER grant program. Also encourage your city to go after Complete Streets Program funds. While you are focused on federal grants, plan to spend a day at your computer studying grants.com for more ideas.
State and regional funds are also available for tree planting matching funds. Contact your state Urban Forestry Coordinator for more information. Also make contact with special districts such as water districts, sewer districts, regional zoos or arboretums, shopping centers, colleges, and other large commercial or industrial complexes for financial support of beautification programs near their facilities that exist or are proposed.
Local groups such as garden clubs and other civic organizations, as well as private foundations, often have funds for local beautification projects. Be involved with these groups to participate in their beautification efforts so municipal trees become part of their projects. Often simply mentioning the existence of the tree gift fund will encourage private or corporation donations. Take advantage of your status as a public, non-profit agency, having professional staff and administrative support systems, when applying for private grants. For more information about foundations, visit Foundation Center.
By working with the planning board and other municipal departments, you can have a local code approved that will require that every tree removed for a development project be replaced elsewhere in the city. Also ask that the public trees growing adjacent to the project be pruned once or maintained in perpetuity by the developer. In a similar way, the city should require all local utility companies to replace all trees removed for line maintenance, near where the trees were removed. Alternative to this would be a cash donation from the utility to the municipal tree gift fund. In this case, let the utility know that only low-growing trees that would be planted under the overhead lines would be purchased, and these would not require any trimming past the first structural pruning.
Many people also like to have a tree planted in memory of a loved one who was involved with the city or a civic organization. Sometimes the donor is willing to have an engraved stone or a bronze plaque placed at the base of the tree. Other times the donation should be noted in a gift remembrance book that is kept on public display. Publicizing this gift or dedicating the tree as part of the annual Arbor Day ceremony is a great way to encourage additional donations. Try to always obtain the Arbor Day tree as a gift.
Once you have completed your tree inventory and prepared a street tree master plan, develop a 10-year environmental improvement plan to plant “x” number of trees every year. By making this a justifiable capital project in the master plan, you should be able to convince the city leaders to approve and fund this long term capital improvement project.
Stormwater utility fees are now being assessed to all property owners to deal with stormwater management. The investment in planting and maintaining trees is an acceptable use of these funds.
Revenue sharing is still alive in many cities. This program usually helps the departments that have been underfunded.
Reimbursements
When an auto accident or large fire in the city has damaged public shade trees, you should seek insurance claims for reimbursement of the tree’s property value or to pay for the tree's repair and maintenance and have a contractor come in to do the job instead of using your own tree crews. If the tree is a total loss, add the funds to the tree gift fund for tree replacements during the next planting season and use the money to purchase more trees than are budgeted.
City employees should be reimbursed for the time they spend reviewing applications and inspecting city issued permits. This reimbursement should be included as a part of the permit fee.
Resident Options
By considering any of the following options, not only is there a chance of freeing up funds for additional tree purchases, but you can also build positive public relations with your city’s residents.
Tips for Getting a Lower Cost
By taking advantage of quantity discounts at the nursery when purchasing trees, you may have to reduce the number of varieties you want, but the lower price allows the purchase of more trees. If you are coming up short in the numbers, try to combine your order with other departments and other cities to earn the quantity discounts. If you have a good relationship with the nurseries you often do business with, you might be able to take advantage of nursery overstock and accept lower quality trees as gifts or at a very low cost. These extra trees are very suitable for parks and conservation properties.
Try new varieties to learn about better and sometimes less expensive trees. Every once in a while a tree comes along that does very well in your city and you are able to purchase them at better prices than what you usually spend. Sometimes you find a new tree that turned out to not be popular, but the nursery grew more that it could sell. You may get them at a lower than normal cost.
Nurseries are also willing to offer discounts if they know they can sell a particular tree when it reaches the right size. So, if your city and local laws allow, write a long-term growers contract with a nursery to provide your list of trees in 3 or 4 years. Even if a bid is necessary, have 3 nurseries bid on the contract and select the one that grows the best trees. If you are required to bid for all trees, consider this option, using the 'Quality Nursery Tree' specification found on our Specification Page.
One major cost saving tip is to plant bare root trees, which are half the cost of B&B trees. Bare root trees are easy for the trained volunteer to plant as well. Contractors will charge half to one-third the cost of planting B&B if they are planting bare root.
Planting smaller trees are less expensive than large trees, not only in the purchase price, but the planting price as well. Plus the smaller trees will recover from the transplant shock much faster than the larger tree. Many times I have seen a 1-1/2 inch (4 cm) diameter tree, out-grow a 4 inch (10 cm) tree in 4 years.
If watering is included in the tree planting cost, use water bags to reduce watering time and the cost after planting. The water bags not only provide water at the desirable slow drip, they fill up in a few minutes. Keep track of how many trees a person can water in a day and then see how much time is saved with the water bags in use. Reuse the water bags for several years. Depending on your budget system, if the watering is paid out of the tree planting fund, then the money saved is available to plant additional trees.
Most cities require all purchases to be made by bidding. However there is usually a quote system that applies to small purchases. If each tree is considered a separate item, you may be able to obtain quotes for each tree separately and each size of tree quoted by the planting contractor. Quoted prices are usually lower than bid prices. For more information on this program see “A Tree Planting Program That Works”.
Long Term Ideas
One long term idea requires the use of a city-owned vacant lot to plant a diverse forest of trees using low cost whips from a wholesale nursery. This idea will require a minimal level of municipal staff or volunteers until the trees reach a size that will survive transplanting onto the city streets. When transplanting the trees over a series of years, be sure to leave enough growing on the vacant lot to create a long-term forest filled with a diversity of species.
Here are a couple of ideas that will require a new policy. The first idea will require residents wanting a public tree removed to provide funds to replace the tree elsewhere in the city. The second idea is similar but pertains to trees on private property. This would be a law or regulation that requires a permit to remove trees on private property. A fee system for the permit would provide some funds for additional tree planting somewhere else or the law could require tree replacement one for one on another property.
Finally, many cities have chosen to sell their urban wood, wood chips, and composted leaves generated by the tree department. The revenue from the sales can be placed in the tree planting fund to be used for purchasing additional trees the following year.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Len Phillips
Most people consider municipal funding for tree management and planting as a pure luxury in the budget and it should be the first place to cut when times are tough. This attitude is common because people see trees only as necessary for their beauty and have nothing to do with public health. People remember the disruption trees cause to the utilities and private property during storms. They also dislike the cleanup required after storms and the leaves that come down every autumn.
Because of these negative issues, arborists have tried to reverse this concern from many different approaches. Most recently we have been classifying trees as infrastructure and a solution to global warming. To some degree, this helps gain acceptance from public officials, but the municipal tree budgets are still the first-to-cut.
So what is the municipal arborist to do? Where should the priority be? Do you cut preventive maintenance, emergency response, tree planting, staff, equipment, contracted services??? Or should the focus be on increasing the efficiency of the tree management program, making the department too valuable to cut, and raising funds from other sources. This article will focus on extending the forestry budget.
Fortunately, the economy has begun to bounce back from the “Great Recession”. Now is a good time to seek more funding. Not only do people have a bit more money in their pockets, but with climate change on everyone's mind, people are looking for “green” solutions.
Listed below are some ideas for getting more tree management funds within the limited municipal budget. These ideas have proven to be successful enough to include in this discussion.
Tree Fund Donations
The first step the municipal arborist must do is talk to the city budget director or treasurer to see if monetary gifts can be accepted for use by the tree department to purchase and maintain trees within the city. The gifts should be tax deductible and specifically for planting or maintaining trees on municipal property. With that set up, you can become very creative in your search for additional tree care dollars.
Cost Sharing Programs
Start locally, in your own city and the various city budgets. Look at the line items and ask other city departments for funds to maintain trees on municipal properties such as the schools, the parks, the conservation properties. One of my favorites was to have the highway department pay for landscaping and maintaining their traffic islands. In a similar fashion, I liked to use parking meter receipts to cover the cost for tree and landscape enhancement and maintenance of the municipal parking lots. If you have private land owning organizations in the city, go to them with the same request.
You might have to ask for additional employees to do this additional work, but the transfer of funds should be more than enough to cover your costs. By making the tree department important to other departments in the good times, it becomes too important to cut in the bad times. Also be creative with your employee assignments. I recall having one employee who became too ill to climb, but by assigning him to line clearing from the bucket truck, he continued to use his skills working under the direction of the municipal electric company and was grateful he could keep working. The list goes on. Happy employees are productive employees.
Many state and philanthropic organizations have funds available that can be used for the care of trees. Sometimes these funds require a match with the funds in your budget or funds in your tree gift fund. Local citizens are sometimes willing to make donations for a specific planting project and will match city funds. Also, don’t be afraid to ask local garden clubs as well as corporate and civic organizations to contribute to your tree gift fund especially if you can tie a tree management effort into one of the organization’s projects.
Alternative Funding Sources
Sometimes there are other city, state, or federal programs as well as private corporations who have set aside funds that are not directly related to tree planting, but may require landscaping as part of a development project. Be aware of these projects and be prepared to request that funds be available for planting or maintaining street trees as a requirement for approval of the project.
Funds are often available from the US Forest Service that might be used for inventories, canopy mapping, planting, and sometimes even maintenance. Some cities are getting tree management funds from the EPA and their Urban Waters, Environmental Justice, and 319 grants. The DOT has funding available in the TIGER grant program. Also encourage your city to go after Complete Streets Program funds. While you are focused on federal grants, plan to spend a day at your computer studying grants.com for more ideas.
State and regional funds are also available for tree planting matching funds. Contact your state Urban Forestry Coordinator for more information. Also make contact with special districts such as water districts, sewer districts, regional zoos or arboretums, shopping centers, colleges, and other large commercial or industrial complexes for financial support of beautification programs near their facilities that exist or are proposed.
Local groups such as garden clubs and other civic organizations, as well as private foundations, often have funds for local beautification projects. Be involved with these groups to participate in their beautification efforts so municipal trees become part of their projects. Often simply mentioning the existence of the tree gift fund will encourage private or corporation donations. Take advantage of your status as a public, non-profit agency, having professional staff and administrative support systems, when applying for private grants. For more information about foundations, visit Foundation Center.
By working with the planning board and other municipal departments, you can have a local code approved that will require that every tree removed for a development project be replaced elsewhere in the city. Also ask that the public trees growing adjacent to the project be pruned once or maintained in perpetuity by the developer. In a similar way, the city should require all local utility companies to replace all trees removed for line maintenance, near where the trees were removed. Alternative to this would be a cash donation from the utility to the municipal tree gift fund. In this case, let the utility know that only low-growing trees that would be planted under the overhead lines would be purchased, and these would not require any trimming past the first structural pruning.
Many people also like to have a tree planted in memory of a loved one who was involved with the city or a civic organization. Sometimes the donor is willing to have an engraved stone or a bronze plaque placed at the base of the tree. Other times the donation should be noted in a gift remembrance book that is kept on public display. Publicizing this gift or dedicating the tree as part of the annual Arbor Day ceremony is a great way to encourage additional donations. Try to always obtain the Arbor Day tree as a gift.
Once you have completed your tree inventory and prepared a street tree master plan, develop a 10-year environmental improvement plan to plant “x” number of trees every year. By making this a justifiable capital project in the master plan, you should be able to convince the city leaders to approve and fund this long term capital improvement project.
Stormwater utility fees are now being assessed to all property owners to deal with stormwater management. The investment in planting and maintaining trees is an acceptable use of these funds.
Revenue sharing is still alive in many cities. This program usually helps the departments that have been underfunded.
