#6 Read About Ways to Install Trees
Edited by Len Phillips, updated January 2023
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Edited by Len Phillips, updated January 2023
Sections You may go directly to the section by clicking on titles listed here.
Click on the green text in each section for more information
Summary of Common Options for Installing Trees
Trees can be purchased for planting in several different ways. It is possible to plant some species at any time of the year depending upon the choices of nursery stock and installation methods. Those in hard plastic containers or boxes are most resistant to abusive handling; those in soft, fabric containers and those that are B&B (balled & burlapped) are somewhat sensitive and bare root trees are very sensitive.
Bare root (BR) trees are dug and stored without any soil around their roots. Bare root trees are usually installed while dormant and are ideal for the challenges of urban environments. The BR method utilizes trees up to two inches in caliper and can be substituted for the B&B tree at half the cost while still offering excellent rates of survival and growth. BR trees are becoming more popular by municipalities because of their lower purchase price, lower installation cost, and ease of handling. However, BR tree roots are susceptible to drying out and must be kept moist at ALL times before planting. For more information see Planting Trees at a Bargain Rate.
B&B trees and shrubs are dug with a firm ball of soil around the roots and held securely in place with burlap, twine, and larger trees also sit in a wire basket. The soil ball protects tree roots from water stress during the transplant process. Field-grown plants are best moved while they are dormant. B&B trees are generally produced for homes, parks, and street tree installation projects. The vast majority of B&B trees are dug at less than 4" trunk diameter but larger trees are dug this way as well and boxed rather than wrapped in burlap. The biggest disadvantage of B&B is the tendency to cut corners during the installation process and not remove the burlap and wire basket. This action usually causes death or deformity to the tree within10 years.
Containerized trees are convenient and less expensive than B&B trees. They can be installed anytime the ground is not frozen and are usually easier to handle than B&B trees. Shoot and trunk growth appear to be similar to B&B and BR trees. Containerized trees appear to be more susceptible to desiccation, death, and slower growth until they become established if the roots are not kept moist after the installation. They have a similar survival rate to a BR tree because there is a high root regeneration capacity. However, container trees also have the highest probability of root malformation, which can lead to girdling roots, instability, and a shortened life span. Many experts recommend that since a containerized tree has all its roots, the soil can be washed off and the tree treated and planted as a bare root tree. This approach will identify any root problems that can be corrected before or during planting.
Grow Bags have about half the volume of the root balls of field-grown trees, which makes them easier to handle. Research shows that because the root ball is smaller, there is less water storage capacity. This makes grow bag trees more sensitive to desiccation immediately after digging than are B&B trees grown directly in the nursery.
Tree Spade dug trees are dug, lifted, and transported in less time than any other method. Hydraulic systems operate digging blades that cut the roots and lift the tree in a cone shaped root ball. The tree spade tree is then transported to the new site and the tree is inserted into a previously dug hole. Many nurseries use a tree spade to dig the tree and then set it aside where the B&B crew can remove surplus soil and wrap the roots in burlap. In the time that the tree spade has been around, it has all but put an end to the old-fashioned hand or backhoe dug procedure required for B&B trees.
Summary of Common Options for Installing Trees
Trees can be purchased for planting in several different ways. It is possible to plant some species at any time of the year depending upon the choices of nursery stock and installation methods. Those in hard plastic containers or boxes are most resistant to abusive handling; those in soft, fabric containers and those that are B&B (balled & burlapped) are somewhat sensitive and bare root trees are very sensitive.
Bare root (BR) trees are dug and stored without any soil around their roots. Bare root trees are usually installed while dormant and are ideal for the challenges of urban environments. The BR method utilizes trees up to two inches in caliper and can be substituted for the B&B tree at half the cost while still offering excellent rates of survival and growth. BR trees are becoming more popular by municipalities because of their lower purchase price, lower installation cost, and ease of handling. However, BR tree roots are susceptible to drying out and must be kept moist at ALL times before planting. For more information see Planting Trees at a Bargain Rate.
B&B trees and shrubs are dug with a firm ball of soil around the roots and held securely in place with burlap, twine, and larger trees also sit in a wire basket. The soil ball protects tree roots from water stress during the transplant process. Field-grown plants are best moved while they are dormant. B&B trees are generally produced for homes, parks, and street tree installation projects. The vast majority of B&B trees are dug at less than 4" trunk diameter but larger trees are dug this way as well and boxed rather than wrapped in burlap. The biggest disadvantage of B&B is the tendency to cut corners during the installation process and not remove the burlap and wire basket. This action usually causes death or deformity to the tree within10 years.
Containerized trees are convenient and less expensive than B&B trees. They can be installed anytime the ground is not frozen and are usually easier to handle than B&B trees. Shoot and trunk growth appear to be similar to B&B and BR trees. Containerized trees appear to be more susceptible to desiccation, death, and slower growth until they become established if the roots are not kept moist after the installation. They have a similar survival rate to a BR tree because there is a high root regeneration capacity. However, container trees also have the highest probability of root malformation, which can lead to girdling roots, instability, and a shortened life span. Many experts recommend that since a containerized tree has all its roots, the soil can be washed off and the tree treated and planted as a bare root tree. This approach will identify any root problems that can be corrected before or during planting.
Grow Bags have about half the volume of the root balls of field-grown trees, which makes them easier to handle. Research shows that because the root ball is smaller, there is less water storage capacity. This makes grow bag trees more sensitive to desiccation immediately after digging than are B&B trees grown directly in the nursery.
Tree Spade dug trees are dug, lifted, and transported in less time than any other method. Hydraulic systems operate digging blades that cut the roots and lift the tree in a cone shaped root ball. The tree spade tree is then transported to the new site and the tree is inserted into a previously dug hole. Many nurseries use a tree spade to dig the tree and then set it aside where the B&B crew can remove surplus soil and wrap the roots in burlap. In the time that the tree spade has been around, it has all but put an end to the old-fashioned hand or backhoe dug procedure required for B&B trees.
Installing Bare Root Trees
Bare Root (BR) trees are dug and stored without any soil around their roots. Bare root trees are available as deciduous dormant trees typically 2-inch (5 cm) trunk diameter or less. Bare root trees are very sensitive to drying if not properly stored and shipped. If provisions are made to keep roots in the shade and moist during storage and transport, and they are regularly watered after the installation, they perform as well as trees from other production methods. Evergreens however, are seldom moved BR. Video
BR trees are dug from nursery fields after autumn leaf drop or before spring bud break and are warehoused in a cold storage building with their roots covered with sawdust, straw, or woodchips, or they can be stored in mulch in the field until they are shipped for planting. Some nurseries dip the bare roots into a hydro-gel before placing the tree in a storage building. The hydrogel coats the roots and prevents them from drying out. Autumn-dug trees require humidity and temperature-controlled storage just above freezing. They may be installed in autumn, as soon after digging as possible or in early spring before growth begins. The large woody roots are moved with the tree and new fine roots should develop before the leaves emerge. BR trees have to rely on old roots for water uptake. New roots are grown after bud break. BR stock, if not handled properly, can have high mortality rates. To ensure success when handling or transporting BR stock, keep the roots moist and protected from sun and wind at ALL TIMES. A critical factor for success of the BR method is the short time period between lifting and installation and proper root protection during that interim period. Keep the tree roots always in the shade and soaking wet, while the hole is being dug. If the fine roots (also called root hairs) become dried out, they die and the tree will need a full growing season to replace them before normal growth can continue. If the root hairs are kept moist every second they are out of the ground, new growth will be vigorous.
From my personal experience, I witnessed a bare root maple with a one inch trunk diameter installed right next to a four inch B&B maple of the same species planted the previous year. Four years later the BR tree had grown larger in height and trunk diameter than the four inch B&B tree. However, replicating this much growth is highly dependent on the soil, the handling, the water, the climate, and the species.
In the 1980s and 90’s, bare root tree production declined due to increasing demand for year-round installation and the greater flexibility of container production. BR tree production was primarily used for liner production in the nursery business. In recent years however, there has been a reversal of this trend as arborists and landscape architects rediscover the low cost benefits of BR trees for municipal tree installations. Video
Installation
Before the installation, examine BR trees and prune away any diseased, broken, or damaged roots and branches. Dig the hole three times the width of the roots and install the tree one inch higher than the flare. Center the tree in the hole with the best side facing the public view. Straighten the roots and spread them evenly in all directions away from the trunk, to prevent kinking, crowding, and crossing. If it is a problem, unusually long roots may be pruned back to the standard minimum spread. Next, work the soil firmly under and around the lower roots. When the roots are just covered, add water. The tree may be raised and lowered gently during the watering process to eliminate air pockets and to bring the roots in close contact with the soil. Finish filling the hole with soil and then water thoroughly again by filling a saucer made at the top of the hole.
Use any technique possible to reduce the time the tree roots are exposed to wind and sunlight. Order the trees to be dug within 24 hours before pickup. If this is not possible, be sure they are stored in a cool place. Make sure the trees are delivered in covered, temperature-controlled trucks and that the roots are packed in straw, sawdust or woodchips. Some nurseries dip the tree roots in hydro-gel and place the roots in a plastic bag for shipping. Tell the installation crews, "every 30 seconds the tree's roots are exposed to wind and sun cuts the tree's chance for survival in half". While the actual reduction in life may vary, this does encourage the planting crew to pay attention to the exposed bare roots. You do not want to see a bare root tree lying on the ground while the crew digs the hole.
The key to success is to preserve as many lateral roots as possible because they are critical to maximizing shoot growth after installation.
Packaged Trees and Shrubs
Packaged trees and shrubs typically found in department or lumber stores, are BR plants with their roots packed in moist material such as peat moss, straw, wood shavings, or shingle tow. These trees should be treated as BR trees.
The Pros of BR Tree Installation Most can be purchased from one-third to one-half that of B&B stock. This reduced cost results mainly from the ease of handling as well as the reduced weight and bulk resulting in lower shipping costs.
The Cons of BR Tree installation Only small trees, 2” (5 cm) diameter or less, are typically installed bare root.
Some trees install poorly via bare root as compared with B&B, although many more trees are being successfully installed bare root than was previously thought possible. Most people installing trees have limited experience with BR tree installation. Bare root trees deserve a second look from municipalities.
The best bets for bare root installation are:
Hedge maple (Acer campestre)
Amur maple (Acer ginnala)
Miyabei maple (Acer miyabei)
Norway maple (Acer platanoides)
Sycamore maple (Acer pseudoplatanus)
Red maple (Acer rubrum)
Sugar maple (Acer saccharum)
Tartaricum maple (Acer tartaricum)
Shantung maple (Acer truncatum)
Hybrid Freeman maple (Acer x freemanii)
Red horsechestnut (Aesculus x carnea)
Catalpa (Catalpa speciosa)
Katsura tree (Cercidiphyllum japonicum)
Yellowwood (Cladrastis kentukea)
Gray Dogwood (Cornus foemina)
Cornelian cherry dogwood (Cornus mas)
Ash (Fraxinus spp. In non-EAB areas)
Honeylocust (Gleditsia triacanthos inermis)
Kentucky coffee tree (Gymnocladus dioicus)
Goldenraintree (Koelreuteria paniculata)
Amur Maackia (Maackia amurensis)
Crabapples (Malus spp.)
Persian Parrotia (Parrotia persica)
Amur Corktree (Phellodendron amurense)
London Planetree (Platanus x acerifolia)
Flowering Cherry (Prunus 'Accolade')
Sargent Cherry (Prunus sargentii)
Canada Red Chokecherry (Prunus virginiana)
Callery Pear (Pyrus spp.)
Swamp White Oak (Quercus bicolor)
Pin Oak (Quercus palustris)
Northern Red Oak (Quercus rubra)
Black Locust cultivars (Robinia pseudoacacia cultivars)
Korean Mountain ash (Sorbus alnifolia)
Swedish Mountain ash (Sorbus intermedia)
Oak leaf Mountain ash (Sorbus x hybrida)
Japanese tree lilac (Syringa reticulata)
Linden (Tilia spp.)
Elm hybrids (Ulmus hybrids except 'Frontier')
Siebold Viburnum (Viburnum sieboldii)
Trees of moderate difficulty for bare root installation are:
Alder (Alnus glutinosa)
Serviceberry (Amelanchier spp.)
Birch (Betula spp.)
Hackberry (Celtis occidentalis)
Eastern Redbud (Cercis canadensis)
Turkish Filbert (Corylus colurna)
Hawthorn (Crataegus spp.)
Hardy Rubber Tree (Eucommia ulmoides)
Pin Oak (Quercus palustris)
English Oak (Quercus robur)
Silver Linden (Tilia tomentosa)
Japanese Zelkova (Zelkova serrata)
Trees that will not survive bare root installation are:
Hornbeam (Carpinus spp.)