Reimbursements
When an auto accident or large fire in the city has damaged public shade trees, you should seek insurance claims for reimbursement of the tree’s property value or to pay for the tree's repair and maintenance and have a contractor come in to do the job instead of using your own tree crews. If the tree is a total loss, add the funds to the tree gift fund for tree replacements during the next planting season and use the money to purchase more trees than are budgeted.
City employees should be reimbursed for the time they spend reviewing applications and inspecting city issued permits. This reimbursement should be included as a part of the permit fee.
Resident Options
By considering any of the following options, not only is there a chance of freeing up funds for additional tree purchases, but you can also build positive public relations with your city’s residents.
- Some cities will allow residents to volunteer to plant trees and perform maintenance duties, so municipal labor funds can be used to purchase additional trees. Some of these volunteer programs have become very popular. In every case, the volunteer must attend a Saturday morning training session, so they know how to properly plant a tree. This is especially important if the volunteers are planting “light weight and easy to plant” bare root trees.
- The cities that offer pruning programs for volunteers require a whole day training session, including hands-on pruning. These pruning programs do not allow any tree climbing. The focus is on structural pruning of young trees that were planted within the past 5 years. The intent is to be sure the trees have a proper structure for a long term of vigorous growth that requires very little future maintenance.
Tips for Getting a Lower Cost
By taking advantage of quantity discounts at the nursery when purchasing trees, you may have to reduce the number of varieties you want, but the lower price allows the purchase of more trees. If you are coming up short in the numbers, try to combine your order with other departments and other cities to earn the quantity discounts. If you have a good relationship with the nurseries you often do business with, you might be able to take advantage of nursery overstock and accept lower quality trees as gifts or at a very low cost. These extra trees are very suitable for parks and conservation properties.
Try new varieties to learn about better and sometimes less expensive trees. Every once in a while a tree comes along that does very well in your city and you are able to purchase them at better prices than what you usually spend. Sometimes you find a new tree that turned out to not be popular, but the nursery grew more that it could sell. You may get them at a lower than normal cost.
Nurseries are also willing to offer discounts if they know they can sell a particular tree when it reaches the right size. So, if your city and local laws allow, write a long-term growers contract with a nursery to provide your list of trees in 3 or 4 years. Even if a bid is necessary, have 3 nurseries bid on the contract and select the one that grows the best trees. If you are required to bid for all trees, consider this option, using the 'Quality Nursery Tree' specification found on our Specification Page.
One major cost saving tip is to plant bare root trees, which are half the cost of B&B trees. Bare root trees are easy for the trained volunteer to plant as well. Contractors will charge half to one-third the cost of planting B&B if they are planting bare root.
Planting smaller trees are less expensive than large trees, not only in the purchase price, but the planting price as well. Plus the smaller trees will recover from the transplant shock much faster than the larger tree. Many times I have seen a 1-1/2 inch (4 cm) diameter tree, out-grow a 4 inch (10 cm) tree in 4 years.
If watering is included in the tree planting cost, use water bags to reduce watering time and the cost after planting. The water bags not only provide water at the desirable slow drip, they fill up in a few minutes. Keep track of how many trees a person can water in a day and then see how much time is saved with the water bags in use. Reuse the water bags for several years. Depending on your budget system, if the watering is paid out of the tree planting fund, then the money saved is available to plant additional trees.
Most cities require all purchases to be made by bidding. However there is usually a quote system that applies to small purchases. If each tree is considered a separate item, you may be able to obtain quotes for each tree separately and each size of tree quoted by the planting contractor. Quoted prices are usually lower than bid prices. For more information on this program see “A Tree Planting Program That Works”.
Long Term Ideas
One long term idea requires the use of a city-owned vacant lot to plant a diverse forest of trees using low cost whips from a wholesale nursery. This idea will require a minimal level of municipal staff or volunteers until the trees reach a size that will survive transplanting onto the city streets. When transplanting the trees over a series of years, be sure to leave enough growing on the vacant lot to create a long-term forest filled with a diversity of species.
Here are a couple of ideas that will require a new policy. The first idea will require residents wanting a public tree removed to provide funds to replace the tree elsewhere in the city. The second idea is similar but pertains to trees on private property. This would be a law or regulation that requires a permit to remove trees on private property. A fee system for the permit would provide some funds for additional tree planting somewhere else or the law could require tree replacement one for one on another property.
Finally, many cities have chosen to sell their urban wood, wood chips, and composted leaves generated by the tree department. The revenue from the sales can be placed in the tree planting fund to be used for purchasing additional trees the following year.
Sources
- Special thanks to the members of LinkedIn’s Urban Forestry Discussion Group for providing many of these ideas.
- Gulick, Jennifer, "Budgeting and Funding 101", Public Works, March 2016.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Planting Trees in the City
By Naomi Zürcher
Historically, almost all of our urban trees originated in a forest somewhere in the world. In order to understand the underpinnings of our urban trees and the extent of their resilience, we first have to understand the where and what they came from:
First, we built roads inside the Forest, creating new edges, introducing sunlight to the Forest floor where it never was before. Then we cleared the land and it evolved through cultivating it, into urbanizing it. Now that most of us are living in cities, we’ve decided we want to put those same Forest trees back into our urban landscapes – not the way they were before, not the way they evolved to exist, but according to our needs and our designs.
The Urban Spatial Resource: Where to Plant Trees in the City
The fact that our urban trees, given their genetics and evolution, have found ways to deal with everything our urban life and the new, very dynamic associate – us – inflict on them, should inspire us to support their resilience and endurance. By observing Forest trees’ growth strategies and applying what we learn from those lessons, we could use our limited urban spatial resources more thoughtfully and, when combined with a much more appropriate species selection criteria, offer our urban trees a much greater accommodation of their critical needs:
What we cannot set aside is this - if we plant our public trees into hardscape coffins in an inadequate, inaccessible soil volume and we expect those large canopy trees to thrive and provide all those wonderful and beneficial Ecosystem Services we are dependent on, we are greatly diminishing the potential of our urban trees and we are undermining our own well-being.
Growing Trees Right
We know what it takes to kill a tree, here is what we must do to grow a tree.
It behooves us – scientists, researches, academics, and practitioners – to afford the powers-that-be an enhanced understanding of what City life could be if we, in the midst of all our urban UN-naturalness, recognize that when you plant a tree, you begin an entire Universe. So why not plant our Urban Forest “tree-positive”.
Naomi Zürcher is an independent Consulting Arborist and Urban Forester as Arbor Aegis and is involved with the current COST Action GreenInUrbs project.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Naomi Zürcher
Historically, almost all of our urban trees originated in a forest somewhere in the world. In order to understand the underpinnings of our urban trees and the extent of their resilience, we first have to understand the where and what they came from:
- Forests
are a process of Succession, of Evolution;
- Forests
do not happen in a day, a week, a year. They occur over millennia,
beginning with the specific soils they populate.
- Forests
are a sophisticated community of trees and all their associates –
other flora, fauna and, most importantly, soil containing a healthy
soil microbial community, while providing access to the nutrients, macro
and micro, that the Forest community associates depend on.
- Forests
evolve in direct relationship to their environment – temperature
range, the soil’s pH and the availability of light and water.
These elements will dictate which tree species will grow and where
within the Forest system – edge or interior – they will be
found.
- Although
a Forest may consist of many different species of trees, space above
ground is shared in competition, while space below ground is shared
in community.
- Forest
soil is always covered by plants, leaf litter or other organic
Forest debris – a
constant renewing and recycling of organic nutrient resources.
- Trees
grow with their root crown – their buttress roots – above the
soil line; all parts of the tree that are covered with bark are
always above the soil line.
First, we built roads inside the Forest, creating new edges, introducing sunlight to the Forest floor where it never was before. Then we cleared the land and it evolved through cultivating it, into urbanizing it. Now that most of us are living in cities, we’ve decided we want to put those same Forest trees back into our urban landscapes – not the way they were before, not the way they evolved to exist, but according to our needs and our designs.
The Urban Spatial Resource: Where to Plant Trees in the City
The fact that our urban trees, given their genetics and evolution, have found ways to deal with everything our urban life and the new, very dynamic associate – us – inflict on them, should inspire us to support their resilience and endurance. By observing Forest trees’ growth strategies and applying what we learn from those lessons, we could use our limited urban spatial resources more thoughtfully and, when combined with a much more appropriate species selection criteria, offer our urban trees a much greater accommodation of their critical needs:
- It
all begins with the soil. Soil attributes are a pre-cursor to the
successful
growing of urban trees. We have neglected the critical aspect of
this component of a successful planting. Species should not only be
matched to the soils we expect them to grow in – structure, pH,
texture (from a “preferred” perspective as opposed to a “will
tolerate” one), the soil we install must be complete, with a
minimum of an organic as well as an A and B horizon.
- Tree
health is largely dependent on tree roots’ ability to access an
adequate supply of air as well as moisture and water soluble
nutrients - exchanges that take place in that landscape underground.
The ability of trees’ roots to develop the mycorrhizosphere that
supports efficient community-based nutrient uptake is an essential
aspect of long term tree health. Soils that do not have an adequate
microbial community are unable to support the mycorrhizosphere.
- A
great deal of research has been conducted on what constitutes an
adequate, accessible soil volume, although we have not yet found the
“silver bullet” for the most extreme spatial resource – the
curbside tree. There are several strategies now in play that assist
in the expansion of soil volume in a non-porous, paved environment,
e.g. CU soil or Silva Cells. Each solution has its preferred usage,
requires additional funding and is not advantageous in all curbside
planting situations given that, within a sealed environment, we do
not have research showing the organic content adequacy of tree root
exudate. CU soil should never be used inside curbside tree planting
areas, aka, tree pits, and it works best if there is an open
landscape on the opposite side of the pavement. Soil cells are an
excellent strategy for areas such a parking lots but when used
curbside, the presence of adjacent utility infrastructure can often
disturb the installation sometime in the future and negate some of
the root development gains from the increase in accessible soil
volume.
- The
above ground competition that limits the extent of branch expansion
is greatly reduced in an urban setting, resulting in a much larger
crown. A thorough understanding of this phenotypic development is
essential if we are to site the right tree in the right place,
reducing the need for constant excess pruning or the unnecessary and
premature removal of the tree.
- When
we plant urban trees in parkland or open landscapes where there is a
predominance of lawn, e.g. backyard gardens, we are doing our trees
a disservice if we continue to favor the needs of lawn as opposed to
the needs of the tree. Lawn is a heavy feeder and thus a major
competitor for essential moisture and nutrients thus directly
reducing tree root development and impacting tree growth. In
addition, most of our urban trees prefer a pH in the acid to neutral
range. Grass prefers an alkaline environment. Lawns and their upkeep
reinforce this pH disparity, increasing the ability of trees’
roots to access locked up nutrients.
- When
we design and build public infrastructure projects that fall within
an existing treed landscape, the normal strategy is to remove all
the trees that are perceived to be in the way of the project. It is
essential that the design aspect of these projects be informed with
tree-friendly design, enabling building WITH trees. There are many
strategies that can be employed to protect and preserve important
trees that fall within a project’s footprint – auguring,
jacking, air spade access to do accurate root pruning, adequate
fencing, ground surface protection mats. While a viable new tree
planting program is essential, retention of existing trees is a
critical component of a healthy urban forest.
What we cannot set aside is this - if we plant our public trees into hardscape coffins in an inadequate, inaccessible soil volume and we expect those large canopy trees to thrive and provide all those wonderful and beneficial Ecosystem Services we are dependent on, we are greatly diminishing the potential of our urban trees and we are undermining our own well-being.