Smoketree (Cotinus obovatus)
Washington Hawthorn (Crataegus phaenopyrum)
Ginkgo (Ginkgo biloba)
Tuliptree (Liriodendron tulipifera)
Hophornbeam (Ostrya virginiana)
Tupelo (Nyssa sylvatica)
White Oak (Quercus alba)
Scarlet Oak (Quercus coccinea)
Shingle Oak (Quercus imbricaria)
Bur Oak (Quercus macrocarpa)
Chinkapin Oak (Quercus muehlenbergii)
Bald Cypress (Taxodium distichum)
Frontier Elm (Ulmus 'Frontier')
Lacebark Elm (Ulmus parvifolia)
All evergreens
Bare Root (BR) trees are dug and stored without any soil around their roots. Bare root trees are available as deciduous dormant trees typically 2-inch (5 cm) trunk diameter or less. Bare root trees are very sensitive to drying if not properly stored and shipped. If provisions are made to keep roots in the shade and moist during storage and transport, and they are regularly watered after the installation, they perform as well as trees from other production methods. Evergreens however, are seldom moved BR. Video
BR trees are dug from nursery fields after autumn leaf drop or before spring bud break and are warehoused in a cold storage building with their roots covered with sawdust, straw, or woodchips, or they can be stored in mulch in the field until they are shipped for planting. Some nurseries dip the bare roots into a hydro-gel before placing the tree in a storage building. The hydrogel coats the roots and prevents them from drying out. Autumn-dug trees require humidity and temperature-controlled storage just above freezing. They may be installed in autumn, as soon after digging as possible or in early spring before growth begins. The large woody roots are moved with the tree and new fine roots should develop before the leaves emerge. BR trees have to rely on old roots for water uptake. New roots are grown after bud break. BR stock, if not handled properly, can have high mortality rates. To ensure success when handling or transporting BR stock, keep the roots moist and protected from sun and wind at ALL TIMES. A critical factor for success of the BR method is the short time period between lifting and installation and proper root protection during that interim period. Keep the tree roots always in the shade and soaking wet, while the hole is being dug. If the fine roots (also called root hairs) become dried out, they die and the tree will need a full growing season to replace them before normal growth can continue. If the root hairs are kept moist every second they are out of the ground, new growth will be vigorous.
From my personal experience, I witnessed a bare root maple with a one inch trunk diameter installed right next to a four inch B&B maple of the same species planted the previous year. Four years later the BR tree had grown larger in height and trunk diameter than the four inch B&B tree. However, replicating this much growth is highly dependent on the soil, the handling, the water, the climate, and the species.
In the 1980s and 90’s, bare root tree production declined due to increasing demand for year-round installation and the greater flexibility of container production. BR tree production was primarily used for liner production in the nursery business. In recent years however, there has been a reversal of this trend as arborists and landscape architects rediscover the low cost benefits of BR trees for municipal tree installations. Video
Installation
Before the installation, examine BR trees and prune away any diseased, broken, or damaged roots and branches. Dig the hole three times the width of the roots and install the tree one inch higher than the flare. Center the tree in the hole with the best side facing the public view. Straighten the roots and spread them evenly in all directions away from the trunk, to prevent kinking, crowding, and crossing. If it is a problem, unusually long roots may be pruned back to the standard minimum spread. Next, work the soil firmly under and around the lower roots. When the roots are just covered, add water. The tree may be raised and lowered gently during the watering process to eliminate air pockets and to bring the roots in close contact with the soil. Finish filling the hole with soil and then water thoroughly again by filling a saucer made at the top of the hole.
Use any technique possible to reduce the time the tree roots are exposed to wind and sunlight. Order the trees to be dug within 24 hours before pickup. If this is not possible, be sure they are stored in a cool place. Make sure the trees are delivered in covered, temperature-controlled trucks and that the roots are packed in straw, sawdust or woodchips. Some nurseries dip the tree roots in hydro-gel and place the roots in a plastic bag for shipping. Tell the installation crews, "every 30 seconds the tree's roots are exposed to wind and sun cuts the tree's chance for survival in half". While the actual reduction in life may vary, this does encourage the planting crew to pay attention to the exposed bare roots. You do not want to see a bare root tree lying on the ground while the crew digs the hole.
The key to success is to preserve as many lateral roots as possible because they are critical to maximizing shoot growth after installation.
Packaged Trees and Shrubs
Packaged trees and shrubs typically found in department or lumber stores, are BR plants with their roots packed in moist material such as peat moss, straw, wood shavings, or shingle tow. These trees should be treated as BR trees.
The Pros of BR Tree Installation Most can be purchased from one-third to one-half that of B&B stock. This reduced cost results mainly from the ease of handling as well as the reduced weight and bulk resulting in lower shipping costs.
- A BR tree without soil weighs little, so it is easy and inexpensive to transport from the nursery, and to handle when being installed.
- Root damage during nursery lifting operations is far less on BR trees.
- BR trees can have 95% of their roots while B&B trees have only 5% of their roots.
- The installation procedure needed for tree establishment is less demanding. Although BR trees require the same planting-hole diameter, the hole depth may be shallower.
- The root system can be thoroughly inspected for defects.
- The flare can be easily located so the tree is installed at the correct depth at finished grade.
- BR installation can be just as effective as B&B installation for species that tolerate BR installation, if the tree has a small caliper and has been root dipped and pruned early.
- Proper installation depth is easily observed and soil interface problems are avoided.
- BR harvesting does not deplete the nursery of field soil.
- Due to the tree's smaller size and more roots, BR trees recover from transplant shock much faster than all the other installation techniques.
The Cons of BR Tree installation Only small trees, 2” (5 cm) diameter or less, are typically installed bare root.
- Once they leave the nursery, BR trees need to get in the ground within a week unless they are treated with hydrogel, wrapped in plastic bags, or heeled-in a bed of woodchips or gravel and watered daily. See the Missouri Gravel Bed discussion in Topic #7.
- With no soil, the roots can dry out and die if left exposed.
- BR trees need lots of internal moisture, so early spring (before bud break) and late autumn (after leaf fall) are the only good digging/installation times.
- Some species may not be available BR and most retail nurseries may not have BR trees available for sale.
Some trees install poorly via bare root as compared with B&B, although many more trees are being successfully installed bare root than was previously thought possible. Most people installing trees have limited experience with BR tree installation. Bare root trees deserve a second look from municipalities.
The best bets for bare root installation are:
Hedge maple (Acer campestre)
Amur maple (Acer ginnala)
Miyabei maple (Acer miyabei)
Norway maple (Acer platanoides)
Sycamore maple (Acer pseudoplatanus)
Red maple (Acer rubrum)
Sugar maple (Acer saccharum)
Tartaricum maple (Acer tartaricum)
Shantung maple (Acer truncatum)
Hybrid Freeman maple (Acer x freemanii)
Red horsechestnut (Aesculus x carnea)
Catalpa (Catalpa speciosa)
Katsura tree (Cercidiphyllum japonicum)
Yellowwood (Cladrastis kentukea)
Gray Dogwood (Cornus foemina)
Cornelian cherry dogwood (Cornus mas)
Ash (Fraxinus spp. In non-EAB areas)
Honeylocust (Gleditsia triacanthos inermis)
Kentucky coffee tree (Gymnocladus dioicus)
Goldenraintree (Koelreuteria paniculata)
Amur Maackia (Maackia amurensis)
Crabapples (Malus spp.)
Persian Parrotia (Parrotia persica)
Amur Corktree (Phellodendron amurense)
London Planetree (Platanus x acerifolia)
Flowering Cherry (Prunus 'Accolade')
Sargent Cherry (Prunus sargentii)
Canada Red Chokecherry (Prunus virginiana)
Callery Pear (Pyrus spp.)
Swamp White Oak (Quercus bicolor)
Pin Oak (Quercus palustris)
Northern Red Oak (Quercus rubra)
Black Locust cultivars (Robinia pseudoacacia cultivars)
Korean Mountain ash (Sorbus alnifolia)
Swedish Mountain ash (Sorbus intermedia)
Oak leaf Mountain ash (Sorbus x hybrida)
Japanese tree lilac (Syringa reticulata)
Linden (Tilia spp.)
Elm hybrids (Ulmus hybrids except 'Frontier')
Siebold Viburnum (Viburnum sieboldii)
Trees of moderate difficulty for bare root installation are:
Alder (Alnus glutinosa)
Serviceberry (Amelanchier spp.)
Birch (Betula spp.)
Hackberry (Celtis occidentalis)
Eastern Redbud (Cercis canadensis)
Turkish Filbert (Corylus colurna)
Hawthorn (Crataegus spp.)
Hardy Rubber Tree (Eucommia ulmoides)
Pin Oak (Quercus palustris)
English Oak (Quercus robur)
Silver Linden (Tilia tomentosa)
Japanese Zelkova (Zelkova serrata)
Trees that will not survive bare root installation are:
Hornbeam (Carpinus spp.)
Smoketree (Cotinus obovatus)
Washington Hawthorn (Crataegus phaenopyrum)
Ginkgo (Ginkgo biloba)
Tuliptree (Liriodendron tulipifera)
Hophornbeam (Ostrya virginiana)
Tupelo (Nyssa sylvatica)
White Oak (Quercus alba)
Scarlet Oak (Quercus coccinea)
Shingle Oak (Quercus imbricaria)
Bur Oak (Quercus macrocarpa)
Chinkapin Oak (Quercus muehlenbergii)
Bald Cypress (Taxodium distichum)
Frontier Elm (Ulmus 'Frontier')
Lacebark Elm (Ulmus parvifolia)
All evergreens
Installing B&B Trees
It takes only a short time to install a tree, but how it is done can have a lasting impact. Mistakes made during the installation process can cause the tree to die prematurely or struggle for many years and never reach its full potential. One way to prevent problems is to install a properly dug tree, Balled and Burlapped (B&B). B&B is also called Balled in Burlap. B&B trees and shrubs are dug during dormancy with a firm ball of soil around the roots and held securely in place with burlap, twine, and usually a wire basket. Video
Digging the Tree
B&B trees grown in the field are dug with a soil ball surrounding a large number of roots. The ball of soil is contained by burlap that is secured with nails, string, and/or wire. Natural burlap is the preferred material because it will deteriorate in the soil within a few months after installing the tree. Synthetic burlap is occasionally used on root balls, so that the nursery operator can dig the tree several months prior to installing it in the landscape. This pre-digging helps the tree harden off and survive the transplanting into the landscape. Synthetic burlap however, must all be removed from the root ball because it will not deteriorate for several years. There are many reports of synthetic burlap preventing root growth out of the root ball.
One other caution at this point in the digging process deals with the location of the structural roots. There should be two or more of these roots within 1 – 3 inches (2.5 – 7.5 cm) of the soil surface. “First order lateral roots”, “top-most roots”, and “main order roots” are other terms that have been used to describe these roots. The best time to determine root depth is while tagging the trees, before they are dug. If the roots are deeper than 3 inches (7.5 cm), consider rejecting the stock, as the ball of roots will be undersized. This means that if a rootball is dug 18 inches deep, but the top 6 inches is soil piled over the structural roots, then you are only getting 12 inches of roots, which may be too small to support the tree. Fortunately, the nursery industry has recognized this problem and the 2014 edition of the American Standard for Nursery Stock (ANSI Z60.1) has been revised to fix this problem. The complete Nursery Stock Standards is available online from American Hort.
Burlap Cautions
If the root balls are hard and are laced on the sides like an old-fashioned drum, they were dug with the whole root ball intact. There should be no circling or crossing roots visible and the trunk should not wobble in the soil ball. If the burlap is tied on top or the ball is soft, the tree may have been dug bare-root and stuck into the burlap with some soil. This means that you are probably purchasing a bare root tree at the higher B&B price. If the tree appears to be B&B dug but the ball is soft, perhaps it was damaged during delivery. In this situation, reject the tree because it will have very poor chance of survival.
Installation Hole
According to the latest research, B&B trees do best if installed in a large installation area. Loosen the soil in the hole down to the depth of the tree’s root system, and horizontally to a distance of at least three times the length of the roots or the radius of the root ball. Loosening the surrounding soil prior to planting eliminates any compacted soil, and speeds recovery from transplant shock because the roots can quickly grow into the loosened soil.
Root Ball and Basket
The latest research recommends that if the tree has been drum laced, it is to be left intact to support the tree during the initial establishment period, provided that the drum lacing is made of a biodegradable material and it can be removed within a few months. The trees should be in low-profile baskets, which have larger openings designed to overcome concerns about future root strangulation. Also because all the wires are below the top of the root ball, these baskets are not tripping hazards. If low-profile baskets are not available, remove all basket wires down 4-6 inches (10 – 15 cm) below the root ball shoulder to eliminate the wires most likely to make contact with the structural roots. The proper method of handling the basket is to lift the tree from the bottom, not from the basket. To prevent breaking any tree roots, take extra care not to loosen or break the soil ball.
B&B trees can be stored prior to installation for a period of time, provided the trees are all set close together with the root balls touching. The balls should be covered with mulch and watered thoroughly. If the root balls dry out, this will be fatal. If installation is in clayey soil, use trees with a clayey root ball to prevent the root balls from drying out. Or, remove most of the soil from the root ball and install the tree into the clay soil, bare root.
Installation
Before any installation occurs, carefully set the tree in the hole at or slightly higher than it was at the nursery. Begin the installation by backfilling layers of soil around the root ball until one-half of the planting hole is full. Then, all burlap and the top one-third of the wire basket can be removed from the root ball. No burlap should remain above the soil surface as it may act as a wick and dry the root ball. Next, provide the first watering and jiggle the tree slightly to allow the soil to contact the roots. As soon as the water has drained away, backfilling can be completed and a second thorough watering is absolutely essential for the newly installed tree. Water will settle the soil and remove air pockets better than compacting the soil with one’s feet. Tamping can cause soil compaction and slow water penetration and root growth.
Although the trees are being transplanted with only 5% of the roots taken with the tree, pruning half of the tree leaves to compensate for the root loss is no longer recommended. The buds on the branches produce hormones that cause the roots to grow and the leaves produce the sugar energy needed by growing roots, so removing those buds and leaves will slow the establishment of new roots. It is better to keep the roots well watered and growing than to remove the food source for the tree.
Evergreens should not be installed late in autumn unless the roots will have a full month to become established before the ground freezes and there is plenty of soil water available for winter use by the tree. When soil water is frozen, the tree experiences drought like conditions.