Growing Trees Right
We know what it takes to kill a tree, here is what we must do to grow a tree.
It behooves us – scientists, researches, academics, and practitioners – to afford the powers-that-be an enhanced understanding of what City life could be if we, in the midst of all our urban UN-naturalness, recognize that when you plant a tree, you begin an entire Universe. So why not plant our Urban Forest “tree-positive”.
Naomi Zürcher is an independent Consulting Arborist and Urban Forester as Arbor Aegis and is involved with the current COST Action GreenInUrbs project.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tree of the Seminar #69
By Len Phillips
Sassafras is widespread throughout eastern U.S. This native is ideal for naturalistic landscaping. Both tree form and leaf shape are variable and interesting. A thicket of sassafras brings a “woodsy” feel to the landscape.
Trade Name: Sassafras
Botanical Name: Sassafras albidum
Family: Lauraceae
Parentage: Native
Height: 30' - 60'
Spread: 25' - 40'
Form: Pyramidal, irregular
Flower: Yellow, slightly fragrant, beautiful when observed up close, 1” – 2” long
Fruit: Drupe is 1/2” long, dark blue on red stem, handsome up close
Foliage: Smooth leaves have 1, 2, or 3 lobes, on yellowish-green petiole
Spring Color: Pale yellowish-green flowers, stems, and young leaves
Summer Foliage: Medium green
Autumn Foliage: Yellow to orange to scarlet to purple, outstanding for fall color
Winter Color: Handsome bark and tree form in winter
Bark: Dark reddish-brown, ridged and furrowed with corky ridges
Habitat: Eastern half of the U.S.
Culture: Moist, acidic soil
Hardiness Zone: 4 – 9
Growth Rate: Full size in less than 30 years
Pest Resistance: Free of major pest problems
Storm Resistance: Good
Salt Resistance: Good
Planting: Transplant B&B or container, difficult due to the tap root and few lateral roots
Pruning: Keep sucker growth removed if single stem tree is desired
Propagating: Seeds or root cuttings in winter
Design Uses: Excellent for naturalizing a street or residential landscape
Companions: Best in sassafras thicket
Site Requirements: Full sun to partial shade
Other Comments: Roots are used to make tea and oil
Photo
Sources
This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6 and information provided by J. Frank Schmidt & Son.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Len Phillips
Sassafras is widespread throughout eastern U.S. This native is ideal for naturalistic landscaping. Both tree form and leaf shape are variable and interesting. A thicket of sassafras brings a “woodsy” feel to the landscape.
Trade Name: Sassafras
Botanical Name: Sassafras albidum
Family: Lauraceae
Parentage: Native
Height: 30' - 60'
Spread: 25' - 40'
Form: Pyramidal, irregular
Flower: Yellow, slightly fragrant, beautiful when observed up close, 1” – 2” long
Fruit: Drupe is 1/2” long, dark blue on red stem, handsome up close
Foliage: Smooth leaves have 1, 2, or 3 lobes, on yellowish-green petiole
Spring Color: Pale yellowish-green flowers, stems, and young leaves
Summer Foliage: Medium green
Autumn Foliage: Yellow to orange to scarlet to purple, outstanding for fall color
Winter Color: Handsome bark and tree form in winter
Bark: Dark reddish-brown, ridged and furrowed with corky ridges
Habitat: Eastern half of the U.S.
Culture: Moist, acidic soil
Hardiness Zone: 4 – 9
Growth Rate: Full size in less than 30 years
Pest Resistance: Free of major pest problems
Storm Resistance: Good
Salt Resistance: Good
Planting: Transplant B&B or container, difficult due to the tap root and few lateral roots
Pruning: Keep sucker growth removed if single stem tree is desired
Propagating: Seeds or root cuttings in winter
Design Uses: Excellent for naturalizing a street or residential landscape
Companions: Best in sassafras thicket
Site Requirements: Full sun to partial shade
Other Comments: Roots are used to make tea and oil
Photo
Sources
This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6 and information provided by J. Frank Schmidt & Son.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tree Planting Soils under Pavement
Edited by Len Phillips
Trees that are growing in areas surrounded by pavement are often expected to grow in very poor quality urban soils, which shorten their useful life expectancy. This article describes a comparison of the growth of trees in five different soil treatments that have been tried under a pavement.
Two species of trees were selected to grow in each of the five different soils. The trees were Snowgoose Cherry (Prunus serrulata) and Bosque Lacebark Elm (Ulmus parvifolia). These species were selected because they are medium-sized trees at maturity and their roots grow aggressively. The trees were planted in each of the following different soils according to the detailed descriptions below.
1. Stone/Soil Mixture
Researchers at Cornell University experimented with and developed a stone and soil mix, consisting of 1 to 1½ in (2.5 to 3½ cm) diameter stone, sandy clay loam soil, and a small amount of hydrogel sprayed on the stone to glue the soil to the stone during mixing. Cornell's research suggests that this mixture, known as “CU Soil” is more beneficial for urban tree growth than standard compacted urban soil. Since the CU Soil is not available near the experiment site, the Stone/Soil Mixture is very similar, but not exactly CU-Soil. It is comprised of 80% stone (by weight) and 20% soil. The soil was placed in the 10 x10 feet (3 × 3 m) planting pit in lifts. The lifts were 8 in (20 cm) deep and were compacted with an impact compactor to 95% Proctor. See Photo
2. Expanded Slate
Expanded Slate is a porous expanded slate rock that is created by heating slate to over 1,000° F. It can hold water and nutrients and carry the load of concrete and vehicles. In addition, it can be installed and compacted more easily than the Stone/Soil Mixture. The Expanded Slate was installed in 12 in. (30 cm) lifts and compacted with a vibratory plate compactor according to the manufacturer’s specifications. This option was the fastest and simplest treatment to install. It required only pouring the stone and using a vibratory compactor in fairly large lifts. See Photo
3. Expanded Slate/Soil Mixture
Expanded Slate and Stone/Soil mixtures are both capable of meeting engineering and the load bearing requirements in urban areas by forming a stone matrix under the pavement. The soil between the stones is not compacted, leaving room for air exchange, holding water, and permitting root growth. This research showed that the Expanded Slate/Soil Mixture encourages roots to penetrate deeper into the ground rather than growing upward and causing pavement failures. This mixture is comprised of 80% Expanded Slate – ¾ to 1 in (1.5 to 2.5 cm) in diameter mixed with 20% sandy clay loam. The Expanded Slate was wetted before mixing with soil. Lifts were 12 in (30 cm) thick and compacted with a vibratory plate compactor according to the manufacturer’s specifications.
4. Compacted Soil
A sandy clay loam was installed in 8 inch (20 cm) lifts and compacted with an impact compactor to 95% Proctor. No amendments were added to this treatment. See Photo
5. Rehabilitated Soil
The existing soil at this site was rehabilitated using a backhoe excavator. This construction technique allowed the use of a loose, root friendly soil under the pavement. A suspended pavement was installed over the rehabilitated soil. The pavement may be either precast concrete lowered onto footers or concrete poured in place. Although the soils in the first three options contain approximately 20% soil by volume, which may affect water and nutrient availability, the suspended pavement can have nearly 95% of the soil volume in non-compacted soil. This option was second in speed and ease of installation. However, there was the additional step of drilling and pouring concrete footer pilings, which added to the time and cost of this treatment.
See Photo
Materials and Methods
The research was overseen by Dr. Tom Smiley at the Bartlett Tree Research Laboratory in Charlotte, North Carolina beginning in the spring of 2004. Each of the plots were lined with a thick Biobarrier non-woven fabric that was trenched 2 ft (60 cm) deep to surround the 10 × 10 ft (3 × 3 m) plots. The fabric was intended to confine the root growth. One tree was planted in the center of each plot giving the tree approximately 190 cu ft (5½ cu m) of medium to grow in. Trees were set in the middle of each plot and soil, stone, or mix was added and compacted as required in lifts around the trees.
As a result of the different construction techniques used in the non-compacted treatment, all of the non-compacted treatments were confined to a single row. All the other treatments were randomly assigned within a row, creating a randomized block design.
The final step was to install a concrete “urban plaza” or "sidewalk" over the plots leaving a 32 in (80 cm) round hole centered on each tree trunk. The concrete was 2 in (5 cm) thick near the center hole.
In the non-compacted soil plot, 6 in (15 cm) diameter footer holes were augured 24 in (60 cm) deep to act as footer pilings, and concrete was poured into the holes. A layer of gravel was applied to the soil surface before pouring the concrete slab.
In each treatment plot, two trees of the two different species were planted. Tree caliper was 2 in (5 cm) dbh when installed. Wire baskets and burlap were removed from the top of the root balls at planting.
Results
Fourteen months after planting, there were distinct differences in tree growth, color, root growth, and crown dieback.
Conclusion
The trees growing in the non-compacted soil suspended pavement treatment are visually healthier in appearance and provide more shade more quickly than any of the other treatments. When designing for planting in spaces that require a solid surface for vehicles and pedestrians, the option of using suspended pavement over non-compacted soil has not received much attention over the past few years. If suspended pavement is to be used, the pavement will need to be engineered to take expected loads without fracturing. This may require greater reinforcement and installation of footers than pavement installed over structural soil.
Source
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Trees that are growing in areas surrounded by pavement are often expected to grow in very poor quality urban soils, which shorten their useful life expectancy. This article describes a comparison of the growth of trees in five different soil treatments that have been tried under a pavement.
Two species of trees were selected to grow in each of the five different soils. The trees were Snowgoose Cherry (Prunus serrulata) and Bosque Lacebark Elm (Ulmus parvifolia). These species were selected because they are medium-sized trees at maturity and their roots grow aggressively. The trees were planted in each of the following different soils according to the detailed descriptions below.
1. Stone/Soil Mixture
Researchers at Cornell University experimented with and developed a stone and soil mix, consisting of 1 to 1½ in (2.5 to 3½ cm) diameter stone, sandy clay loam soil, and a small amount of hydrogel sprayed on the stone to glue the soil to the stone during mixing. Cornell's research suggests that this mixture, known as “CU Soil” is more beneficial for urban tree growth than standard compacted urban soil. Since the CU Soil is not available near the experiment site, the Stone/Soil Mixture is very similar, but not exactly CU-Soil. It is comprised of 80% stone (by weight) and 20% soil. The soil was placed in the 10 x10 feet (3 × 3 m) planting pit in lifts. The lifts were 8 in (20 cm) deep and were compacted with an impact compactor to 95% Proctor. See Photo
2. Expanded Slate
Expanded Slate is a porous expanded slate rock that is created by heating slate to over 1,000° F. It can hold water and nutrients and carry the load of concrete and vehicles. In addition, it can be installed and compacted more easily than the Stone/Soil Mixture. The Expanded Slate was installed in 12 in. (30 cm) lifts and compacted with a vibratory plate compactor according to the manufacturer’s specifications. This option was the fastest and simplest treatment to install. It required only pouring the stone and using a vibratory compactor in fairly large lifts. See Photo
3. Expanded Slate/Soil Mixture
Expanded Slate and Stone/Soil mixtures are both capable of meeting engineering and the load bearing requirements in urban areas by forming a stone matrix under the pavement. The soil between the stones is not compacted, leaving room for air exchange, holding water, and permitting root growth. This research showed that the Expanded Slate/Soil Mixture encourages roots to penetrate deeper into the ground rather than growing upward and causing pavement failures. This mixture is comprised of 80% Expanded Slate – ¾ to 1 in (1.5 to 2.5 cm) in diameter mixed with 20% sandy clay loam. The Expanded Slate was wetted before mixing with soil. Lifts were 12 in (30 cm) thick and compacted with a vibratory plate compactor according to the manufacturer’s specifications.
4. Compacted Soil
A sandy clay loam was installed in 8 inch (20 cm) lifts and compacted with an impact compactor to 95% Proctor. No amendments were added to this treatment. See Photo
5. Rehabilitated Soil
The existing soil at this site was rehabilitated using a backhoe excavator. This construction technique allowed the use of a loose, root friendly soil under the pavement. A suspended pavement was installed over the rehabilitated soil. The pavement may be either precast concrete lowered onto footers or concrete poured in place. Although the soils in the first three options contain approximately 20% soil by volume, which may affect water and nutrient availability, the suspended pavement can have nearly 95% of the soil volume in non-compacted soil. This option was second in speed and ease of installation. However, there was the additional step of drilling and pouring concrete footer pilings, which added to the time and cost of this treatment.
See Photo
Materials and Methods
The research was overseen by Dr. Tom Smiley at the Bartlett Tree Research Laboratory in Charlotte, North Carolina beginning in the spring of 2004. Each of the plots were lined with a thick Biobarrier non-woven fabric that was trenched 2 ft (60 cm) deep to surround the 10 × 10 ft (3 × 3 m) plots. The fabric was intended to confine the root growth. One tree was planted in the center of each plot giving the tree approximately 190 cu ft (5½ cu m) of medium to grow in. Trees were set in the middle of each plot and soil, stone, or mix was added and compacted as required in lifts around the trees.
As a result of the different construction techniques used in the non-compacted treatment, all of the non-compacted treatments were confined to a single row. All the other treatments were randomly assigned within a row, creating a randomized block design.
The final step was to install a concrete “urban plaza” or "sidewalk" over the plots leaving a 32 in (80 cm) round hole centered on each tree trunk. The concrete was 2 in (5 cm) thick near the center hole.
In the non-compacted soil plot, 6 in (15 cm) diameter footer holes were augured 24 in (60 cm) deep to act as footer pilings, and concrete was poured into the holes. A layer of gravel was applied to the soil surface before pouring the concrete slab.
In each treatment plot, two trees of the two different species were planted. Tree caliper was 2 in (5 cm) dbh when installed. Wire baskets and burlap were removed from the top of the root balls at planting.
Results
Fourteen months after planting, there were distinct differences in tree growth, color, root growth, and crown dieback.
- The trees in the non-compacted/suspended pavement treatment ranked the highest in trunk diameter growth, twig growth rates, foliar color, and root length.
- The second best treatment in terms of tree quality was the Stone/Soil Mix treatment.
- Expanded Slate/soil and rehabilitated soil treatments were overall slightly worse than the Stone/Soil Mix treatment.
- There was significantly more dieback in the Expanded Slate treatment and rehabilitated treatment than the other treatments.
- Trees in the Expanded Slate and Expanded Slate/soil treatments exhibited a severe chlorosis within a month after planting. Foliar nutrient analysis found deficiencies in manganese and iron induced by the high pH of the Expanded Slate. The high pH factor of this product has since been corrected by the manufacturer.
- The Expanded Slate treatment was the easiest to install, However, it did not provide a favorable environment for tree growth.
- Mixing and compacting the Stone/Soil Mix was the most time-consuming portion of all these tree planting projects.
Conclusion
The trees growing in the non-compacted soil suspended pavement treatment are visually healthier in appearance and provide more shade more quickly than any of the other treatments. When designing for planting in spaces that require a solid surface for vehicles and pedestrians, the option of using suspended pavement over non-compacted soil has not received much attention over the past few years. If suspended pavement is to be used, the pavement will need to be engineered to take expected loads without fracturing. This may require greater reinforcement and installation of footers than pavement installed over structural soil.
Source
- Thomas Smiley, Lisa Calfee, Bruce R. Fraedrich, and Emma J. Smiley. “Structural and Non-compacted Soils for Trees”, Arboriculture & Urban Forestry, July 2006.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Anthracnose
Edited by Len Phillips
Anthracnose is a group of diseases that result in a wide range of symptoms including sunken lesions on leaves, stems, flowers, and fruits. It can also cause leaf blotches or distortion, defoliation, shoot blight, twig cankers, and dieback on many different deciduous and evergreen trees and shrubs. Anthracnose is most prevalent and destructive in early spring when cool, moist weather conditions favor the disease development.
Diseases
Often called leaf, shoot, or twig blight, tree anthracnose results from infection by fungi including Apiognomonia errabunda, A. veneta, Colletotrichum gloeosporioides, Discula destructiva, D. fraxinea, the Glomerella species, the Gnomonia species, some Marssonina species, and Stegophora ulmea, depending on the tree attacked.
Symptoms
Foliar symptoms of anthracnose vary considerably among host species, weather, and the time of year the infection occurs. On Sycamore, White Oak and Maple, large irregular tan, brown, black or tar-like spots appear on infected leaves of hosts. The lesions (dead areas) develop usually along leaf veins. On ash, black oak, dogwood, and walnut, discrete curricular or angular lesions occur on leaves. Several consecutive years of defoliation will severely weaken the dogwoods, predisposing them to invasion by insect borers and secondary diseases causing organisms such as canker and root decay fungi.
Often the first symptoms of Discula destructiva anthracnose on Dogwoods are spots on lower leaves and flower bracts. Spots are tan to brown and may have purple rings around them. Leaf tissue will also be killed along the veins. Those leaves, which succumb to infection during the summer, will persist after normal leaf drop. The infection will also spread from the leaves to the twig resulting in cankers and twig dieback. Epicormic branches (water sprouts) are more susceptible to the fungus. The resulting canker can girdle and kill the branch.
On Sycamore, White Oak, and Maple (Photo), the buds and succulent new shoots may be killed as a result of anthracnose. Lesions may also develop on flowers and fruit of some hosts. Lesions on the foliage often coalesce, resulting in distortion, blight, and defoliation. Generally, mature leaves are resistant to infection.
Blight and defoliation usually occur in early spring when leaves are small and succulent. If leaves are very young when infected, they can become curled and distorted with only a portion of each leaf dying. Crowns of severely diseased trees appear thin and scrubby. Often, the foliage is tufted on ends of branches, while the center of the tree is defoliated. Trees defoliated by anthracnose usually produce a second set of leaves in late spring or summer. Heavily infected leaves fall prematurely throughout the growing season, and sometimes trees become completely defoliated. Regrowth from lateral buds can give branches a gnarled or crooked appearance.
If defoliation, branch dieback, or cankering doesn’t occur every year, dogwood anthracnose won’t seriously harm plants. The disease usually starts on lower leaves and progresses into twigs and branches. Infected trees are severely weakened so that secondary canker and root rot diseases infect and kill the tree. Infection by Discula usually occurs during cool rainy periods in the spring. Dogwood anthracnose is found from Massachusetts to Georgia and also the Pacific region of Canada and the Pacific Northwest U.S.
Life Cycle
Anthracnose pathogens overwinter in twig cankers within specialized structures on infected twigs, diseased, or dead fallen leaves. Coinciding with bud-break in the spring, the fungi produce numerous microscopic spores that spread by wind and splashing rain or sprinkler water. Under cool, moist conditions, spores germinate and infect susceptible plant tissue to begin their destructive activity.
Shortly after lesions develop, spores are produced on the diseased plant tissue. These "summer spores" are disseminated to healthy tissue where they cause new infections. As long as moist weather conditions prevail, summer spores are produced from lesions on diseased plant parts. These spores are responsible for infections that occur in late spring and summer.
On some tree species, anthracnose fungi invade twigs from infected leaves. The pathogen may continue to grow in the twigs during the autumn after the leaves are cast, and in the spring prior to bud-break. Subsequently, infected twigs and buds may be killed during the dormant season.
Control
Cultural Practices: Vigorous trees are able to withstand disease infection much better than weak trees. To keep trees vigorous they should be mulched, watered, fertilized, and pruned. Mulch should extend to the drip line at a depth of 2-4 inches (5-10 cm). Irrigation should consist of a soaker hose, drip, or micro-sprinkler system – not a sprinkler that soaks the leaves. Fertilizers containing high levels of nitrogen improve tree vitality and reduce the spread of the disease.
Sanitation practices, which eliminate sources of the overwintering fungi, will provide some degree of control of anthracnose. Diseased leaves should be collected and destroyed in the fall, and diseased twigs and branches should be pruned out and destroyed to whatever degree possible.
Pruning during winter will allow optimum light and air penetrations through the crown, which will inhibit disease development by allowing more rapid drying of plant tissue following rains. Spacing the plants far enough apart to maximize air circulation and increase sunlight will also facilitate faster drying of leaf surfaces when trees are fully grown. Pruning out highly susceptible epicormic branches will reduce cankers on major stems and branches. Overstory trees may also need to be pruned or thinned to improve drying conditions on the understory trees.
Periodic fertilization will maintain tree vigor and help offset the deleterious effects of any premature defoliation from anthracnose.
Resistant Varieties: Avoid planting highly susceptible species including oaks (Quercus) especially white oaks, maples (Acer), all varieties of the native flowering dogwood (Cornus florida and C. nuttallii), ash (Fraxinus), American sycamore (Platanus occidentalis), and the London plane tree (P. acerifolia or P. hybrida). When planting London plane decide whether anthracnose or powdery mildew resistance is more beneficial based on prevailing environmental conditions at the site and the planned pruning method. The reason for this decision is because, the Bloodgood London plane tree cultivar is resistant to anthracnose but not to powdery mildew. On the other hand, the Yarwood cultivar of London plane is susceptible to anthracnose and resistant to powdery mildew.
Chemical Control: Properly timed fungicide applications will help control anthracnose. Fungicides are applied at periodic intervals during the spring in order to protect developing plant tissue from infection. Once infection occurs, however, chemical sprays are ineffective in preventing further disease development. The effectiveness of chemical control is dependent on spring weather conditions, the proximity of untreated trees to sprayed trees, and the thoroughness of the sanitation program. Generally, more frequent applications of fungicides are necessary to obtain a high degree of control during cool, moist springs. With sycamores the option exists to inject fungicide into the tree that will provide multiple years of protection. Consult the local authorities for the proper fungicide, rates and timings for control of anthracnose on specific tree species.
Fungicides will reduce new infections but will not stop the existing disease. Treatments should be applied three or four times at 14-day intervals starting at bud-break. Additional treatments may be required at monthly intervals during the summer if wet weather persists.
Additionally in early spring, an application, either by basal spray or soil drench, of a phosphoric material, such as Agri-fos® Systemic Fungicide, will aid in the control of this disease. Use this material in the early spring to prevent or lessen the severity of anthracnose and also control powdery mildew. Follow label instructions when preparing this material for application.
Sources
Editor's Note: No endorsement by mention of product names is assumed by Online Seminars. The use of trade or product names is for the information and convenience of the readers. Such mention does not constitute an evaluation, recommendation, endorsement, or approval of any product to the exclusion of others.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Anthracnose is a group of diseases that result in a wide range of symptoms including sunken lesions on leaves, stems, flowers, and fruits. It can also cause leaf blotches or distortion, defoliation, shoot blight, twig cankers, and dieback on many different deciduous and evergreen trees and shrubs. Anthracnose is most prevalent and destructive in early spring when cool, moist weather conditions favor the disease development.