Pruning
If pruning was done correctly during production in the nursery, the tree should require very little pruning when being installed, except for removing broken twigs. Wait a couple of years for the tree to establish before starting structural pruning. The transplanting shock often causes the tree to respond with co-dominant leaders. When this happens, the two year wait before pruning is an advantage because the co-dominant leaders will be visible and one leader can be removed during the structural pruning effort.
Watering
In the first year or two, it is important to keep the root ball moist, but not over-watered. The root ball soil is the major source of water for the tree until the root system redevelops. During this period, monitor the moisture in the root ball. The surrounding soils where there are few roots absorbing moisture often stay moist while the root ball quickly dries out.
The use of tree watering bags is gaining popularity, because they deliver water to the right place and the right amount. They are also helpful in reducing labor costs for watering. But we know very little about heat buildup on the trunk under the empty bag. An empty bag may also deflect rainwater away from the base of the tree. It is best to remove the bags during the winter months so they will not harbor pests. They should be used for no more than two growing seasons before the bags are moved on to new trees.
Throughout the warm, summer weather, the tree will need the equivalent of 1 inch (2.5 cm) of rain per week and this water needs to be applied about twice each week. Approximately 5-10 gallons (20 – 40 liters) of water is sufficient to moisten a 20-inch (50 cm) diameter root ball. A 40-inch (100 cm) diameter root ball has more than twice the volume and would require 35-45 gallons (130 – 170 liters).
Another way to measure water need is with the following formula: The tree needs 5 gallons minimum and 5 additional gallons per inch of diameter (DBH); hence a 3 inch DBH tree needs 20 gallons of water per week to equal 1 inch of rainfall, in other words, 5 gallons minimum + (3 X 5) 15 gallons = 20 gallons.
Trunk Protection
Plastic guards can help to protect trunks from mowers, weed whips, and other mechanical injuries. If used, they must be removed before the trunk grows large enough to be damaged by the guards. Where sunscald or frost cracks are common, the trunks of thin and/or smooth-barked trees are sometimes wrapped to prevent injury from winter sun. The preferred wraps are light in color, porous to water, and biodegradable, and should be removed early in the spring.
Stabilizing
Staking, guying, or bracing refer to mechanically supporting the trunk of a newly installed tree to keep it in an upright position. Staking is usually unnecessary for quality trees and properly installed B&B stock. If the root ball is in good condition and has been stabilized by firming the soil around the base with two waterings, the tree is not likely to lean or shift. The exceptions where staking is needed might include very windy sites, sandy root balls, or the potential for vandalism.
According to the latest research, staking is being discouraged and root stabilization is a far better option. Root stabilizers consist of wood or metal devices that hold the root ball firmly at the bottom of the planting pit. These stabilizers are usually hidden by the surface layer of mulch. Removal is optional especially since most of the stabilizers are bio-degradable and disappear after a couple of years. Some products may be pulled up at the end of the first growing season and recycled to new installations. The research has proven that former practice of staking often cause the tree to break where it was tied to the stake. Many other times the ties were never removed and the tree became girdled. These problems will not occur with root stabilizers. For more information on stabilization click here.
Mulching
Once the soil is added to level with the flare, mulch the entire planting circle to conserve soil moisture. The depth will vary with the mulch texture. Finer particle mulch should be 2 inches (5 cm) thick or less, while coarse mulch should be 4 inches (10 cm) thick or less. The mulch should start at least 2-3 inches (5-7.5 cm) from the trunk of the tree. The mulch layer should be 1-3 inches (2-7 cm) deep after settling. Mulch should not be allowed to cover the flare.
Mulch is often incorrectly piled up to 1 ft. (30 cm) deep in a small cone only about 3 ft. (90 cm) wide around the tree. This is sometimes called “volcano mulch”. Volcano mulch is of little benefit to the roots, sheds water, can be potentially damaging to the trunk, and it is aesthetically unpleasant. Sometimes volcano mulch may be covering up a bad installation job or using up the left over mulch after mulching the landscape, a practice that is very wasteful and threatening to the life of the tree.
Fertilization
Drought stress limits the growth of newly installed trees more than any other factor. Until the root system can grow and absorb more water, adding fertilizer to the soil is likely to be ineffective and can be detrimental to root establishment. Fertilizer will cauterize the new developing roots and prohibit their growth. It can act like salt, slowing the movement of water into the roots. Fast acting fertilizer also stimulates the growth of leaves over roots, further aggravating drought like conditions. Fertilizer packets that release fertilizer very slowly, on the other hand, can be beneficial. By the time the packets decompose, the tree has recovered from transplant shock and can take advantage of the available fertilizer.
Pros of B&B Installation
Cons of B&B Installation
It takes only a short time to install a tree, but how it is done can have a lasting impact. Mistakes made during the installation process can cause the tree to die prematurely or struggle for many years and never reach its full potential. One way to prevent problems is to install a properly dug tree, Balled and Burlapped (B&B). B&B is also called Balled in Burlap. B&B trees and shrubs are dug during dormancy with a firm ball of soil around the roots and held securely in place with burlap, twine, and usually a wire basket. Video
Digging the Tree
B&B trees grown in the field are dug with a soil ball surrounding a large number of roots. The ball of soil is contained by burlap that is secured with nails, string, and/or wire. Natural burlap is the preferred material because it will deteriorate in the soil within a few months after installing the tree. Synthetic burlap is occasionally used on root balls, so that the nursery operator can dig the tree several months prior to installing it in the landscape. This pre-digging helps the tree harden off and survive the transplanting into the landscape. Synthetic burlap however, must all be removed from the root ball because it will not deteriorate for several years. There are many reports of synthetic burlap preventing root growth out of the root ball.
One other caution at this point in the digging process deals with the location of the structural roots. There should be two or more of these roots within 1 – 3 inches (2.5 – 7.5 cm) of the soil surface. “First order lateral roots”, “top-most roots”, and “main order roots” are other terms that have been used to describe these roots. The best time to determine root depth is while tagging the trees, before they are dug. If the roots are deeper than 3 inches (7.5 cm), consider rejecting the stock, as the ball of roots will be undersized. This means that if a rootball is dug 18 inches deep, but the top 6 inches is soil piled over the structural roots, then you are only getting 12 inches of roots, which may be too small to support the tree. Fortunately, the nursery industry has recognized this problem and the 2014 edition of the American Standard for Nursery Stock (ANSI Z60.1) has been revised to fix this problem. The complete Nursery Stock Standards is available online from American Hort.
Burlap Cautions
If the root balls are hard and are laced on the sides like an old-fashioned drum, they were dug with the whole root ball intact. There should be no circling or crossing roots visible and the trunk should not wobble in the soil ball. If the burlap is tied on top or the ball is soft, the tree may have been dug bare-root and stuck into the burlap with some soil. This means that you are probably purchasing a bare root tree at the higher B&B price. If the tree appears to be B&B dug but the ball is soft, perhaps it was damaged during delivery. In this situation, reject the tree because it will have very poor chance of survival.
Installation Hole
According to the latest research, B&B trees do best if installed in a large installation area. Loosen the soil in the hole down to the depth of the tree’s root system, and horizontally to a distance of at least three times the length of the roots or the radius of the root ball. Loosening the surrounding soil prior to planting eliminates any compacted soil, and speeds recovery from transplant shock because the roots can quickly grow into the loosened soil.
Root Ball and Basket
The latest research recommends that if the tree has been drum laced, it is to be left intact to support the tree during the initial establishment period, provided that the drum lacing is made of a biodegradable material and it can be removed within a few months. The trees should be in low-profile baskets, which have larger openings designed to overcome concerns about future root strangulation. Also because all the wires are below the top of the root ball, these baskets are not tripping hazards. If low-profile baskets are not available, remove all basket wires down 4-6 inches (10 – 15 cm) below the root ball shoulder to eliminate the wires most likely to make contact with the structural roots. The proper method of handling the basket is to lift the tree from the bottom, not from the basket. To prevent breaking any tree roots, take extra care not to loosen or break the soil ball.
B&B trees can be stored prior to installation for a period of time, provided the trees are all set close together with the root balls touching. The balls should be covered with mulch and watered thoroughly. If the root balls dry out, this will be fatal. If installation is in clayey soil, use trees with a clayey root ball to prevent the root balls from drying out. Or, remove most of the soil from the root ball and install the tree into the clay soil, bare root.
Installation
Before any installation occurs, carefully set the tree in the hole at or slightly higher than it was at the nursery. Begin the installation by backfilling layers of soil around the root ball until one-half of the planting hole is full. Then, all burlap and the top one-third of the wire basket can be removed from the root ball. No burlap should remain above the soil surface as it may act as a wick and dry the root ball. Next, provide the first watering and jiggle the tree slightly to allow the soil to contact the roots. As soon as the water has drained away, backfilling can be completed and a second thorough watering is absolutely essential for the newly installed tree. Water will settle the soil and remove air pockets better than compacting the soil with one’s feet. Tamping can cause soil compaction and slow water penetration and root growth.
Although the trees are being transplanted with only 5% of the roots taken with the tree, pruning half of the tree leaves to compensate for the root loss is no longer recommended. The buds on the branches produce hormones that cause the roots to grow and the leaves produce the sugar energy needed by growing roots, so removing those buds and leaves will slow the establishment of new roots. It is better to keep the roots well watered and growing than to remove the food source for the tree.
Evergreens should not be installed late in autumn unless the roots will have a full month to become established before the ground freezes and there is plenty of soil water available for winter use by the tree. When soil water is frozen, the tree experiences drought like conditions.
Pruning
If pruning was done correctly during production in the nursery, the tree should require very little pruning when being installed, except for removing broken twigs. Wait a couple of years for the tree to establish before starting structural pruning. The transplanting shock often causes the tree to respond with co-dominant leaders. When this happens, the two year wait before pruning is an advantage because the co-dominant leaders will be visible and one leader can be removed during the structural pruning effort.
Watering
In the first year or two, it is important to keep the root ball moist, but not over-watered. The root ball soil is the major source of water for the tree until the root system redevelops. During this period, monitor the moisture in the root ball. The surrounding soils where there are few roots absorbing moisture often stay moist while the root ball quickly dries out.
The use of tree watering bags is gaining popularity, because they deliver water to the right place and the right amount. They are also helpful in reducing labor costs for watering. But we know very little about heat buildup on the trunk under the empty bag. An empty bag may also deflect rainwater away from the base of the tree. It is best to remove the bags during the winter months so they will not harbor pests. They should be used for no more than two growing seasons before the bags are moved on to new trees.
Throughout the warm, summer weather, the tree will need the equivalent of 1 inch (2.5 cm) of rain per week and this water needs to be applied about twice each week. Approximately 5-10 gallons (20 – 40 liters) of water is sufficient to moisten a 20-inch (50 cm) diameter root ball. A 40-inch (100 cm) diameter root ball has more than twice the volume and would require 35-45 gallons (130 – 170 liters).
Another way to measure water need is with the following formula: The tree needs 5 gallons minimum and 5 additional gallons per inch of diameter (DBH); hence a 3 inch DBH tree needs 20 gallons of water per week to equal 1 inch of rainfall, in other words, 5 gallons minimum + (3 X 5) 15 gallons = 20 gallons.
Trunk Protection
Plastic guards can help to protect trunks from mowers, weed whips, and other mechanical injuries. If used, they must be removed before the trunk grows large enough to be damaged by the guards. Where sunscald or frost cracks are common, the trunks of thin and/or smooth-barked trees are sometimes wrapped to prevent injury from winter sun. The preferred wraps are light in color, porous to water, and biodegradable, and should be removed early in the spring.
Stabilizing
Staking, guying, or bracing refer to mechanically supporting the trunk of a newly installed tree to keep it in an upright position. Staking is usually unnecessary for quality trees and properly installed B&B stock. If the root ball is in good condition and has been stabilized by firming the soil around the base with two waterings, the tree is not likely to lean or shift. The exceptions where staking is needed might include very windy sites, sandy root balls, or the potential for vandalism.
According to the latest research, staking is being discouraged and root stabilization is a far better option. Root stabilizers consist of wood or metal devices that hold the root ball firmly at the bottom of the planting pit. These stabilizers are usually hidden by the surface layer of mulch. Removal is optional especially since most of the stabilizers are bio-degradable and disappear after a couple of years. Some products may be pulled up at the end of the first growing season and recycled to new installations. The research has proven that former practice of staking often cause the tree to break where it was tied to the stake. Many other times the ties were never removed and the tree became girdled. These problems will not occur with root stabilizers. For more information on stabilization click here.
Mulching
Once the soil is added to level with the flare, mulch the entire planting circle to conserve soil moisture. The depth will vary with the mulch texture. Finer particle mulch should be 2 inches (5 cm) thick or less, while coarse mulch should be 4 inches (10 cm) thick or less. The mulch should start at least 2-3 inches (5-7.5 cm) from the trunk of the tree. The mulch layer should be 1-3 inches (2-7 cm) deep after settling. Mulch should not be allowed to cover the flare.
Mulch is often incorrectly piled up to 1 ft. (30 cm) deep in a small cone only about 3 ft. (90 cm) wide around the tree. This is sometimes called “volcano mulch”. Volcano mulch is of little benefit to the roots, sheds water, can be potentially damaging to the trunk, and it is aesthetically unpleasant. Sometimes volcano mulch may be covering up a bad installation job or using up the left over mulch after mulching the landscape, a practice that is very wasteful and threatening to the life of the tree.
Fertilization
Drought stress limits the growth of newly installed trees more than any other factor. Until the root system can grow and absorb more water, adding fertilizer to the soil is likely to be ineffective and can be detrimental to root establishment. Fertilizer will cauterize the new developing roots and prohibit their growth. It can act like salt, slowing the movement of water into the roots. Fast acting fertilizer also stimulates the growth of leaves over roots, further aggravating drought like conditions. Fertilizer packets that release fertilizer very slowly, on the other hand, can be beneficial. By the time the packets decompose, the tree has recovered from transplant shock and can take advantage of the available fertilizer.
Pros of B&B Installation
- B&B stock is often the most expensive option, but if handled and installed properly, they are as reliable as container grown stock.
- The most commonly selected form of nursery grown trees is the B&B tree.
- For street plantings, B&B is the style most often used, but more informed cities are beginning to accept bare root stock.
- Fine roots are not disturbed, leading to success and low transplant shock.
- People and contractors installing trees are most familiar with B&B installation.
- Large size plant material may be moved B&B.
Cons of B&B Installation
- B&B trees are often dug with too much soil over the flare and main structural roots resulting in a more shallow and smaller rootball.
- Because of the weight of the soil ball, large B&B trees can be difficult to transport and install without special equipment.
- B&B trees are subject to water stress because of the loss of at least 75% of their root system when they were dug, and the lack of root systems being transplanted.
- There is a possibility that there could be a soil incompatibility between the soil in the root ball and the soil where the tree is expected to grow.
Installing Containerized Trees
Although containerized trees have a complete root system when transplanted, the root system is small and constrained, and care should be taken when installing to be sure the roots are well developed and have not encircled the container. Many arborists and landscape architects promote the practice of installing containerized trees when they are still dormant because trees in full leaf will need constant irrigation to prevent water stress. Root regeneration from containers is slower, especially if the landscape and root ball stay fairly dry after installation. Containerized trees are more sensitive to a lack of water after installation than hardened-off field-grown or bare-root trees that have only a fraction of the fine roots. Video
Circling Roots
Roots that have circled the container should be loosened, cut, or removed. All kinked and girdling roots should be cut or unfolded to radiate from the trunk. Make vertical cuts on the sides of the ball just deep enough to cut the circling roots. Also, make a criss-cross cut across the bottom of the ball. Some of the larger roots should be spread out and into the backfill to encourage rapid plant establishment and sturdier trees.
Container Soil
Good field soil may have a pore space of about 20%. This same soil in a container will have only 5% pore space. Therefore, increasing the pore space with larger soil particles such as gravel, perlite, etc. should enhance the container soil. Poorly drained soil which is soil that drains slowly and/or remains waterlogged for long periods of time is the most common cause of plant mortality. Loosening up soil in the container before installation will solve this problem.
Installation
After the planting site is prepared, carefully remove the container so as not to disturb the root ball. Cutting the container may be necessary. Remember that newly containerized stock may be only slightly rooted.
If installing a tree in autumn, be sure there is at least one month before the soil temperature goes below 50° F (10° C) so that the roots will have a chance to become established before winter. In the center of the prepared area, dig a shallow hole to set the tree. The hole should allow the root ball to sit on solid ground. Once the tree is set in the hole, the flare should be level with or 1" above the final grade.
Containerized trees are just as vulnerable to having their primary roots buried too deeply in the soil ball as other trees, and they need to be inspected for excess soil over the flare before installation. Probe down through the top of the container soil level until the flare is found. To avoid future problems that develop when trees are installed too deep, remove any excess soil from above the flare and make certain that the planting hole is not too deep.
Supplying adequate water to transplanted trees and shrubs is the definitive factor for plant survival and long-term health. However, the water table in a container is much higher than it would be in the soil, so care must be taken to ensure adequate drainage.
American Standard for Nursery Stock (ANSI Z60.1) for Containerized Trees
Tree Trunk Caliper Minimum Container Volume
1" 2.5 cm 5 gallon 20 liter
1¼" 3.1 cm 10 gallon 40 liter
1½" 3.8 cm 10 gallon 40 liter
1¾" 4.2 cm 20 gallon 75 liter
2" 5.0 cm 20 gallon 75 liter
2½" 6.3 cm 30 gallon 100 liter
3" 7.5 cm 45 gallon 180 liter
3½" 8.9 cm 65 gallon 250 liter
4" 10.2 cm 95 gallon 350 liter
4½" 11.5 cm 95 gallon 350 liter
5" 12.7 cm 95 gallon 350 liter
Pros of Containerized Trees
Cons of Containerized Trees
Although containerized trees have a complete root system when transplanted, the root system is small and constrained, and care should be taken when installing to be sure the roots are well developed and have not encircled the container. Many arborists and landscape architects promote the practice of installing containerized trees when they are still dormant because trees in full leaf will need constant irrigation to prevent water stress. Root regeneration from containers is slower, especially if the landscape and root ball stay fairly dry after installation. Containerized trees are more sensitive to a lack of water after installation than hardened-off field-grown or bare-root trees that have only a fraction of the fine roots. Video
Circling Roots
Roots that have circled the container should be loosened, cut, or removed. All kinked and girdling roots should be cut or unfolded to radiate from the trunk. Make vertical cuts on the sides of the ball just deep enough to cut the circling roots. Also, make a criss-cross cut across the bottom of the ball. Some of the larger roots should be spread out and into the backfill to encourage rapid plant establishment and sturdier trees.
Container Soil
Good field soil may have a pore space of about 20%. This same soil in a container will have only 5% pore space. Therefore, increasing the pore space with larger soil particles such as gravel, perlite, etc. should enhance the container soil. Poorly drained soil which is soil that drains slowly and/or remains waterlogged for long periods of time is the most common cause of plant mortality. Loosening up soil in the container before installation will solve this problem.
Installation
After the planting site is prepared, carefully remove the container so as not to disturb the root ball. Cutting the container may be necessary. Remember that newly containerized stock may be only slightly rooted.
If installing a tree in autumn, be sure there is at least one month before the soil temperature goes below 50° F (10° C) so that the roots will have a chance to become established before winter. In the center of the prepared area, dig a shallow hole to set the tree. The hole should allow the root ball to sit on solid ground. Once the tree is set in the hole, the flare should be level with or 1" above the final grade.
Containerized trees are just as vulnerable to having their primary roots buried too deeply in the soil ball as other trees, and they need to be inspected for excess soil over the flare before installation. Probe down through the top of the container soil level until the flare is found. To avoid future problems that develop when trees are installed too deep, remove any excess soil from above the flare and make certain that the planting hole is not too deep.
Supplying adequate water to transplanted trees and shrubs is the definitive factor for plant survival and long-term health. However, the water table in a container is much higher than it would be in the soil, so care must be taken to ensure adequate drainage.
American Standard for Nursery Stock (ANSI Z60.1) for Containerized Trees
Tree Trunk Caliper Minimum Container Volume
1" 2.5 cm 5 gallon 20 liter
1¼" 3.1 cm 10 gallon 40 liter
1½" 3.8 cm 10 gallon 40 liter
1¾" 4.2 cm 20 gallon 75 liter
2" 5.0 cm 20 gallon 75 liter
2½" 6.3 cm 30 gallon 100 liter
3" 7.5 cm 45 gallon 180 liter
3½" 8.9 cm 65 gallon 250 liter
4" 10.2 cm 95 gallon 350 liter
4½" 11.5 cm 95 gallon 350 liter
5" 12.7 cm 95 gallon 350 liter
Pros of Containerized Trees
- Container grown trees are excellent for small to medium sized planting stock.
- Containerized trees are convenient and less expensive than B&B trees.
- Containerized trees can be installed anytime the ground is not frozen or bone dry.
- Containerized trees have a complete root system.
- Copper treatment to the sides of the container and corrugated container designs are eliminating circling root problems, but copper coated containers are also toxic and because of this are losing popularity.
- Specially prepared potting soil for containers is lighter in weight than normal planting soil so the containers are easily moved around at the nursery and at the final installation site.
- Pot-in-pot systems provide stable containers in the nursery, cooler pot temperature, and better trunk taper.
Cons of Containerized Trees
- Because of restricted root development, most containerized trees have to be watered daily before transplanting.
- The roots in the potting soil of the container act as a wick during water uptake by drawing water from the potting soil, thus requiring water more often than normal watering after transplanting.
- Most trees produced in containers are very sensitive to drought injury after installation.
- Roots left in the container too long are often circling or kinked and can cause the tree to fail prematurely. This problem is corrected by careful root pruning before the final installation.
- The differences in water potentials between the potting soil and the native soil will either take water away from the container medium, causing water deficits, or draw water toward the potting soil, causing saturation and limiting oxygen to the roots causing root failure.
- Containers sitting on the ground surface are subject to blowing over on windy days in the nursery, potentially causing branch and crown damage.
- Containers need to be covered and mulched in winter months potentially providing homes for rodents who nibble on the tree bark during the winter.
- Black containers can cause root loss from excessive heat on sunny days.
- Containerized plants take longer to establish.
- The container has limited the volume of the root system.
Containers
There are many container types on the market designed to reduce root circling. Many of them reduce the amount of roots circling the container and the impact on post-transplant survival and growth.
Container Shapes, Sizes & Materials
Containers are manufactured in a variety of shapes and sizes and are constructed from many different materials. These include plastic, aluminum, fabrics, wood, and compressed peat. Roots will begin circling the container edge of all containers if left in the container too long. Some new to the market containers are specially designed to reduce the amount of circling roots.
Tall and narrow containers – Trees from containers that are tall and narrow might survive better than those from other container shapes in well-drained, sites with little irrigation. While roots in the top portion of the root ball may dry out, those at the bottom have a better chance of elongating into the landscape soil before drying up and a premature death. In compacted or poorly drained sites, roots at the bottom of a tall root ball may not help the tree become established because they often die or drown from lack of oxygen.
Short and wide (low-profile) containers – Circling roots are less of a problem in a wide container because if they do develop they are located farther from the trunk. However, circling roots may be present close to the trunk if the tree was in a smaller container before it was transplanted to a larger container. Trees installed into well-drained soil from low-profile containers are more susceptible to drought following installation. However, in poorly drained and compacted soils, they should perform very well because roots are located closer to the soil surface where air is plentiful. Trees in low-profile containers sitting above ground are also much more stable on windy sites.
Air-pruning containers are designed with many holes in the sides and bottom. Some of these are bottomless. Roots at the outside edge of the root ball are air pruned and then branch because their tips are killed by air entering the holes. Few roots are evident on the outside of the root ball but the ball stays together nicely. Air root pruning almost eliminates circling roots and creates a denser root ball on some species. Research studies, however, show no increase in root density.
Ribbed containers – Ribs in a variety of configurations along the insides of containers are designed to prevent roots from circling the inside of the container. Roots are often deflected down vertical ribs to the bottom of the container. Some of these containers also have holes along the ridges and at the bottom. Trees from ridged containers should be transplanted similar to those from traditional, smooth-sided containers. The advantage of purchasing trees grown in these containers is that there may be fewer circling roots and more fibrous roots.
Copper-coated containers – Some container insides are coated with a copper hydroxide compound. Fewer circling roots are produced on trees in these containers. Early tests indicate that following installation into the landscape, root elongation and growth of the shoots and trunk is similar to or slightly greater than growth on trees from conventional, smooth-sided containers. However, copper coated containers are no longer in widespread use due to concerns of toxicity.
Wooden box or metal container – There is no data to suggest that trees grown in wooden boxes or metal containers transplant any differently than those from other containers.
Fiber Containers – Fiber containers breathe like clay containers, which keep the roots cool, and they are biodegradable. Unfortunately, they have a very short life span and the bottoms come off easily from being wet all the time.
Container-in-Container systems – A large container is set permanently in the ground. The tree, in a smaller container is placed in the larger container. The roots stay cool and easily accommodate drip irrigation. This solves the problem that regular containers have, where their roots are killed by the sun heating the outside of the container. Unfortunately, the startup and installation costs of this system are high. This option also eliminates the problem of trees blown over on windy days.
Knit fabric inserts – Thick fabric goes inside of a plastic container. The fabric chokes root tips causing the roots to grow laterally and become more fibrous.
Peat containers – The bottom portion of a peat container can be left on the root ball at the time of installation. The top portion of the container should be removed to prevent moisture from wicking out of the root ball.
Non-ridged containers – Trees are occasionally grown in media or soil placed inside a flexible container made from fabric, mesh, plastic, or other material. Trees from these containers should transplant as traditional container-grown trees provided the root ball remains intact. Root balls may be more fragile in these devices than in ridged containers.
There are a few variations on containers and container growing:
There are many container types on the market designed to reduce root circling. Many of them reduce the amount of roots circling the container and the impact on post-transplant survival and growth.
Container Shapes, Sizes & Materials
Containers are manufactured in a variety of shapes and sizes and are constructed from many different materials. These include plastic, aluminum, fabrics, wood, and compressed peat. Roots will begin circling the container edge of all containers if left in the container too long. Some new to the market containers are specially designed to reduce the amount of circling roots.
Tall and narrow containers – Trees from containers that are tall and narrow might survive better than those from other container shapes in well-drained, sites with little irrigation. While roots in the top portion of the root ball may dry out, those at the bottom have a better chance of elongating into the landscape soil before drying up and a premature death. In compacted or poorly drained sites, roots at the bottom of a tall root ball may not help the tree become established because they often die or drown from lack of oxygen.