Diseases
Often called leaf, shoot, or twig blight, tree anthracnose results from infection by fungi including Apiognomonia errabunda, A. veneta, Colletotrichum gloeosporioides, Discula destructiva, D. fraxinea, the Glomerella species, the Gnomonia species, some Marssonina species, and Stegophora ulmea, depending on the tree attacked.
Symptoms
Foliar symptoms of anthracnose vary considerably among host species, weather, and the time of year the infection occurs. On Sycamore, White Oak and Maple, large irregular tan, brown, black or tar-like spots appear on infected leaves of hosts. The lesions (dead areas) develop usually along leaf veins. On ash, black oak, dogwood, and walnut, discrete curricular or angular lesions occur on leaves. Several consecutive years of defoliation will severely weaken the dogwoods, predisposing them to invasion by insect borers and secondary diseases causing organisms such as canker and root decay fungi.
Often the first symptoms of Discula destructiva anthracnose on Dogwoods are spots on lower leaves and flower bracts. Spots are tan to brown and may have purple rings around them. Leaf tissue will also be killed along the veins. Those leaves, which succumb to infection during the summer, will persist after normal leaf drop. The infection will also spread from the leaves to the twig resulting in cankers and twig dieback. Epicormic branches (water sprouts) are more susceptible to the fungus. The resulting canker can girdle and kill the branch.
On Sycamore, White Oak, and Maple (Photo), the buds and succulent new shoots may be killed as a result of anthracnose. Lesions may also develop on flowers and fruit of some hosts. Lesions on the foliage often coalesce, resulting in distortion, blight, and defoliation. Generally, mature leaves are resistant to infection.
Blight and defoliation usually occur in early spring when leaves are small and succulent. If leaves are very young when infected, they can become curled and distorted with only a portion of each leaf dying. Crowns of severely diseased trees appear thin and scrubby. Often, the foliage is tufted on ends of branches, while the center of the tree is defoliated. Trees defoliated by anthracnose usually produce a second set of leaves in late spring or summer. Heavily infected leaves fall prematurely throughout the growing season, and sometimes trees become completely defoliated. Regrowth from lateral buds can give branches a gnarled or crooked appearance.
If defoliation, branch dieback, or cankering doesn’t occur every year, dogwood anthracnose won’t seriously harm plants. The disease usually starts on lower leaves and progresses into twigs and branches. Infected trees are severely weakened so that secondary canker and root rot diseases infect and kill the tree. Infection by Discula usually occurs during cool rainy periods in the spring. Dogwood anthracnose is found from Massachusetts to Georgia and also the Pacific region of Canada and the Pacific Northwest U.S.
Life Cycle
Anthracnose pathogens overwinter in twig cankers within specialized structures on infected twigs, diseased, or dead fallen leaves. Coinciding with bud-break in the spring, the fungi produce numerous microscopic spores that spread by wind and splashing rain or sprinkler water. Under cool, moist conditions, spores germinate and infect susceptible plant tissue to begin their destructive activity.
Shortly after lesions develop, spores are produced on the diseased plant tissue. These "summer spores" are disseminated to healthy tissue where they cause new infections. As long as moist weather conditions prevail, summer spores are produced from lesions on diseased plant parts. These spores are responsible for infections that occur in late spring and summer.
On some tree species, anthracnose fungi invade twigs from infected leaves. The pathogen may continue to grow in the twigs during the autumn after the leaves are cast, and in the spring prior to bud-break. Subsequently, infected twigs and buds may be killed during the dormant season.
Control
Cultural Practices: Vigorous trees are able to withstand disease infection much better than weak trees. To keep trees vigorous they should be mulched, watered, fertilized, and pruned. Mulch should extend to the drip line at a depth of 2-4 inches (5-10 cm). Irrigation should consist of a soaker hose, drip, or micro-sprinkler system – not a sprinkler that soaks the leaves. Fertilizers containing high levels of nitrogen improve tree vitality and reduce the spread of the disease.
Sanitation practices, which eliminate sources of the overwintering fungi, will provide some degree of control of anthracnose. Diseased leaves should be collected and destroyed in the fall, and diseased twigs and branches should be pruned out and destroyed to whatever degree possible.
Pruning during winter will allow optimum light and air penetrations through the crown, which will inhibit disease development by allowing more rapid drying of plant tissue following rains. Spacing the plants far enough apart to maximize air circulation and increase sunlight will also facilitate faster drying of leaf surfaces when trees are fully grown. Pruning out highly susceptible epicormic branches will reduce cankers on major stems and branches. Overstory trees may also need to be pruned or thinned to improve drying conditions on the understory trees.
Periodic fertilization will maintain tree vigor and help offset the deleterious effects of any premature defoliation from anthracnose.
Resistant Varieties: Avoid planting highly susceptible species including oaks (Quercus) especially white oaks, maples (Acer), all varieties of the native flowering dogwood (Cornus florida and C. nuttallii), ash (Fraxinus), American sycamore (Platanus occidentalis), and the London plane tree (P. acerifolia or P. hybrida). When planting London plane decide whether anthracnose or powdery mildew resistance is more beneficial based on prevailing environmental conditions at the site and the planned pruning method. The reason for this decision is because, the Bloodgood London plane tree cultivar is resistant to anthracnose but not to powdery mildew. On the other hand, the Yarwood cultivar of London plane is susceptible to anthracnose and resistant to powdery mildew.
Chemical Control: Properly timed fungicide applications will help control anthracnose. Fungicides are applied at periodic intervals during the spring in order to protect developing plant tissue from infection. Once infection occurs, however, chemical sprays are ineffective in preventing further disease development. The effectiveness of chemical control is dependent on spring weather conditions, the proximity of untreated trees to sprayed trees, and the thoroughness of the sanitation program. Generally, more frequent applications of fungicides are necessary to obtain a high degree of control during cool, moist springs. With sycamores the option exists to inject fungicide into the tree that will provide multiple years of protection. Consult the local authorities for the proper fungicide, rates and timings for control of anthracnose on specific tree species.
Fungicides will reduce new infections but will not stop the existing disease. Treatments should be applied three or four times at 14-day intervals starting at bud-break. Additional treatments may be required at monthly intervals during the summer if wet weather persists.
Additionally in early spring, an application, either by basal spray or soil drench, of a phosphoric material, such as Agri-fos® Systemic Fungicide, will aid in the control of this disease. Use this material in the early spring to prevent or lessen the severity of anthracnose and also control powdery mildew. Follow label instructions when preparing this material for application.
Sources
- Farrar, James, “How to Manage Anthracnose”, University of California Integrated Pest Management, 2016.
- Fraedrich, Bruce R. Ph. D., “Anthracnose of Shade Trees”, Technical Report, Bartlett Tree Research Laboratory.
- Fraedrich, Bruce R. Ph. D., “Dogwood Anthracnose”, Technical Report, Bartlett Tree Research Lab.
Editor's Note: No endorsement by mention of product names is assumed by Online Seminars. The use of trade or product names is for the information and convenience of the readers. Such mention does not constitute an evaluation, recommendation, endorsement, or approval of any product to the exclusion of others.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Mulching Trees
Edited by Len Phillips
The use of organic mulches in the landscape is intended to duplicate the leaves in deciduous forests where they are annually deposited on the forest floor. Leaves act to insulate the soil in winter and are the mechanism by which carbon and mineral nutrients are recycled into the soil. The decaying leaves provide food for all the creatures that live in the forest soil.
Mulch Types
Mulch can be anything that will facilitate the survival of microorganisms in the soil, conserve soil moisture, reduce weed growth in competition with the tree, and mulch can be any locally available product that will simulate the conditions of the forest floor. Though there is no single best mulch, except leaves from the forest trees, organic mulches are better for the tree and the ecology of soil. Mulch from coniferous plants are best for placement over the roots of conifers and hardwood mulch is considered the best for around hardwood trees.
There are two basic categories of mulch – organic and inorganic.
Organic Mulch
Organic mulches include leaves and shredded leaves, wood chips, shredded or chunk pine bark, pine needles, lumber yard wood waste, composted yard waste, buckwheat hulls, nut shells, ground corn cobs, cocoa shells, composted animal manure, and garden composts.
Benefits of Organic Mulch
Organic mulches provide many benefits to the soil as well as to tree growth. Organic mulch:
Green mulch, such as chopped weeds and grass clippings, will provide many of the benefits mentioned above. It will compete with the tree for water and nutrients until the mulch breaks down and returns the nutrients to the soil at a lower level where the plant roots actually need them and in a form the roots can absorb.
Inorganic Mulch
Inorganic mulch does not become part of the soil and break down over time. Inorganic mulches include volcanic or lava rock, crushed coral, pea gravel, crushed brick, and river rocks. They will not improve the microorganism activity in the soil.
Benefits of Inorganic Mulch
Since inorganic mulches, such as rubber or rock, add nothing to the soil, they are less desirable than organic mulches. Inorganic mulches have applications in locations where organic mulches might blow away or the soil is not suitable for growing plants. The major benefit is that inorganic mulch has a much longer life-span.
Mulch Color
Mulch color has become very popular in recent years. Colored mulch is made from processed wood chips. There are two types of coloring systems, one wet and the other dry. Both systems add the color during the final grinding. The dry process adds less water to the wood chips than the wet process. The wet system is much easier to use and provides a higher quality product. The dry system allows the chips to dry faster so there is less chance of mold and there is less spillage of dye from the chipper. See Photo
No longer does red mulch indicate it is pine bark. It could be twice processed deciduous wood chips with iron dye added to give it the red color. Black mulch does not indicate the mulch is processed compost. It could be reground wood chips with carbon dye added to provide the black color. Brown mulch could be the natural color of freshly processed natural wood and bark or it could be the carbon and iron dyes mixed together to make brown. Color will greatly enhance the value of the mulch. Not only will the sale of the product be much greater than the natural wood chip, lower quality mulch can also be colored and made more sale-able.
Mulch Depth
Coarse-textured mulches such as wood chips, should be placed 2 – 3 inches (5 – 8 cm) deep annually, to allow good oxygen diffusion into the soil. Finer-textured mulch such as shredded bark or buckwheat hulls, should only be a 1 – 2 inches (2½ – 5 cm) layer. On poorly drained or wet soils, mulch depths should not exceed 2 inches (5 cm), especially for shallow rooted plants and trees.
Renewing mulch layers periodically should be done with as much care as the first layer. A light raking of existing mulch may be all that is needed to break through the layers. One to two inches (2½ – 5 cm) of new mulch is usually sufficient. The additional mulch will replace the mulch layer at the soil surface which decomposed during the previous growing season.
Newly planted trees should have mulch in the saucers 3 – 4 inches (8 – 10 cm) deep to form a 3 – 6 foot (1 – 2 m) diameter circle around the tree. As the tree becomes larger, expand the mulch to a 10 – 12 foot (3 – 4 m) diameter ring.
Mulch applied in the early winter, before the snow, but after the frost will provide maximum protection to the soil microorganisms and tender plants. An application of 1 – 2 inches of mulch in early winter will also suppress early emergence of perennial weeds in the spring.
Excessive Mulch
Excessive use of piled mulch such as "volcanoes", which are cones of mulch creeping up the trunk of a tree, can induce fermentation, immobilize nutrients, increase the amount of moisture next to the trunk, cut off the oxygen supply, and kill the tree from stress. The application of excessive mulch is common where mulch is used decoratively around a tree. Tree roots, in an effort to find more oxygen, will often grow above the soil surface and into the mulch. This makes those roots and the tree, more susceptible to drought, temperature extremes, frost heaving, and bark abrasion, especially if using inorganic mulches. Trees that have been wounded on the stem are predisposed to stem canker pathogens if the mulch is covering the wound. Trees are also prone to form adventitious roots in excess mulch that develop into stem girdling roots. These effects of over-mulching are not immediately observed, so it may take a few years for the effects to be noticed and by then, it may be too late.