Short and wide (low-profile) containers – Circling roots are less of a problem in a wide container because if they do develop they are located farther from the trunk. However, circling roots may be present close to the trunk if the tree was in a smaller container before it was transplanted to a larger container. Trees installed into well-drained soil from low-profile containers are more susceptible to drought following installation. However, in poorly drained and compacted soils, they should perform very well because roots are located closer to the soil surface where air is plentiful. Trees in low-profile containers sitting above ground are also much more stable on windy sites.
Air-pruning containers are designed with many holes in the sides and bottom. Some of these are bottomless. Roots at the outside edge of the root ball are air pruned and then branch because their tips are killed by air entering the holes. Few roots are evident on the outside of the root ball but the ball stays together nicely. Air root pruning almost eliminates circling roots and creates a denser root ball on some species. Research studies, however, show no increase in root density.
Ribbed containers – Ribs in a variety of configurations along the insides of containers are designed to prevent roots from circling the inside of the container. Roots are often deflected down vertical ribs to the bottom of the container. Some of these containers also have holes along the ridges and at the bottom. Trees from ridged containers should be transplanted similar to those from traditional, smooth-sided containers. The advantage of purchasing trees grown in these containers is that there may be fewer circling roots and more fibrous roots.
Copper-coated containers – Some container insides are coated with a copper hydroxide compound. Fewer circling roots are produced on trees in these containers. Early tests indicate that following installation into the landscape, root elongation and growth of the shoots and trunk is similar to or slightly greater than growth on trees from conventional, smooth-sided containers. However, copper coated containers are no longer in widespread use due to concerns of toxicity.
Wooden box or metal container – There is no data to suggest that trees grown in wooden boxes or metal containers transplant any differently than those from other containers.
Fiber Containers – Fiber containers breathe like clay containers, which keep the roots cool, and they are biodegradable. Unfortunately, they have a very short life span and the bottoms come off easily from being wet all the time.
Container-in-Container systems – A large container is set permanently in the ground. The tree, in a smaller container is placed in the larger container. The roots stay cool and easily accommodate drip irrigation. This solves the problem that regular containers have, where their roots are killed by the sun heating the outside of the container. Unfortunately, the startup and installation costs of this system are high. This option also eliminates the problem of trees blown over on windy days.
Knit fabric inserts – Thick fabric goes inside of a plastic container. The fabric chokes root tips causing the roots to grow laterally and become more fibrous.
Peat containers – The bottom portion of a peat container can be left on the root ball at the time of installation. The top portion of the container should be removed to prevent moisture from wicking out of the root ball.
Non-ridged containers – Trees are occasionally grown in media or soil placed inside a flexible container made from fabric, mesh, plastic, or other material. Trees from these containers should transplant as traditional container-grown trees provided the root ball remains intact. Root balls may be more fragile in these devices than in ridged containers.
There are a few variations on containers and container growing:
- Field-containerized nursery stocks - are field-grown plants dug with a ball of field soil intact which is then placed in a container. These plants should be sold and installed during the spring, as field soil will not provide good plant growth in a container. It is important that the root ball be disturbed as little as possible during the digging and installation process.
- Containerized trees and shrubs - are dug from the nursery in the spring or autumn as bare rootstock, placed in a container with a special growing medium, and sold in the container. If containerized in early spring, most plants will be sufficiently established in the container and can be transplanted in late spring, summer, or autumn. Roots must be established in the container and hold the media together before transplanting. Do not completely break up the root ball at installation time, but do cut any circling roots prior to installation. The tighter the root ball, the more the root system should be disturbed to eliminate circling roots and spread the root system out horizontally.
- Container grown stock - has been growing in a container throughout most of its lifetime. Because the roots of these plants are not disturbed at the time of installation, container-grown plants suffer little transplant shock and may be installed at any time during the growing season. Plants that have outgrown their containers may have deformed root systems, which can result in girdling, deformed, or "J" roots. Large plants may be root bound in the container. The root ball of these plants must be torn or cut open to eliminate subsequent circling or girdling roots.
- Packaged trees and shrubs - are BR plants with their roots packed in moist material such as peat moss,
straw, wood shavings, or shingle tow. Install them in early spring before growth starts. Keep packing materials moist, and keep the package cool and shaded until installed. These trees should be considered BR trees and are frequently found in retail lumber and general stores.
- AGS (Above-ground System) - is a double plastic container system whereby a production container nests inside a double-walled holder container. The AGS serves to insulate plant roots from temperature extremes and its wide base helps reduce container blow-over.
- Low-profile containers - come with several variations on this theme, but in general, all are wide, shallow, bottomless containers that sit on plastic or other synthetic fabrics. Trees produced with low-profile
containers develop a shallow, broad root system that more closely approximates their natural root profile. Roots are air-pruned at the container wall and become fibrous. The lower height and increased width also increases water retention while reducing the likelihood of the trees blowing over. Trees growing under this system are usually growing in a pine bark soil-less mix that is lightweight and easy to handle. They are installed in shallow holes and quickly recover from transplanting.
- The Accelerator™ - is a low profile container constructed from a thick undulate piece of aluminum alloy. The aluminum is coiled into a cylinder with its polished surface facing outward. The cylinder is fastened in place with two screws. The outward facing undulations have a series of vertical slits running up and down the container sides that serve as air root pruning locations. Undulations serve to direct roots to the pruning slits. The container rests on a fabric panel that permits the growth of small diameter roots into the soil beneath the unit, thereby reducing the chance of blow-over.
- The RootBuilder system - developed by Dr. Carl Whitcomb, works much like the Accelerator™, except that instead of aluminum, this low-profile container system uses plastic with honeycomb-like holes for container sides. A plastic or fabric weed barrier serves as the container bottom. According to a nurseryman in Illinois, "trees grown in the RootBuilder develop a fibrous root system instead of circling roots and the product will last 4 to 6 years".
- Soil Sock - containers are a combination of a wire basket and a porous foam-rubber liner. The liner insulates roots from temperature extremes, and prevents root circling by air-pruning them at the liner periphery. The entire unit is designed to be installed intact. Researchers report extensive root growth through the liner and into the surrounding soil on trees installed with the soil sock.
- Pot Pruner container liners - made of styrene show promise for moderating container substrate temperatures. Root Control, Inc. has taken this idea and introduced the Pot Pruner, a fabric sleeve that fits inside the nursery container. According to the manufacturer, this product provides root insulation and accomplishes root pruning without the use of toxic copper paint.
- Copper Treated - containers that have CuCO3 or Cu (OH)2 on the container walls to reduce circling and the matting roots. The copper inhibits root elongation and encourages a fibrous root system of subordinate lateral roots.
Installing Grow Bag Trees
Grow bags are very popular for use in nurseries and containerized tree growing operations to restrict the root spread of trees and promote a root system with more finer roots, than a traditionally field grown root ball. Heavy duty plastic grow bags have been a mainstay in nurseries and greenhouses for years. Grow bags, also called in-ground fabric bags, root control bags, and fabric containers, feature heavy-duty plastic construction, are often fluted, have pre-punched bottom drainage holes, and easily stand upright when filled with soil mix. They range in size from small hanging versions to large specially treated plastic bags that hold up to 11 gallons of soil. They are most commonly available in 1, 3, and 5-gallon sizes. Just lay them on the ground and add soil, fertilizer, trees, and water. These flexible grow bags stimulate extensive fibrous root growth with increased survival rate following transplanting than trees grown in rigid containers. However, the trees grown too long in the bags will become root-bound just like container grown trees. Grow bags are capable of withstanding several years of weathering. The black plastic absorbs the sun's rays, which heats up the soil mix, and subsequently encourages faster, stronger growth. Video
Fabric Container Grown Trees
Some nurseries produce trees in fabric containers in field soil. Irrigation and fertilizer applied only to the top of the root ball will help increase roots in the ball better than irrigation and fertilizer applied to a larger area around the container. Typically, root balls grown in grow bags are harvested from the ground in the dormant season and potted into solid wall containers. Less commonly, they are sold directly to the landscape industry. Root balls of field grown trees contain the same amount of roots as those grown in fabric containers except that fabric container grown root balls are less than half the volume. Their small volume makes these trees easier to handle but because the root ball is smaller, there is less water storage capacity. Combined with a dense root system, this lesser reserve makes trees produced in fabric containers more sensitive to desiccation immediately after digging than trees grown directly in field soil. Nursery operators should make provisions for delivering the irrigation needed to prevent desiccation immediately after harvesting.
Some growers produce trees in fabric containers above ground. The fabric allows air and the fabric itself to prune roots. The result is a reduction in the amount of circling roots and an increase in the amount of fibrous roots.
Digging
Trees grown in fabric containers are easier to lift than the same size trees balled and burlapped (B&B) because they have a smaller root ball. However, they must be handled very carefully because unlike being in a rigid plastic container, the roots are easily broken and so the bag should be wrapped like a B&B plant.
Handling at the Installation Site
Soil inside the ball can become loose from just a moderate disturbance. Never drop the ball because roots will lose contact with soil and trees may go into shock, and then are more likely to die quickly. Always remove all fabric before carefully sliding it into the planting hole. The current installation procedure that requires a large, tapered hole, makes it easy to remove the fabric right beside the tree's final location. Some fabric container designs allow only small-diameter roots to develop outside the fabric. Fabric on these trees will be easy to remove without disturbing the root ball. Other fabrics allow large roots to develop through the fabric. This type of fabric is more challenging to remove. A hand pruner can be used to cut large-diameter roots flush with the inside of the fabric to make removal easier.
Fabric container grown trees also require more frequent irrigation than B&B trees until they are established in the landscape. They will also require root stabilization to hold the trees upright. These trees are rarely installed directly into the landscape because of mishandling and poor understanding of the product.
Several in-ground fabric containers, using various designs and fabrics, have been produced in recent years. All of these fabric in-ground containers are removed from the field at harvest, with the containers not being removed until trees are transplanted.
A new in-ground fabric container allows for the lateral exchange of water between the native soil and the container. It is coated with an herbicide that keeps the roots from growing through the fabric. No root loss should occur at harvest, whereas up to 20% of roots may be lost using other types of in-ground fabric containers. But if trees are received with grow bags still attached to the root balls; they must be removed at installation time to prevent root deformation.
Pros of Grow Bags
Cons of Grow Bags
Grow bags are very popular for use in nurseries and containerized tree growing operations to restrict the root spread of trees and promote a root system with more finer roots, than a traditionally field grown root ball. Heavy duty plastic grow bags have been a mainstay in nurseries and greenhouses for years. Grow bags, also called in-ground fabric bags, root control bags, and fabric containers, feature heavy-duty plastic construction, are often fluted, have pre-punched bottom drainage holes, and easily stand upright when filled with soil mix. They range in size from small hanging versions to large specially treated plastic bags that hold up to 11 gallons of soil. They are most commonly available in 1, 3, and 5-gallon sizes. Just lay them on the ground and add soil, fertilizer, trees, and water. These flexible grow bags stimulate extensive fibrous root growth with increased survival rate following transplanting than trees grown in rigid containers. However, the trees grown too long in the bags will become root-bound just like container grown trees. Grow bags are capable of withstanding several years of weathering. The black plastic absorbs the sun's rays, which heats up the soil mix, and subsequently encourages faster, stronger growth. Video
Fabric Container Grown Trees
Some nurseries produce trees in fabric containers in field soil. Irrigation and fertilizer applied only to the top of the root ball will help increase roots in the ball better than irrigation and fertilizer applied to a larger area around the container. Typically, root balls grown in grow bags are harvested from the ground in the dormant season and potted into solid wall containers. Less commonly, they are sold directly to the landscape industry. Root balls of field grown trees contain the same amount of roots as those grown in fabric containers except that fabric container grown root balls are less than half the volume. Their small volume makes these trees easier to handle but because the root ball is smaller, there is less water storage capacity. Combined with a dense root system, this lesser reserve makes trees produced in fabric containers more sensitive to desiccation immediately after digging than trees grown directly in field soil. Nursery operators should make provisions for delivering the irrigation needed to prevent desiccation immediately after harvesting.
Some growers produce trees in fabric containers above ground. The fabric allows air and the fabric itself to prune roots. The result is a reduction in the amount of circling roots and an increase in the amount of fibrous roots.
Digging
Trees grown in fabric containers are easier to lift than the same size trees balled and burlapped (B&B) because they have a smaller root ball. However, they must be handled very carefully because unlike being in a rigid plastic container, the roots are easily broken and so the bag should be wrapped like a B&B plant.
Handling at the Installation Site
Soil inside the ball can become loose from just a moderate disturbance. Never drop the ball because roots will lose contact with soil and trees may go into shock, and then are more likely to die quickly. Always remove all fabric before carefully sliding it into the planting hole. The current installation procedure that requires a large, tapered hole, makes it easy to remove the fabric right beside the tree's final location. Some fabric container designs allow only small-diameter roots to develop outside the fabric. Fabric on these trees will be easy to remove without disturbing the root ball. Other fabrics allow large roots to develop through the fabric. This type of fabric is more challenging to remove. A hand pruner can be used to cut large-diameter roots flush with the inside of the fabric to make removal easier.
Fabric container grown trees also require more frequent irrigation than B&B trees until they are established in the landscape. They will also require root stabilization to hold the trees upright. These trees are rarely installed directly into the landscape because of mishandling and poor understanding of the product.
Several in-ground fabric containers, using various designs and fabrics, have been produced in recent years. All of these fabric in-ground containers are removed from the field at harvest, with the containers not being removed until trees are transplanted.
A new in-ground fabric container allows for the lateral exchange of water between the native soil and the container. It is coated with an herbicide that keeps the roots from growing through the fabric. No root loss should occur at harvest, whereas up to 20% of roots may be lost using other types of in-ground fabric containers. But if trees are received with grow bags still attached to the root balls; they must be removed at installation time to prevent root deformation.
Pros of Grow Bags
- Smaller size makes them easier to handle.
- Establishment in the container does not require a full growing season.
- This procedure provides the quality of top growth that can only be achieved in the field, but does so with
the convenience and mobility of plants grown in containers. - Certain containers can be used over and over again.
- No heavy equipment or tree spades are necessary.
- Because the trees have not been in the container for numerous years, the circling roots of conventional containers are not a problem.
- Growing trees in the field in grow bags, and then establishing them in containers before sale, provide the maximum of energy for root growth. Install these trees grown into the landscape between May and September and by the following summer the trees are established. Losses are few, stress tolerance is high, and customer satisfaction is excellent.
Cons of Grow Bags
- More fragile than the root balls of B&B trees
- Dry out faster than the root balls of B&B tree
Installation with a Tree Spade
In the late 1960s, Vermeer® virtually revolutionized the landscaping industry by introducing tree spades to dig, lift, and transport trees in less time. Hydraulic systems operate the digging blades. In the time that the tree spade has been around, it has all but put an end to the old-fashioned hand or backhoe dug procedures. However, the advent of the tree spade has made contributions not only to arborists who own them but to the trees they transplant. The use of mechanical tree spades has become a common method of tree installation. Most models feature narrow, open-frame designs, short towers, optional rear-half swivels, special outriggers, and safety lockouts. Mobile tree installers include truck-mounted, trailer-mounted, and loader-mounted models available in single, dual, triple and quad spade configurations. Of course, prior to digging or installation with a tree spade, locate all utilities to prevent cutting through wires, cables, etc. Trees with sparse root systems and trees that have not been root pruned are best dug with a tree spade. Video
Digging
The same ratio of tree caliper to root ball size should be followed as for other methods of digging trees. Using a tree spade too small for the tree size will result in tree failure. Trees should be watered thoroughly before moving to hydrate the plant and to avoid soil sifting out during transport. The tree to be moved should have the lower branches tied up so they will not be broken when the tree spade wraps the blades around it. Once the spade is in place the blades are lowered one at a time until they have completely entered the soil. Caution should be used to be sure the blades do not cut too many roots. Then the tree is lifted by the spades and moved to the pre-dug hole or placed in a basket for B&B purposes.
Installation
The tree is lowered into a pre-dug hole, and adjustments should be made to vertically straighten out the tree before the blades are removed. Trees should be placed at or slightly higher than the original grade to allow for settling. After installation and the blades have been lifted, work loose soil into the area between the hole and the tree plug, and water thoroughly. Supplying adequate water to transplanted trees and shrubs is the definitive factor for tree survival and long-term health. It greatly overrides the negative effects of soil compaction, nutrient deficiencies and turf competition, and amplifies the benefits of organic and microbial amendments, deep cultivation and surface mulching. Poorly drained soil – soil that percolates slowly and/or remains water-logged for long periods of time – is the most common cause of plant mortality.
The tree and root ball may stay in the machine as it is moved to its new location and installed into a pre-dug hole. It may also be placed into a wire basket lined with burlap where it can become a B&B tree. An experienced tree spade operator can make the difference between success and failure. Matching soils from the digging site to the installation site is also important, as is compaction within the installation hole. Trees can be moved in most seasons with a spade, although trees dug in summer and early autumn should have an oversized ball and receive special attention relative to species, condition, handling, and irrigation.
Pros of Using a Tree Spade
Cons of Using a Tree Spade
The spade can glaze the soil especially if there is high clay content. Glazing retards root penetration from the root ball into the surrounding soil, but this problem can be corrected by roughening the sides of the hole with a shovel, rake, etc., to break up the compaction prior to installation. Many owners of tree spades are also welding bumps of metal to the outside of the spades to roughen the holes.
In the late 1960s, Vermeer® virtually revolutionized the landscaping industry by introducing tree spades to dig, lift, and transport trees in less time. Hydraulic systems operate the digging blades. In the time that the tree spade has been around, it has all but put an end to the old-fashioned hand or backhoe dug procedures. However, the advent of the tree spade has made contributions not only to arborists who own them but to the trees they transplant. The use of mechanical tree spades has become a common method of tree installation. Most models feature narrow, open-frame designs, short towers, optional rear-half swivels, special outriggers, and safety lockouts. Mobile tree installers include truck-mounted, trailer-mounted, and loader-mounted models available in single, dual, triple and quad spade configurations. Of course, prior to digging or installation with a tree spade, locate all utilities to prevent cutting through wires, cables, etc. Trees with sparse root systems and trees that have not been root pruned are best dug with a tree spade. Video
Digging
The same ratio of tree caliper to root ball size should be followed as for other methods of digging trees. Using a tree spade too small for the tree size will result in tree failure. Trees should be watered thoroughly before moving to hydrate the plant and to avoid soil sifting out during transport. The tree to be moved should have the lower branches tied up so they will not be broken when the tree spade wraps the blades around it. Once the spade is in place the blades are lowered one at a time until they have completely entered the soil. Caution should be used to be sure the blades do not cut too many roots. Then the tree is lifted by the spades and moved to the pre-dug hole or placed in a basket for B&B purposes.
Installation
The tree is lowered into a pre-dug hole, and adjustments should be made to vertically straighten out the tree before the blades are removed. Trees should be placed at or slightly higher than the original grade to allow for settling. After installation and the blades have been lifted, work loose soil into the area between the hole and the tree plug, and water thoroughly. Supplying adequate water to transplanted trees and shrubs is the definitive factor for tree survival and long-term health. It greatly overrides the negative effects of soil compaction, nutrient deficiencies and turf competition, and amplifies the benefits of organic and microbial amendments, deep cultivation and surface mulching. Poorly drained soil – soil that percolates slowly and/or remains water-logged for long periods of time – is the most common cause of plant mortality.
The tree and root ball may stay in the machine as it is moved to its new location and installed into a pre-dug hole. It may also be placed into a wire basket lined with burlap where it can become a B&B tree. An experienced tree spade operator can make the difference between success and failure. Matching soils from the digging site to the installation site is also important, as is compaction within the installation hole. Trees can be moved in most seasons with a spade, although trees dug in summer and early autumn should have an oversized ball and receive special attention relative to species, condition, handling, and irrigation.
Pros of Using a Tree Spade
- The tree spade, also known as an air spade, initially was intended to make it easier to dig up, move or transplant larger specimen-size trees, commonly those larger than the balled and burlapped varieties found at the nursery. The objective was to find an easier and therefore more profitable method of taking and transplanting trees for “instant” shade, impact, or beauty.
- High survivability rates.
- The compound form and angle of the spade makes a compact root ball.
- The precise cutting nature of the mechanism and the spade carrying the tree means the roots and root hairs remain in contact with the soil.
- The tree spade reduces labor for digging at the nursery site and installation at the landscape site.
- Allows large sized trees to be moved anytime during the growing season.
- When done correctly, the success rate of transplanting with a tree spade is usually excellent.
Cons of Using a Tree Spade
The spade can glaze the soil especially if there is high clay content. Glazing retards root penetration from the root ball into the surrounding soil, but this problem can be corrected by roughening the sides of the hole with a shovel, rake, etc., to break up the compaction prior to installation. Many owners of tree spades are also welding bumps of metal to the outside of the spades to roughen the holes.
Moving Trees with Air
Bare root (BR) transplanting with high pressure air is actually an old method using modern tools and technology developed in the late 1990's. The Air-Spade® was introduced to the tree industry and promoted mainly to diagnose and treat root problems. The Air-Spade®, a pneumatic soil excavating tool, is a venturi nozzled apparatus that attaches to an air compressor modified to generate a supersonic velocity column of air to dislodge soil. When used around trees, it can:
When the pneumatic soil excavating tool is being used for transplanting trees BR, the soil is blown from above and below the roots. This process allows the tree to retain up to 95% of the root mass, which results in little or no transplant shock. This technique provides the ability to transplant trees throughout the growing season (spring, summer, and fall) with success. After air spading, the bare roots are sprayed with water and covered with wet burlap for transporting. Regardless of the weather, season, and species, most trees do not even show signs of wilt during the air spading and moving process.
Steps for Moving Trees with a Pneumatic Soil Excavating Tool
Advantages:
People who have used this technique are confident that bare root transplanting is perhaps the best way to relocate a tree and the Air-Spade® will revolutionize transplanting in our industry.
Bare root (BR) transplanting with high pressure air is actually an old method using modern tools and technology developed in the late 1990's. The Air-Spade® was introduced to the tree industry and promoted mainly to diagnose and treat root problems. The Air-Spade®, a pneumatic soil excavating tool, is a venturi nozzled apparatus that attaches to an air compressor modified to generate a supersonic velocity column of air to dislodge soil. When used around trees, it can:
- reduce soil compaction,
- till the soil,
- reveal girdling roots,
- locate the flare,
- locate roots for underground utility installation,
- investigate root damage,
- check the adequacy of the root structure,
- accurately diagnosis root diseases.
When the pneumatic soil excavating tool is being used for transplanting trees BR, the soil is blown from above and below the roots. This process allows the tree to retain up to 95% of the root mass, which results in little or no transplant shock. This technique provides the ability to transplant trees throughout the growing season (spring, summer, and fall) with success. After air spading, the bare roots are sprayed with water and covered with wet burlap for transporting. Regardless of the weather, season, and species, most trees do not even show signs of wilt during the air spading and moving process.
Steps for Moving Trees with a Pneumatic Soil Excavating Tool
- Hydrate the tree's roots thoroughly before excavating it. Water deeply at least 72 hours before the move. Clay soil blows out best when it is damp. Sandy soil blows out best when it has drained a bit.
- Tie up any branches that may be in the way during the excavation, moving, and backfilling process.
- Start the excavation process by making a circular trench at the drip line using a small backhoe. With that completed, continue using the backhoe to carefully excavate inward toward the trunk until roots are discovered. Then begin using the Air-Spade® by blowing soil outward and into the circular trench.
- Keep the exposed roots as moist as possible during the digging and lifting the roots. As a section is completed, the roots are gathered and tied up in a pigtail fashion, then the pigtail is raised and tied to the tree trunk or lower branches as the roots are moistened again. The Air-Spade® does cause some root drying so moistening the exposed roots is very important.
- Continue this process moving around the tree.
- Once all of the roots are exposed and tied up to the tree, the tree is ready to be moved to the new location, which has been dug the same size as the hole from which the tree is being removed.
- Use a fork lift to lift and transport the tree to its new location.
- Plant the tree at the same grade as it was in its original location, taking care to ensure the flair is at the finished grade. The new planting hole will not have to be very deep.
- Untie the roots from the pigtails and spread them out in approximately their same orientation from which they came. Moisten the roots again.
- Options at this point include adding some soil amendments like compost or a fertilizer to promote root growth.
- Backfill with the soil excavated from the new location. The best way to backfill is with labor and shovels. However if equipment is used, be sure it is equipped with wide tracks or tires. Soil compaction is not acceptable after all this effort to protect and save the tree.
- Untie any low branches that may have been tied up to provide clearance under the tree.
- Build a berm of soil at the edge of the new planting excavation.
- Immediately after backfilling, flood the saucer area with water to eliminate air pockets.
- Continue to irrigate the tree throughout the growing season to ensure the tree becomes established.
- Staking is not necessary. If the tree is on a windy site consider adding root staples or other means for anchoring the roots to the bottom of the planting hole.
Advantages:
- As little as 5% – 15% of roots are cut, unlike the conventional methods which cut between 50% – 85% of the root mass. Most of the trees roots are moved with the tree, compared to 30% with a tree spade or 5% by B&B. This means a minimized transplant shock. The tree is also significantly lighter in weight for transporting.
- The Air-Spade® is considered a less expensive option to transplanting than with a tree spade.
- In addition, smaller machines are needed to lift and move the tree.
- The Air-Spade® is useful for transplanting specimen trees.
- Guying is not required.
People who have used this technique are confident that bare root transplanting is perhaps the best way to relocate a tree and the Air-Spade® will revolutionize transplanting in our industry.
Moving Big Trees
Moving large mature trees is a specialty that requires experience and the proper equipment. Start by performing an inspection of the tree and site to determine the likelihood for survival and performance after relocation. The tree must be healthy and vigorous. The tree must be inspected for pests and disease, included bark, girdling roots, as well as cavities and decay. Structural integrity is also important since many trees are relocated to areas where failure is likely. Species must also be considered, as there are several that do not respond well to relocation. Video
Before modern heavy equipment was available to handle the weight of large root balls, trees 15 inches (38 cm) DBH and greater were moved bare root and eventual survival was low. Today large trees are moved with a soil ball that requires extensive knowledge of both arboriculture and heavy equipment. Mature size trees have been moved successfully, but the cost is very high, and it may take decades for larger trees to fully establish at the new site. Root balls can weigh from 100 to 500 tons and crowns can be up to 80 ft (53 m) tall and just as wide. There are very few contractors that specialize and are capable of moving trees of this size. Also, because of the size and weight, very large trees are best moved when the ground is dry or frozen. The rigid boxes and sophisticated lifting systems result in little root ball shifting.
Moving Trees
Special procedures must be used to minimize water stress in large trees. Proper root pruning prior to transplanting can help along with thinning the crown to reduce transpiration. Some contractors install sprinkler heads throughout the crown after installation to cool the foliage and reduce transpiration. Research suggests this practice may be necessary for only a few weeks until new root development begins. Watering and no pruning will be essential during periods of actual drought. The use of treatments to prevent the spread of disease can also be beneficial.