Current guidelines suggest keeping mulch from touching all tree and plant trunks and stems. As rule of thumb, keep mulch 3 to 5 inches (8 – 12 cm) away from young trees and 8 to 12 inches (20 – 30 cm) away from mature tree trunks. If mulch volcanoes are observed in the landscape, pull them down and away from the stems and spread them out over a larger area.
Problems with Mulch
Despite all the benefits that mulch supplies to trees, there are some major problems:
Acidic Mulch
"Sour" mulch can occur when mulch is piled very deep and this prevents an adequate air exchange. Without adequate oxygen, anaerobic microorganisms become active and cause the mulch to give off foul odors and produce extremely acidic pH levels. This mulch is highly toxic to plants. Avoid using it until it is properly composted and aerated.
Researchers have found that the continuous use of the same type of mulch does not change the soil's acidity level. So-called acidic mulches like pine bark may have a pH of 3.5 – 4.5 during the composting process, but when the composting is finished the pH is close to neutral.
Allelopathic toxins
Allelopathic toxins are compounds produced by plants that inhibit the growth of other plants. The classic example of allelopathy is found in the black walnut (Juglans nigra). It produces juglone and juglonic acid, which inhibit the growth of many plants and trees that could become competition for the walnut. Fresh wood chips from black walnut should not be used as mulch unless well composted. Other allelopathic mulches include uncomposted sawdust of redwood (Sequoia) and cedar (Cedrus) and the bark of spruce (Picea), larch (Larix), and Douglas fir (Pseudotsuga). Once the wood chips have decomposed, the toxins have lost their potency.
Source
This is an update from Archive #38
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
The use of organic mulches in the landscape is intended to duplicate the leaves in deciduous forests where they are annually deposited on the forest floor. Leaves act to insulate the soil in winter and are the mechanism by which carbon and mineral nutrients are recycled into the soil. The decaying leaves provide food for all the creatures that live in the forest soil.
Mulch Types
Mulch can be anything that will facilitate the survival of microorganisms in the soil, conserve soil moisture, reduce weed growth in competition with the tree, and mulch can be any locally available product that will simulate the conditions of the forest floor. Though there is no single best mulch, except leaves from the forest trees, organic mulches are better for the tree and the ecology of soil. Mulch from coniferous plants are best for placement over the roots of conifers and hardwood mulch is considered the best for around hardwood trees.
There are two basic categories of mulch – organic and inorganic.
Organic Mulch
Organic mulches include leaves and shredded leaves, wood chips, shredded or chunk pine bark, pine needles, lumber yard wood waste, composted yard waste, buckwheat hulls, nut shells, ground corn cobs, cocoa shells, composted animal manure, and garden composts.
Benefits of Organic Mulch
Organic mulches provide many benefits to the soil as well as to tree growth. Organic mulch:
- improves soil aeration and soil structure as it is broken down by soil microorganisms,
- moderates extremes in surface soil temperatures,
- will degrade pesticides and other contaminants,
- minimizes weed competition with tree roots,
- effectively reduces soil erosion,
- conserves soil moisture,
- will increase soil fertility,
- can help detoxify soils,
- restricts soil cracking,
- can reduce salt buildup,
- can reduce soil crusting,
- reduces soil compaction,
- can reduce maintenance costs,
- allows rainwater penetration into the soil,
- will protect the trunk from mowers and weed whips,
- will provide a habitat for active and diverse microorganism populations,
- will encourage trees to grow significantly faster and healthier than non-mulched trees.
Green mulch, such as chopped weeds and grass clippings, will provide many of the benefits mentioned above. It will compete with the tree for water and nutrients until the mulch breaks down and returns the nutrients to the soil at a lower level where the plant roots actually need them and in a form the roots can absorb.
Inorganic Mulch
Inorganic mulch does not become part of the soil and break down over time. Inorganic mulches include volcanic or lava rock, crushed coral, pea gravel, crushed brick, and river rocks. They will not improve the microorganism activity in the soil.
Benefits of Inorganic Mulch
Since inorganic mulches, such as rubber or rock, add nothing to the soil, they are less desirable than organic mulches. Inorganic mulches have applications in locations where organic mulches might blow away or the soil is not suitable for growing plants. The major benefit is that inorganic mulch has a much longer life-span.
Mulch Color
Mulch color has become very popular in recent years. Colored mulch is made from processed wood chips. There are two types of coloring systems, one wet and the other dry. Both systems add the color during the final grinding. The dry process adds less water to the wood chips than the wet process. The wet system is much easier to use and provides a higher quality product. The dry system allows the chips to dry faster so there is less chance of mold and there is less spillage of dye from the chipper. See Photo
No longer does red mulch indicate it is pine bark. It could be twice processed deciduous wood chips with iron dye added to give it the red color. Black mulch does not indicate the mulch is processed compost. It could be reground wood chips with carbon dye added to provide the black color. Brown mulch could be the natural color of freshly processed natural wood and bark or it could be the carbon and iron dyes mixed together to make brown. Color will greatly enhance the value of the mulch. Not only will the sale of the product be much greater than the natural wood chip, lower quality mulch can also be colored and made more sale-able.
Mulch Depth
Coarse-textured mulches such as wood chips, should be placed 2 – 3 inches (5 – 8 cm) deep annually, to allow good oxygen diffusion into the soil. Finer-textured mulch such as shredded bark or buckwheat hulls, should only be a 1 – 2 inches (2½ – 5 cm) layer. On poorly drained or wet soils, mulch depths should not exceed 2 inches (5 cm), especially for shallow rooted plants and trees.
Renewing mulch layers periodically should be done with as much care as the first layer. A light raking of existing mulch may be all that is needed to break through the layers. One to two inches (2½ – 5 cm) of new mulch is usually sufficient. The additional mulch will replace the mulch layer at the soil surface which decomposed during the previous growing season.
Newly planted trees should have mulch in the saucers 3 – 4 inches (8 – 10 cm) deep to form a 3 – 6 foot (1 – 2 m) diameter circle around the tree. As the tree becomes larger, expand the mulch to a 10 – 12 foot (3 – 4 m) diameter ring.
Mulch applied in the early winter, before the snow, but after the frost will provide maximum protection to the soil microorganisms and tender plants. An application of 1 – 2 inches of mulch in early winter will also suppress early emergence of perennial weeds in the spring.
Excessive Mulch
Excessive use of piled mulch such as "volcanoes", which are cones of mulch creeping up the trunk of a tree, can induce fermentation, immobilize nutrients, increase the amount of moisture next to the trunk, cut off the oxygen supply, and kill the tree from stress. The application of excessive mulch is common where mulch is used decoratively around a tree. Tree roots, in an effort to find more oxygen, will often grow above the soil surface and into the mulch. This makes those roots and the tree, more susceptible to drought, temperature extremes, frost heaving, and bark abrasion, especially if using inorganic mulches. Trees that have been wounded on the stem are predisposed to stem canker pathogens if the mulch is covering the wound. Trees are also prone to form adventitious roots in excess mulch that develop into stem girdling roots. These effects of over-mulching are not immediately observed, so it may take a few years for the effects to be noticed and by then, it may be too late.
Current guidelines suggest keeping mulch from touching all tree and plant trunks and stems. As rule of thumb, keep mulch 3 to 5 inches (8 – 12 cm) away from young trees and 8 to 12 inches (20 – 30 cm) away from mature tree trunks. If mulch volcanoes are observed in the landscape, pull them down and away from the stems and spread them out over a larger area.
Problems with Mulch
Despite all the benefits that mulch supplies to trees, there are some major problems:
- Freshly applied organic mulches and green mulch will tend to deplete soil nitrogen slightly and temporarily until the compost action is completed. At that point the nitrogen becomes available for the trees. Supplemental nitrogen fertilizer to speed up the decomposition process, if desired, does not work and should be avoided. The supplemental nitrogen is not in an available form and washes away.
- Mulch can provide habitat in which rodents can live and be protected from predators. The rodents will use the mulch for cover while feeding on the tree bark, thus being another reason to keep the mulch away from the tree trunk.
- Certain fungi grow in dry compacted mulches and prevent water from penetrating the soil.
- Geotextile fabrics used as mulch or used to prevent weed growth and is covered with mulch can lead to higher soil temperatures, shedding of rain and irrigation water, and are no longer recommended. In addition, the fabric threads become covered with microbes that prevent moisture from passing through the fabric, thereby making the fabric impervious.
- Black plastic and peat moss can cause the same problems as geotextile fabric in addition to creating a moisture and soil oxygen barrier that causes root surfacing. They are also no longer recommended.
Acidic Mulch
"Sour" mulch can occur when mulch is piled very deep and this prevents an adequate air exchange. Without adequate oxygen, anaerobic microorganisms become active and cause the mulch to give off foul odors and produce extremely acidic pH levels. This mulch is highly toxic to plants. Avoid using it until it is properly composted and aerated.
Researchers have found that the continuous use of the same type of mulch does not change the soil's acidity level. So-called acidic mulches like pine bark may have a pH of 3.5 – 4.5 during the composting process, but when the composting is finished the pH is close to neutral.
Allelopathic toxins
Allelopathic toxins are compounds produced by plants that inhibit the growth of other plants. The classic example of allelopathy is found in the black walnut (Juglans nigra). It produces juglone and juglonic acid, which inhibit the growth of many plants and trees that could become competition for the walnut. Fresh wood chips from black walnut should not be used as mulch unless well composted. Other allelopathic mulches include uncomposted sawdust of redwood (Sequoia) and cedar (Cedrus) and the bark of spruce (Picea), larch (Larix), and Douglas fir (Pseudotsuga). Once the wood chips have decomposed, the toxins have lost their potency.
Source
This is an update from Archive #38
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Cultivars of Black Locust
By Len Phillips
The following cultivars of Black Locust, (Robinia) offer unique forms, fast growth, and are well adapted to hot, dry climates. The description that follows provides a summary of similarities that all the cultivars possess.
Family: Fabaceae
Bloom Period: May into June
Flower: White clusters, fragrant, desired by honeybees
Fruit: Sparse black pods, smaller than the species
Culture: Tough and adaptable to poor soils from nitrogen fixing, likes full sun, fertile, moist soil
Growth Rate: Moderate to fast, full size in 10 years
Storm Resistance: Excellent due to very tough wood
Salt Resistance: Excellent
Pest Concerns: Borers, white flies, leaf miners, more vigorous trees have less trouble with pests
Planting: Easily transplanted BR or B&B, suitable for planting in CU-Structural Soil
Pruning: Late summer to fall due to spring bleeding
Propagating: Budded or grafted onto species under-stock, also own root from tissue culture
Design Uses: Does very well in urban conditions, city parks
Available from: Most large nurseries
Bessoniana Locust Robinia pseudoacacia ‘Bessoniana’ – Zone: 4 – 8; Height: 30'; Spread: 20'; Shape: Oval; Foliage: Medium green; Fall Color: Yellow; Flower: White, in clusters.