Trees small enough to use typical B&B root ball procedures of 12 in (30 cm) DBH are moved with commonly available tree spades mounted on winch trucks and cranes. The largest tree spade can dig a 14 ft (4.25 m) diameter root ball but because of the difficulty and cost of transporting this machine, it is probably only realistic to use this machine on large jobs with many trees to move.
Cranes are used to lift the largest trees by both the root ball and the branches. Tensions must be even on all cables to avoid damaging branches. Using the sound made by the cable when struck with a hammer to judge cable tension (like tuning a piano string) is an example of the very specialized methods used by experienced contractors. An inexperienced contractor can leave the wrong tension on the cables and that could cause branches to break or cause the tree to separate from its roots.
The method preferred in sandy soils where root balls may break is to lift the tree by one or two heavy steel pins inserted in holes drilled through the trunk. These pins are used to lift the tree in the upright position by both the pins and the root ball at the same time. The drawback of this method is the injury to the trunk, and the potential to introduce decay through the wounds.
Once lifted, special trailers with over 100 wheels are used to distribute the load. Each wheel has a separate hydraulic leveler to keep the tree perfectly level at all times and independent steering to maneuver in difficult places. Large trees may be too wide for roadways or too heavy for bridges and cannot be moved very far. Extremely large trees (up to 500 tons) can be moved with a crawler-transporter.
Box Moving
Trees too large to move B&B can be moved in boxes constructed around a square root ball. First an oversized square root ball is dug with a trencher or backhoe. After final shaping and root pruning with hand tools, the sides of the box are constructed with hardwood planks. Next comes the dangerous phase of digging underneath the root ball to install planks for the bottom. The top of the root ball is sometimes covered with planks. Large boxed trees are usually transported in the upright position because of their great size and weight. Utility wires and light poles may have to be moved and road permits obtained. When the tree is installed, the sides of the box will be removed, but the bottom will remain in place.
Box size
Determining the box size requires consideration of the species, trunk and canopy size, structure and size of roots, and site conditions. Under competitive bidding pressure, tree-moving companies may tend to undersize boxes, putting trees in boxes that are too small. Some tree species may be very sensitive to box size. The recommendation for these sensitive species is to use the largest box possible.
New Technique
A new technique has been developed to move very large trees for short distances.
Pruning
Pruning trees for relocation should be limited. The less foliage removed the less adverse impact on the tree's ability to recover from the transplant shock. Pruning specifications should recommend only the removal of dead or diseased wood.
Fertilization, Supplements
Excellent post-installation care is always part of such a major project. Fertilizers or supplements provide little difference in the survival of relocated trees any time before the tree is established. If the tree is transplanted to a site that is sterile, amendments are beneficial. If the tree is healthy before relocation, there will be a favorable level of nutrients and mycorrhizae in the soil, so transplanting into the same type of soil should be okay.
Usually, amending the backfill for tree installation is not needed. Should a soil analysis reveal toxicity or deficiencies, corrective measures would be appropriate. Consideration must be taken when dealing with soils of different structures since water percolation and irrigation practices will be greatly affected.
Cabling/guy wires
Due to the major root pruning that takes place when moving a large tree, anchorage is compromised. For this reason, all relocated large trees need to be guyed while boxed and before installing the trees. The cables should remain in place for a period of no less than two to five years. Proper cable installation and maintenance not only insures the safety and well being of property and people but also the tree itself.
Installation
The actual installation of relocated trees is usually basic. Backfill is rarely amended unless required to correct specific problems identified by soil analysis. The slight compaction of backfill not only increases stability but also affects irrigation by eliminating air pockets. When large air pockets are present, irrigation has a high probability of seeking out this space and bypassing the root ball. Conduct a percolation test before installation to see if installing a drainage system or soil amendments are needed for the installation hole.
Maintenance and Irrigation
Maintenance and irrigation are critical in the success of relocated trees. If nearly 80% of the tree’s root system is left behind during transplanting, the remaining root zone will be extremely sensitive to soil moisture levels. A fine balance must be found between too wet and too dry. Over watering can occur when the tree is installed too deeply or at the base of a slope; the soil grade has been increased around a tree; irrigation lines are broken; or the site has poor drainage. Under watering occurs when the water does not percolate into the root ball. Soil watering basins or saucers can be used to increase percolation provided they are maintained. The use of irrigation bags around the perimeter of the root ball is highly recommended, because they drip water slowly into the soil and are easily refilled.
Mulching is also very beneficial in aiding the regeneration of root growth. Since newly developing hair roots are highly susceptible to desiccation, mulch helps maintain a moist, cool soil condition conducive to new root growth without constant irrigation.
Pest and Disease Problems
There is an increased susceptibility to pests and diseases associated with the relocation and stress to large specimen trees. These issues can be dealt with by the use of pesticides for the prevention of insects. The most common disease problem encountered is Phytophthora, a root rot usually associated with over-watering. Irrigation management and limited applications of fungicide best achieve control of Phytophthora.
Establishment
The establishment period of large relocated trees varies widely among species and the root/shoot balance. A minimum of two years or longer is required to establish a large transplanted tree, using a standard maintenance program. After two years, maintenance demands are greatly reduced, lessening cost of care. Trees that have been relocated will require some maintenance and monitoring no less than three to four times a year.
Moving large mature trees is a specialty that requires experience and the proper equipment. Start by performing an inspection of the tree and site to determine the likelihood for survival and performance after relocation. The tree must be healthy and vigorous. The tree must be inspected for pests and disease, included bark, girdling roots, as well as cavities and decay. Structural integrity is also important since many trees are relocated to areas where failure is likely. Species must also be considered, as there are several that do not respond well to relocation. Video
Before modern heavy equipment was available to handle the weight of large root balls, trees 15 inches (38 cm) DBH and greater were moved bare root and eventual survival was low. Today large trees are moved with a soil ball that requires extensive knowledge of both arboriculture and heavy equipment. Mature size trees have been moved successfully, but the cost is very high, and it may take decades for larger trees to fully establish at the new site. Root balls can weigh from 100 to 500 tons and crowns can be up to 80 ft (53 m) tall and just as wide. There are very few contractors that specialize and are capable of moving trees of this size. Also, because of the size and weight, very large trees are best moved when the ground is dry or frozen. The rigid boxes and sophisticated lifting systems result in little root ball shifting.
Moving Trees
Special procedures must be used to minimize water stress in large trees. Proper root pruning prior to transplanting can help along with thinning the crown to reduce transpiration. Some contractors install sprinkler heads throughout the crown after installation to cool the foliage and reduce transpiration. Research suggests this practice may be necessary for only a few weeks until new root development begins. Watering and no pruning will be essential during periods of actual drought. The use of treatments to prevent the spread of disease can also be beneficial.
Trees small enough to use typical B&B root ball procedures of 12 in (30 cm) DBH are moved with commonly available tree spades mounted on winch trucks and cranes. The largest tree spade can dig a 14 ft (4.25 m) diameter root ball but because of the difficulty and cost of transporting this machine, it is probably only realistic to use this machine on large jobs with many trees to move.
Cranes are used to lift the largest trees by both the root ball and the branches. Tensions must be even on all cables to avoid damaging branches. Using the sound made by the cable when struck with a hammer to judge cable tension (like tuning a piano string) is an example of the very specialized methods used by experienced contractors. An inexperienced contractor can leave the wrong tension on the cables and that could cause branches to break or cause the tree to separate from its roots.
The method preferred in sandy soils where root balls may break is to lift the tree by one or two heavy steel pins inserted in holes drilled through the trunk. These pins are used to lift the tree in the upright position by both the pins and the root ball at the same time. The drawback of this method is the injury to the trunk, and the potential to introduce decay through the wounds.
Once lifted, special trailers with over 100 wheels are used to distribute the load. Each wheel has a separate hydraulic leveler to keep the tree perfectly level at all times and independent steering to maneuver in difficult places. Large trees may be too wide for roadways or too heavy for bridges and cannot be moved very far. Extremely large trees (up to 500 tons) can be moved with a crawler-transporter.
Box Moving
Trees too large to move B&B can be moved in boxes constructed around a square root ball. First an oversized square root ball is dug with a trencher or backhoe. After final shaping and root pruning with hand tools, the sides of the box are constructed with hardwood planks. Next comes the dangerous phase of digging underneath the root ball to install planks for the bottom. The top of the root ball is sometimes covered with planks. Large boxed trees are usually transported in the upright position because of their great size and weight. Utility wires and light poles may have to be moved and road permits obtained. When the tree is installed, the sides of the box will be removed, but the bottom will remain in place.
Box size
Determining the box size requires consideration of the species, trunk and canopy size, structure and size of roots, and site conditions. Under competitive bidding pressure, tree-moving companies may tend to undersize boxes, putting trees in boxes that are too small. Some tree species may be very sensitive to box size. The recommendation for these sensitive species is to use the largest box possible.
New Technique
A new technique has been developed to move very large trees for short distances.
- Root prune the tree and monitor the health for two months prior to the move.
- Cut a deep trench 30 feet (9 m) long on two sides of the tree and a 30 feet (9 m) long sloping trench on the two opposite sides.
- On one of the sloped sides, use a horizontal boring unit to drill 6 holes, 5 feet (1.9 m) apart underneath the tree’s root ball.
- Then pass a steel cable through the channel to the other side of the root ball and attach it to a 5 ft. wide by 30 feet long sheet of steel, 5/16” (7 cm) thick.
- Attach the cable to a D-8 Caterpillar bulldozer via a cable and pulley system being anchored by a second D-8 bulldozer. The bulldozer will pull the sheets of steel, one at a time under the tree. Repeat this process until all six sheets are under the tree.
- The entire tree is then pulled on this steel sled to its new location where the steel sheets are removed one at a time.
- The tree is then backfilled and maintained, like any new tree installation.
Pruning
Pruning trees for relocation should be limited. The less foliage removed the less adverse impact on the tree's ability to recover from the transplant shock. Pruning specifications should recommend only the removal of dead or diseased wood.
Fertilization, Supplements
Excellent post-installation care is always part of such a major project. Fertilizers or supplements provide little difference in the survival of relocated trees any time before the tree is established. If the tree is transplanted to a site that is sterile, amendments are beneficial. If the tree is healthy before relocation, there will be a favorable level of nutrients and mycorrhizae in the soil, so transplanting into the same type of soil should be okay.
Usually, amending the backfill for tree installation is not needed. Should a soil analysis reveal toxicity or deficiencies, corrective measures would be appropriate. Consideration must be taken when dealing with soils of different structures since water percolation and irrigation practices will be greatly affected.
Cabling/guy wires
Due to the major root pruning that takes place when moving a large tree, anchorage is compromised. For this reason, all relocated large trees need to be guyed while boxed and before installing the trees. The cables should remain in place for a period of no less than two to five years. Proper cable installation and maintenance not only insures the safety and well being of property and people but also the tree itself.
Installation
The actual installation of relocated trees is usually basic. Backfill is rarely amended unless required to correct specific problems identified by soil analysis. The slight compaction of backfill not only increases stability but also affects irrigation by eliminating air pockets. When large air pockets are present, irrigation has a high probability of seeking out this space and bypassing the root ball. Conduct a percolation test before installation to see if installing a drainage system or soil amendments are needed for the installation hole.
Maintenance and Irrigation
Maintenance and irrigation are critical in the success of relocated trees. If nearly 80% of the tree’s root system is left behind during transplanting, the remaining root zone will be extremely sensitive to soil moisture levels. A fine balance must be found between too wet and too dry. Over watering can occur when the tree is installed too deeply or at the base of a slope; the soil grade has been increased around a tree; irrigation lines are broken; or the site has poor drainage. Under watering occurs when the water does not percolate into the root ball. Soil watering basins or saucers can be used to increase percolation provided they are maintained. The use of irrigation bags around the perimeter of the root ball is highly recommended, because they drip water slowly into the soil and are easily refilled.
Mulching is also very beneficial in aiding the regeneration of root growth. Since newly developing hair roots are highly susceptible to desiccation, mulch helps maintain a moist, cool soil condition conducive to new root growth without constant irrigation.
Pest and Disease Problems
There is an increased susceptibility to pests and diseases associated with the relocation and stress to large specimen trees. These issues can be dealt with by the use of pesticides for the prevention of insects. The most common disease problem encountered is Phytophthora, a root rot usually associated with over-watering. Irrigation management and limited applications of fungicide best achieve control of Phytophthora.
Establishment
The establishment period of large relocated trees varies widely among species and the root/shoot balance. A minimum of two years or longer is required to establish a large transplanted tree, using a standard maintenance program. After two years, maintenance demands are greatly reduced, lessening cost of care. Trees that have been relocated will require some maintenance and monitoring no less than three to four times a year.
Installing Palms
Palms are not woody plants. They are not trees. They do not have a cambium and are not capable of generating new tissue to cover injured areas. They are monocots with evergreen leaves coming from a solitary bud. They are more closely related to grass than trees. Due to their tender qualities, efforts must be made to avoid any mechanical damage to the trunks of palms. Terminal buds of palms must be carefully protected from damage, since it is only from this structure that new growth develops. Video
Digging
Palms are often moved with very small soil balls. When the sandy soils are allowed to fall off the roots that do remain, the method might be better described as bare root. For cabbage palms (Sabal palmetto) and other species that regenerate all of their new roots from the base of the trunk instead of the severed root ends, this may be acceptable. Other palms would benefit from more standard root ball procedures. Large multi-stemmed palms may require a ball of 10 to 12 feet (3-4 m) diameter. In California and Arizona, transplanting palms is successful from April to September when the soils are warmer and root development is readily stimulated.