Bessoniana has a small, compact, well branched oval form, similar to Black Locust. The growth rate, form, and spineless character make it very compatible with people and urban settings. Photo
Globe Locust Robinia pseudoacacia ‘Inermis’ – Zone: 3 – 8; Height: 20'; Spread: 20'; Shape: Dense, compact, round; Foliage: Medium green; Fall Color: Yellowish
Globe locust has a formal shape and small size that make this tree useful in many landscape situations. It also has an advantage of being spineless. Photo
Purple Robe Locust Robinia pseudoacacia ‘Purple Robe’ – Zone: 3 – 8; Height: 50'; Spread: 32';
Shape: Ascending, outward arching branches, open; Foliage: Purple tinted new growth ages to bronze green; Fall Color: Yellowish; Flower: Dark purple; Fruit: Seedless pods
Purple Robe locust is a tough, fast growing tree and is well adapted to hot, dry climates. It is best suited for areas of the western US where it provides shade during hot dry summers. The spines are much smaller when compared to the species. This tree is much larger than the common black locust. Photo
Pyramidal Locust Robinia pseudoacacia ‘Pyramidalis’ – Zone: 3 – 8; Height: 40’; Spread: 15’;
Shape: Upright, columnar; Foliage: Medium green; Fall Color: Yellow; Flower: White, in clusters
The pyramidal locust is a tough tree that is very suitable for poor soils. The spineless feature and tight columnar shape make this tree ideal for narrow urban sites where choices are limited because of adverse growing conditions. Photo
Twisty Baby® Locust Robinia pseudoacacia ‘Lace Lady’ PP 9771 – Zone: 4 – 8; Height: 20'; Spread: 20';
Shape: Irregularly spreading, contorted; Foliage: Green, twisted; Fall Color: Yellow; Flower: White, in clusters
Twisty Baby is a dwarf, contorted tree of that has a very interesting appearance. The branches twist and turn at every node; even the foliage twists. Its irregular, artistic form is as interesting in winter as in summer. Yet from a distance, the tree has a very uniform appearance. Photo
Golden Locust Robinia pseudoacacia 'Frisia' – Zone: 4 – 8; Height: 30'; Spread: 30'; Shape: Irregularly spreading; Foliage: yellow and droopy; Fall Color: Yellow; Flower: White, in clusters
This large, fast-growing tree has droopy leaves that stay yellow from spring until frost. It also produces spiny shoots. The flowers are fragrant and white in late spring and early summer, on pendent racemes. The flowers are followed by smooth brown seed pods that are also interesting. Golden locust is one of the cultivars that is grown more for foliage than for its flowers and it does not flower as freely as the species. It does tend to send up suckers. Photo
Sources
This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6 and information provided by J. Frank Schmidt & Son nursery.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist,or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Len Phillips
The following cultivars of Black Locust, (Robinia) offer unique forms, fast growth, and are well adapted to hot, dry climates. The description that follows provides a summary of similarities that all the cultivars possess.
Family: Fabaceae
Bloom Period: May into June
Flower: White clusters, fragrant, desired by honeybees
Fruit: Sparse black pods, smaller than the species
Culture: Tough and adaptable to poor soils from nitrogen fixing, likes full sun, fertile, moist soil
Growth Rate: Moderate to fast, full size in 10 years
Storm Resistance: Excellent due to very tough wood
Salt Resistance: Excellent
Pest Concerns: Borers, white flies, leaf miners, more vigorous trees have less trouble with pests
Planting: Easily transplanted BR or B&B, suitable for planting in CU-Structural Soil
Pruning: Late summer to fall due to spring bleeding
Propagating: Budded or grafted onto species under-stock, also own root from tissue culture
Design Uses: Does very well in urban conditions, city parks
Available from: Most large nurseries
Bessoniana Locust Robinia pseudoacacia ‘Bessoniana’ – Zone: 4 – 8; Height: 30'; Spread: 20'; Shape: Oval; Foliage: Medium green; Fall Color: Yellow; Flower: White, in clusters.
Bessoniana has a small, compact, well branched oval form, similar to Black Locust. The growth rate, form, and spineless character make it very compatible with people and urban settings. Photo
Globe Locust Robinia pseudoacacia ‘Inermis’ – Zone: 3 – 8; Height: 20'; Spread: 20'; Shape: Dense, compact, round; Foliage: Medium green; Fall Color: Yellowish
Globe locust has a formal shape and small size that make this tree useful in many landscape situations. It also has an advantage of being spineless. Photo
Purple Robe Locust Robinia pseudoacacia ‘Purple Robe’ – Zone: 3 – 8; Height: 50'; Spread: 32';
Shape: Ascending, outward arching branches, open; Foliage: Purple tinted new growth ages to bronze green; Fall Color: Yellowish; Flower: Dark purple; Fruit: Seedless pods
Purple Robe locust is a tough, fast growing tree and is well adapted to hot, dry climates. It is best suited for areas of the western US where it provides shade during hot dry summers. The spines are much smaller when compared to the species. This tree is much larger than the common black locust. Photo
Pyramidal Locust Robinia pseudoacacia ‘Pyramidalis’ – Zone: 3 – 8; Height: 40’; Spread: 15’;
Shape: Upright, columnar; Foliage: Medium green; Fall Color: Yellow; Flower: White, in clusters
The pyramidal locust is a tough tree that is very suitable for poor soils. The spineless feature and tight columnar shape make this tree ideal for narrow urban sites where choices are limited because of adverse growing conditions. Photo
Twisty Baby® Locust Robinia pseudoacacia ‘Lace Lady’ PP 9771 – Zone: 4 – 8; Height: 20'; Spread: 20';
Shape: Irregularly spreading, contorted; Foliage: Green, twisted; Fall Color: Yellow; Flower: White, in clusters
Twisty Baby is a dwarf, contorted tree of that has a very interesting appearance. The branches twist and turn at every node; even the foliage twists. Its irregular, artistic form is as interesting in winter as in summer. Yet from a distance, the tree has a very uniform appearance. Photo
Golden Locust Robinia pseudoacacia 'Frisia' – Zone: 4 – 8; Height: 30'; Spread: 30'; Shape: Irregularly spreading; Foliage: yellow and droopy; Fall Color: Yellow; Flower: White, in clusters
This large, fast-growing tree has droopy leaves that stay yellow from spring until frost. It also produces spiny shoots. The flowers are fragrant and white in late spring and early summer, on pendent racemes. The flowers are followed by smooth brown seed pods that are also interesting. Golden locust is one of the cultivars that is grown more for foliage than for its flowers and it does not flower as freely as the species. It does tend to send up suckers. Photo
Sources
This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6 and information provided by J. Frank Schmidt & Son nursery.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist,or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Best Way to Stabilize Trees
By Len Phillips
The recommendation for staking trees has changed in recent years as the result of studies on the effect of wind sway on trees and what happens to staked trees. Trees tied to tall stakes at a point just below the crowns are still a common sight, however this practice, that was once thought to discourage vandalism and support the tree, may not be the best solution.
A research project from a few years ago, evaluated nine different ways to stake trees. Each system was used on newly planted trees and then the trees were pulled over to see which system would provide the most resistance to tree failure during heavy winds. See drawings of all the Tree Staking options or click on the photos in each paragraph below. The results, in alphabetical order, have been summarized as follows:
2 x 2 Staple
The first system was called 2 x 2 Staple because it was made from 2 x 2 lumber with one long piece crossing over the root ball and screwed or nailed to two shorter pieces driven into solid ground on either side of the root ball. They look like wood staple and a pair of these staples are driven into either side of the tree trunk. This system along with the Brooks Tree Brace and Terra Toggle™ (both described below), withstood the largest forces against the tree before failure. The most common mode of failure was when the vertical pieces driven into solid ground were forced up on the opposite side of the pull or wind direction. Breakage of the horizontal 2 x 2 also accounted for some failures. See Photo
ArborBrace
The ArborBrace guying system looks like the conventional guy wire system that has been used for years. During the testing, ArborBrace never came out of the ground and the polypropylene guy wires never snapped. The ArborBrace failed only when the guy wires stretched and cut through the soil, allowing the tree to bend more and the root ball to rotate. ArborBrace’s metal tension buckle remained securely fastened to the guy wire and no slipping occurred. See Photo
Brooks Tree Brace
The Brooks Tree Brace also looks like the conventional guy wire system that has been used for years. Brooks Tree Brace is firmly secured to the trunk allowing minimal movement, which has been shown by other research to negatively impact tree growth at and above the brace at the trunk. As the tree was being pulled, the front two braces in the direction of pull acted as lever arms because they were tightly secured around the trunk and began to lift the root ball out of the ground. The root ball remained above ground level even after the tension from the pulling rope was removed. Other times, the trees all broke at the same spot just above the rubber pads. See Photo
Dowels
The dowel system consists of three long wooden dowels driven through the root ball. During the testing, this system was statistically similar to ArborBrace and ArborTie. The low force to failure for dowels was the result of the root ball rotating toward the direction of pull and easily slipped off the wood dowels. This slipping might be reduced by increasing the diameter of the dowels or by using reinforcing rods (rebar) instead of wood dowels.
Duckbill
Duckbill also looks like the conventional guy wire system. This system withstood the most force before the tree failed. The wires of Duckbill system had little or no stretch but suddenly broke or failed when an anchor was pulled out of the ground. The U-bolt cable clamps that came with the Duckbill also failed to secure the cable under high forces when the tree had the support of two guy wires, allowing the cable to slip periodically despite being tightened adequately. When the tree had the support of only one guy wire, it snapped every time. Duckbill is firmly secured to the trunk allowing minimal movement, which, as mentioned above, negatively impacts tree growth. See Photo
Rebar and ArborTie
ArborTie also looks like the conventional guy wire system. ArborTie was statistically similar to ArborBrace and dowels in terms of force applied to the tree before failure. The rebar pulled out of the ground and/or bent as the tree was pulled over, but the ArborTie never snapped. A larger-diameter rebar would have been more difficult to pull from the ground or bend. ArborTie is firmly secured to the trunk allowing minimal movement, which negatively impacts tree growth. See Photo
Terra Toggle™
The Terra Toggle™ consists of polypropylene strapping holding a piece of lumber and the root ball firmly to the ground with anchors. This system is similar to the 2 x 2 and is installed after the tree is set in the planting pit but before any backfill is added to the hole. The Terra Toggle™, along with the Brooks Tree Brace and 2 × 2’s withstood the largest forces against the tree. The Terra Toggle™ did not break any trees in half but cracked the trunk at the base on the compression side. None of the Terra Toggle™Earth Anchors came out of the ground during testing and they never broke. The strapping would usually slice into the lumber supports that prevented the cable from sliding into the root ball. Occasionally, as tension on the straps increased, a lumber support would become displaced and the strapping would cut into the root ball. This did not impact the strength of the system. See Photo
Tree Staple™
The Tree Staple™ consists of a long metal prong that provides vertical support and serves as an anchor to the firm soil below the root ball. The shorter prong restricts twisting of the root ball movement and firmly locks the root ball in-place. The cross member stretches across a portion of the root ball, applying downward pressure. One person using a sledge hammer can install this system in less than 2 minutes. The wood dowels, Tstakes, and Tree Staple™all required the least amount of time to install. The Tree Staple™ guying system is statistically similar to the ArborBrace and dowels in terms of force against the tree. Tree Staple™ had relatively low force to failure values. On very windy sites, the Tree Staple™ could be improved by increasing the number of Tree Staples™ that are used so that all sides of the tree are supported equally. See Photo
Tstakes
The Tstakes system is similar to the conventional system of using long stakes on either side of the trunk with cables between them holding the tree in place. The Tstakes system secured the trunk two-thirds of the total height of the tree or over the first major limb, consistent with the critical height of staking. The Tstake stabilization system could be improved by using longer stakes so that more of the support was in the ground. Tstakes are firmly secured to the trunk allowing minimal movement, which negatively impacts tree growth, as mentioned above. See Photo
Results
Of the three best systems tested, Brooks Tree Brace took the least amount of time and effort to install but was also the most expensive. The Terra Toggle™ was the least expensive but the recommended installation method required a water source to drive the anchors. The 2 × 2’s could be made “in-house” but installation was the most labor intensive. The rebar and ArborTie, Duckbil, and ArborBrace guying systems were similar considering cost and their effectiveness relative to the other systems tested, and installation was time-consuming but not labor-intensive.
Trunk stabilizing systems that rely on stakes and/or guy wires require a considerable amount of time to install properly. They need to be adjusted and must be removed within 12 months after installation to prevent long-term tree damage. The Tree Staple™ and dowel system were the easiest to install and do not need to be removed.
Where possible, it is usually better to use smaller trees that do not need staking. Furthermore, nursery grown trees have a relatively limited root-spread that makes them vulnerable to wind-throw or vandalism when they are planted in cultivated soil.
Stake & Tie Systems
If a tree is staked and tied just below the crown, the stem cannot sway, and little increase in stem diameter occurs from the flare to the crown. The stem may in fact become thicker above the tie than below it, because diameter growth increases in response to the movement of the crown. A supported tree will initially gain height faster than the unsupported tree, but the stem will be thin and weak up to the tie, and then taper rapidly. As the tree can flex only above the tie, it is all too easy to snap the crown off by using the tie point as a pivot.
There are other disadvantages to staking. Regular maintenance will be needed to check the ties, as these can abrade and even strangle the stem if not adjusted from time to time. Stakes and ties also cost money. Stake and tie systems have the potential to girdle trees, cause bark damage, introduce unnatural stress on the trunk and inhibit proper growth.
On the other hand, the stem diameter growth of a tree is stimulated when it sways in the wind. If a tree is left unstaked, the whole tree, including the stem, will sway, stimulating maximum diameter growth at or near the flare. Over time, this swaying will help form a stout, firm tree with a stem that tapers evenly from flare to crown. The unstaked tree will develop a structure that can flex under the force of wind or vandalism. As roots at the flare also increase in diameter from the movement of the stem, the tree is given added stability.
Stapling Systems
Stapling is a below-grade system that secures new plantings by the root-ball to the bottom of the planting pit. The 2 × 2’s, dowels, Terra Toggle™, and Tree Staple™, are included in this concept. If the aesthetics alone are not enough of an enticement, think in terms of safety for children or pets where the danger of exposed stakes and wires is eliminated. The faster installation, no maintenance or removal, better appearance, and reduced liability are also benefits of these systems.
When the Tree Staple™ concept was introduced, it captured the interest of American Hort, formerly the American Nursery and Landscape Association, who encouraged all municipalities, landscape architects, state governments and landscape installers to consider this alternative to traditional staking and tie specifications. American Hort recommendations refer to research indicating that stake and tie systems may be detrimental to a tree's growth and development. Trees need natural movement to grow properly.
Stapling secures new plantings by the root-ball that provides notable cost savings through quick and easy installation, no need for removal, and it results in a healthier, better looking tree.
Source
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist or BCMA practice credits.
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By Len Phillips
The recommendation for staking trees has changed in recent years as the result of studies on the effect of wind sway on trees and what happens to staked trees. Trees tied to tall stakes at a point just below the crowns are still a common sight, however this practice, that was once thought to discourage vandalism and support the tree, may not be the best solution.
A research project from a few years ago, evaluated nine different ways to stake trees. Each system was used on newly planted trees and then the trees were pulled over to see which system would provide the most resistance to tree failure during heavy winds. See drawings of all the Tree Staking options or click on the photos in each paragraph below. The results, in alphabetical order, have been summarized as follows:
2 x 2 Staple
The first system was called 2 x 2 Staple because it was made from 2 x 2 lumber with one long piece crossing over the root ball and screwed or nailed to two shorter pieces driven into solid ground on either side of the root ball. They look like wood staple and a pair of these staples are driven into either side of the tree trunk. This system along with the Brooks Tree Brace and Terra Toggle™ (both described below), withstood the largest forces against the tree before failure. The most common mode of failure was when the vertical pieces driven into solid ground were forced up on the opposite side of the pull or wind direction. Breakage of the horizontal 2 x 2 also accounted for some failures. See Photo
ArborBrace
The ArborBrace guying system looks like the conventional guy wire system that has been used for years. During the testing, ArborBrace never came out of the ground and the polypropylene guy wires never snapped. The ArborBrace failed only when the guy wires stretched and cut through the soil, allowing the tree to bend more and the root ball to rotate. ArborBrace’s metal tension buckle remained securely fastened to the guy wire and no slipping occurred. See Photo
Brooks Tree Brace
The Brooks Tree Brace also looks like the conventional guy wire system that has been used for years. Brooks Tree Brace is firmly secured to the trunk allowing minimal movement, which has been shown by other research to negatively impact tree growth at and above the brace at the trunk. As the tree was being pulled, the front two braces in the direction of pull acted as lever arms because they were tightly secured around the trunk and began to lift the root ball out of the ground. The root ball remained above ground level even after the tension from the pulling rope was removed. Other times, the trees all broke at the same spot just above the rubber pads. See Photo
Dowels
The dowel system consists of three long wooden dowels driven through the root ball. During the testing, this system was statistically similar to ArborBrace and ArborTie. The low force to failure for dowels was the result of the root ball rotating toward the direction of pull and easily slipped off the wood dowels. This slipping might be reduced by increasing the diameter of the dowels or by using reinforcing rods (rebar) instead of wood dowels.
Duckbill
Duckbill also looks like the conventional guy wire system. This system withstood the most force before the tree failed. The wires of Duckbill system had little or no stretch but suddenly broke or failed when an anchor was pulled out of the ground. The U-bolt cable clamps that came with the Duckbill also failed to secure the cable under high forces when the tree had the support of two guy wires, allowing the cable to slip periodically despite being tightened adequately. When the tree had the support of only one guy wire, it snapped every time. Duckbill is firmly secured to the trunk allowing minimal movement, which, as mentioned above, negatively impacts tree growth. See Photo
Rebar and ArborTie
ArborTie also looks like the conventional guy wire system. ArborTie was statistically similar to ArborBrace and dowels in terms of force applied to the tree before failure. The rebar pulled out of the ground and/or bent as the tree was pulled over, but the ArborTie never snapped. A larger-diameter rebar would have been more difficult to pull from the ground or bend. ArborTie is firmly secured to the trunk allowing minimal movement, which negatively impacts tree growth. See Photo
Terra Toggle™
The Terra Toggle™ consists of polypropylene strapping holding a piece of lumber and the root ball firmly to the ground with anchors. This system is similar to the 2 x 2 and is installed after the tree is set in the planting pit but before any backfill is added to the hole. The Terra Toggle™, along with the Brooks Tree Brace and 2 × 2’s withstood the largest forces against the tree. The Terra Toggle™ did not break any trees in half but cracked the trunk at the base on the compression side. None of the Terra Toggle™Earth Anchors came out of the ground during testing and they never broke. The strapping would usually slice into the lumber supports that prevented the cable from sliding into the root ball. Occasionally, as tension on the straps increased, a lumber support would become displaced and the strapping would cut into the root ball. This did not impact the strength of the system. See Photo
Tree Staple™
The Tree Staple™ consists of a long metal prong that provides vertical support and serves as an anchor to the firm soil below the root ball. The shorter prong restricts twisting of the root ball movement and firmly locks the root ball in-place. The cross member stretches across a portion of the root ball, applying downward pressure. One person using a sledge hammer can install this system in less than 2 minutes. The wood dowels, Tstakes, and Tree Staple™all required the least amount of time to install. The Tree Staple™ guying system is statistically similar to the ArborBrace and dowels in terms of force against the tree. Tree Staple™ had relatively low force to failure values. On very windy sites, the Tree Staple™ could be improved by increasing the number of Tree Staples™ that are used so that all sides of the tree are supported equally. See Photo
Tstakes
The Tstakes system is similar to the conventional system of using long stakes on either side of the trunk with cables between them holding the tree in place. The Tstakes system secured the trunk two-thirds of the total height of the tree or over the first major limb, consistent with the critical height of staking. The Tstake stabilization system could be improved by using longer stakes so that more of the support was in the ground. Tstakes are firmly secured to the trunk allowing minimal movement, which negatively impacts tree growth, as mentioned above. See Photo
Results
Of the three best systems tested, Brooks Tree Brace took the least amount of time and effort to install but was also the most expensive. The Terra Toggle™ was the least expensive but the recommended installation method required a water source to drive the anchors. The 2 × 2’s could be made “in-house” but installation was the most labor intensive. The rebar and ArborTie, Duckbil, and ArborBrace guying systems were similar considering cost and their effectiveness relative to the other systems tested, and installation was time-consuming but not labor-intensive.
Trunk stabilizing systems that rely on stakes and/or guy wires require a considerable amount of time to install properly. They need to be adjusted and must be removed within 12 months after installation to prevent long-term tree damage. The Tree Staple™ and dowel system were the easiest to install and do not need to be removed.
Where possible, it is usually better to use smaller trees that do not need staking. Furthermore, nursery grown trees have a relatively limited root-spread that makes them vulnerable to wind-throw or vandalism when they are planted in cultivated soil.
Stake & Tie Systems
If a tree is staked and tied just below the crown, the stem cannot sway, and little increase in stem diameter occurs from the flare to the crown. The stem may in fact become thicker above the tie than below it, because diameter growth increases in response to the movement of the crown. A supported tree will initially gain height faster than the unsupported tree, but the stem will be thin and weak up to the tie, and then taper rapidly. As the tree can flex only above the tie, it is all too easy to snap the crown off by using the tie point as a pivot.
There are other disadvantages to staking. Regular maintenance will be needed to check the ties, as these can abrade and even strangle the stem if not adjusted from time to time. Stakes and ties also cost money. Stake and tie systems have the potential to girdle trees, cause bark damage, introduce unnatural stress on the trunk and inhibit proper growth.
On the other hand, the stem diameter growth of a tree is stimulated when it sways in the wind. If a tree is left unstaked, the whole tree, including the stem, will sway, stimulating maximum diameter growth at or near the flare. Over time, this swaying will help form a stout, firm tree with a stem that tapers evenly from flare to crown. The unstaked tree will develop a structure that can flex under the force of wind or vandalism. As roots at the flare also increase in diameter from the movement of the stem, the tree is given added stability.
Stapling Systems
Stapling is a below-grade system that secures new plantings by the root-ball to the bottom of the planting pit. The 2 × 2’s, dowels, Terra Toggle™, and Tree Staple™, are included in this concept. If the aesthetics alone are not enough of an enticement, think in terms of safety for children or pets where the danger of exposed stakes and wires is eliminated. The faster installation, no maintenance or removal, better appearance, and reduced liability are also benefits of these systems.
When the Tree Staple™ concept was introduced, it captured the interest of American Hort, formerly the American Nursery and Landscape Association, who encouraged all municipalities, landscape architects, state governments and landscape installers to consider this alternative to traditional staking and tie specifications. American Hort recommendations refer to research indicating that stake and tie systems may be detrimental to a tree's growth and development. Trees need natural movement to grow properly.
Stapling secures new plantings by the root-ball that provides notable cost savings through quick and easy installation, no need for removal, and it results in a healthier, better looking tree.
Source
- Eckstein, Ryan and Edward F. Gilman, “Evaluation of Landscape Tree Stabilization Systems”, Arboriculture & Urban Forestry 34(4): July 2008.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.