Storage
Palms not immediately reinstalled should be heeled-in like any other plant. Transferring palms to containers is another good way to hold plants. Irrigation and protection from excess sun are important when they are in storage.
Transporting
Some or all palm leaves are often removed prior to transport, rather than waiting to prune them at the planting site. The proper method varies with species and circumstances.
When transporting and handling palms, use care because the bark is easily damaged and damaged areas leave the palm vulnerable to insects and fungus. The best time of year to install palms is during the warmer months when the soil temperature is at least 65º F (19º C).
Palms are lifted in most instances by means of a strap or sling placed just above the estimated balance point on the trunk. The small size and weight of the root ball offers no logical means of lifting by the ball. Nylon slings should be used because they offer a high degree of protection for the palm trunk. When a sling is being attached to the trunk, the surface must be protected from burn or compression marks that will form permanent scars.
When many single stemmed palms are to be transported, they can be laid flat or shingled on a flatbed trailer. The tops should always be tied securely. Transplanted palms with long slender trunks should have a supporting timber attached to its trunk during transport. This important protective support is justified because the alternative is the possible loss of the essential terminal bud and the ultimate death of the palm.
Installing a Palm
Installing a palm is similar to installing other kinds of trees. Nursery-grown palms are generally sold either potted or B&B. Dig a hole wide enough to fit the root ball with plenty of room to spare. The hole should be twice as wide as the ball diameter. The hole should be just deep enough so that the palm is installed at the depth at which it was grown in the nursery or 1” higher. Do not install the palm any deeper as this may deprive the roots of nutrients and water. The backfill soil should be the same soil as excavated for the installation site.
When the palm has been installed, build a basin with soil around the circumference of the hole to form a saucer that will hold water. Then lay down a layer of organic mulch around the palm about three inches deep.
Root Development
It is commonly believed that if the tube-like roots of palms are cut during the digging process they will usually die back and new roots will originate from the root initiation zone at the base of the trunk. Actually, growth response of severed palm roots varies with species and distance from the base of the trunk. Less than 1% of all cut cabbage palm (Sabal palmetto) roots regenerate root tips, whereas coconut palms (Cocos nucifera) regenerated root tips about 50% of the time regardless of root stub length. Queen (Syagrus romanzoffianum) and royal palms (Roystonea sp.) regenerated more new root tips as the length of the root stub was increased. Root pruning stimulates new roots from the root initiation zone for all species, but at a rate inversely proportional to the ability of the species to regenerate root tips on severed roots.
Palm roots emerge from the trunk at a root initiation zone located at a swelling at the base of the trunk. Palms that are installed too deeply have no swelling.
Watering
Frequent watering is crucial for newly installed palms. Water daily for about the first two weeks after installation and then tapering off over several months as the palm establishes itself. Use irrigation to soak the area around the palm very slowly. It is important to not allow the soil to dry out, as this will severely weaken the new palm.
Fertilizer
Palms also require periodic fertilizer applications. There are commercial mixes available especially for palms.
Pruning
In the past, it has been common practice to remove 2/3 or more off the leaves of palms before transplanting. Recent research has indicated that with regular irrigation, palm quality and root growth was increased as the maximum number of leaves was retained. The practice of tying the leaves into a bundle to protect the bud from drying during a drought has been found to have no positive effect and could actually lead to fungal infection in the bud if irrigation or rainfall were frequent.
A current recommendation is to remove no more than 1/3 of the leaves if the plant is moved with a small root ball. It is not necessary to remove any leaves of palms grown in containers or moved with a tree spade. If irrigation is ample, the leaves do not need to be removed on any palm regardless of the installation method. If leaves are pruned off before moving, the tree does not need to have additional leaves removed at the installation site.
Note:The mention of product names throughout this entire topic does not constitute an endorsement of these products. They are mentioned only for providing the reader with useful information.
Sources
The test that follows contains 80 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 4.0 CEUs* for a passing grade. SAF members will earn 1.0 Cat. 1-CT credit for a passing grade. The cost for taking this test is $20 per credit. 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. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 4.0 CEUs toward Certified Arborist, Tree Worker Specialist, Utility Specialist, Municipal Specialist, Aerial Lift 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 and MTOA members may submit your ISA certification record to these organizations and receive credits one for one.
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.
Palms are not woody plants. They are not trees. They do not have a cambium and are not capable of generating new tissue to cover injured areas. They are monocots with evergreen leaves coming from a solitary bud. They are more closely related to grass than trees. Due to their tender qualities, efforts must be made to avoid any mechanical damage to the trunks of palms. Terminal buds of palms must be carefully protected from damage, since it is only from this structure that new growth develops. Video
Digging
Palms are often moved with very small soil balls. When the sandy soils are allowed to fall off the roots that do remain, the method might be better described as bare root. For cabbage palms (Sabal palmetto) and other species that regenerate all of their new roots from the base of the trunk instead of the severed root ends, this may be acceptable. Other palms would benefit from more standard root ball procedures. Large multi-stemmed palms may require a ball of 10 to 12 feet (3-4 m) diameter. In California and Arizona, transplanting palms is successful from April to September when the soils are warmer and root development is readily stimulated.
Storage
Palms not immediately reinstalled should be heeled-in like any other plant. Transferring palms to containers is another good way to hold plants. Irrigation and protection from excess sun are important when they are in storage.
Transporting
Some or all palm leaves are often removed prior to transport, rather than waiting to prune them at the planting site. The proper method varies with species and circumstances.
When transporting and handling palms, use care because the bark is easily damaged and damaged areas leave the palm vulnerable to insects and fungus. The best time of year to install palms is during the warmer months when the soil temperature is at least 65º F (19º C).
Palms are lifted in most instances by means of a strap or sling placed just above the estimated balance point on the trunk. The small size and weight of the root ball offers no logical means of lifting by the ball. Nylon slings should be used because they offer a high degree of protection for the palm trunk. When a sling is being attached to the trunk, the surface must be protected from burn or compression marks that will form permanent scars.
When many single stemmed palms are to be transported, they can be laid flat or shingled on a flatbed trailer. The tops should always be tied securely. Transplanted palms with long slender trunks should have a supporting timber attached to its trunk during transport. This important protective support is justified because the alternative is the possible loss of the essential terminal bud and the ultimate death of the palm.
Installing a Palm
Installing a palm is similar to installing other kinds of trees. Nursery-grown palms are generally sold either potted or B&B. Dig a hole wide enough to fit the root ball with plenty of room to spare. The hole should be twice as wide as the ball diameter. The hole should be just deep enough so that the palm is installed at the depth at which it was grown in the nursery or 1” higher. Do not install the palm any deeper as this may deprive the roots of nutrients and water. The backfill soil should be the same soil as excavated for the installation site.
When the palm has been installed, build a basin with soil around the circumference of the hole to form a saucer that will hold water. Then lay down a layer of organic mulch around the palm about three inches deep.
Root Development
It is commonly believed that if the tube-like roots of palms are cut during the digging process they will usually die back and new roots will originate from the root initiation zone at the base of the trunk. Actually, growth response of severed palm roots varies with species and distance from the base of the trunk. Less than 1% of all cut cabbage palm (Sabal palmetto) roots regenerate root tips, whereas coconut palms (Cocos nucifera) regenerated root tips about 50% of the time regardless of root stub length. Queen (Syagrus romanzoffianum) and royal palms (Roystonea sp.) regenerated more new root tips as the length of the root stub was increased. Root pruning stimulates new roots from the root initiation zone for all species, but at a rate inversely proportional to the ability of the species to regenerate root tips on severed roots.
Palm roots emerge from the trunk at a root initiation zone located at a swelling at the base of the trunk. Palms that are installed too deeply have no swelling.
Watering
Frequent watering is crucial for newly installed palms. Water daily for about the first two weeks after installation and then tapering off over several months as the palm establishes itself. Use irrigation to soak the area around the palm very slowly. It is important to not allow the soil to dry out, as this will severely weaken the new palm.
Fertilizer
Palms also require periodic fertilizer applications. There are commercial mixes available especially for palms.
Pruning
In the past, it has been common practice to remove 2/3 or more off the leaves of palms before transplanting. Recent research has indicated that with regular irrigation, palm quality and root growth was increased as the maximum number of leaves was retained. The practice of tying the leaves into a bundle to protect the bud from drying during a drought has been found to have no positive effect and could actually lead to fungal infection in the bud if irrigation or rainfall were frequent.
A current recommendation is to remove no more than 1/3 of the leaves if the plant is moved with a small root ball. It is not necessary to remove any leaves of palms grown in containers or moved with a tree spade. If irrigation is ample, the leaves do not need to be removed on any palm regardless of the installation method. If leaves are pruned off before moving, the tree does not need to have additional leaves removed at the installation site.
Note:The mention of product names throughout this entire topic does not constitute an endorsement of these products. They are mentioned only for providing the reader with useful information.
Sources
- Appleton, Bonnie, "Basic Tree Biology", City Trees, The Journal of The Society of Municipal Arborists Vol. 37, Number 6 November/December 2001
- Appleton, Bonnie, "Trees for Parking Lots and Paved Areas", Publication Number 430-028, Virginia Tech, March 2002
- Brohn, Paul D., "Bare Root Street Tree Planting", City Trees, The Journal of The Society of Municipal Arborists Vol. 37, No. 4 July/August 2001
- Buckstrup, Michelle J & Nina L Bassuk, "Transplanting B&B VS. BR", Journal of Arboriculture 26(6): 298-308
- Clatterbuck. Wayne K. "Post-Planting Tree Care: Fallacies and Recommendations", Agricultural Extension Service The University of Tennessee
- Coder, Kim, "Training Young Trees", For96-35, University of Georgia Cooperative Extension Service Forest Resources Unit 1996
- Costello, Larry, "Training Young Trees", City Trees, The Journal of The Society of Municipal Arborists, Vol. 37, Number 6, November/December 2001
- Davis, Todd, "Right In Line", Nursery Management & Production, December 2003 p. 22-26
- DeGaetano, Arthur T., "Urban Tree Containers", Journal Of Arboriculture, 26(3): 142-151
- Doherty, Karen, David V. Bloniarz and H. Dennis P. Ryan, "Positively the Pits! Successful Strategies
for Sustainable Streetscapes", TCI Magazine - November 2003 - Ferrini, F. et al, "Establish Trees in Urban Sites", Journal of Arboriculture 26(5): 281-284
- Gilman, Edward F. "Establishing Trees in the Landscape". The Landscape below Ground: Proceedings, International Society of Arboriculture, 1994.
- Gilman, Edward F. "Fabric container grown Trees", ENH870, Environmental Horticulture Department, University of Florida
- Gilman, Edward F., "Planting Trees in Landscapes", Environmental Horticulture Department, IFAS,
University of Florida, 2004 - Himelick, E.B., "Tree and Shrub Transplanting Manual", International Society of Arboriculture, 1991.
- Howland, Rick, "Long-Lived Tree Spades...Contribute to Long-Lived Trees", TCI Magazine, November 2002
- Iles, Jeff, "Innovative Container Production Systems for Growing Better Trees", City Trees, the Journal of the Society of Municipal Arborists. Vol. 37, Number 2, March/April 2001
- Iles, Jeff, "Tree Planting Basics", 1997
- Jacobs, Bernard, FASLA and Terry Warriner Ryan, FASLA, "The Root of the Matter", Landscape Architecture, November 2003
- Johnson, Gary R., "Buried Root Systems and Tree Health", Department of Forest Resources, University of Minnesota, 1995
- McCoy, Miles, "Containers: The nursery industry's changing production tool", Nursery News, Vol. 19 No. 3, March 2004
- Neely, Dan, and Gary Watson, "The Landscape below Ground II", International Society of Arboriculture, 1998.
- Norman, Kerry, "Tree Moving with Success", TCI Magazine, June 2003
- The Northern Illinois Specification Review Committee, “Guidelines for Growing, Installing and Maintaining Healthy Trees”, Illinois Green Industry Association, 2012.
- Powell, Charles C. "How to Water Plants", NM/PRO, March 2004.
- Tilt, Ken, et al, "Bare Root ShadeTree Liner Production in Containers", SNA Research Conference, Ornamental Horticulture Substation, Vol. 45, 2000
- TreeHelp Ltd., “Planting a Palm Tree”,
- Tree Moving", Landscape Management, April 2002
- Trowbridge, Peter J. and Nina L. Bassuk, "Trees in the Urban Landscape", John Wiley &
Sons, Inc. 2004. - Watson, Gary W. and E. B. Himelick, "Principals and Practice of Planting Trees and Shrubs"', International Society of Arboriculture, Savoy, IL 1997
- Watson, G. and Dan Neely, "The Landscape below Ground", International Society of Arboriculture, 1993.
- Whitcomb, PhD, Carl E, "Optimal Tree Growth", The Master Plantsman, Issue 2
- Foti, Matt, "Bare Root Planting with an Air-Spade®”, New England Grows lecture. 2011.
- Howe, Deborah, "Another air-tool bare-root transplanting", Taking Place, July 29, 2009.
- Howe, Deborah, "Roots First", American Nurseryman, December 2008.
The test that follows contains 80 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 4.0 CEUs* for a passing grade. SAF members will earn 1.0 Cat. 1-CT credit for a passing grade. The cost for taking this test is $20 per credit. 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. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 4.0 CEUs toward Certified Arborist, Tree Worker Specialist, Utility Specialist, Municipal Specialist, Aerial Lift 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 and MTOA members may submit your ISA certification record to these organizations and receive credits one for one.
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.