The root system of a tree should also be inspected. A healthy root system has many fibrous, or smaller, white cream colored roots and larger brown roots. A healthy root system is one of the key aspects of tree health, and if it is discovered that the plant you selected does not have one, it should not be purchased.
Root systems should also have a good arrangement. Excessive number of broken roots, roots wrapped around the trunk, or roots growing in odd directions can lead to the decline of the tree as it ages.
Balled and Burlapped Problems |
It is important that the soil ball is big enough for the size of the tree. ANSI has standards for balled and burlapped soil ball heights and diameter.
The size of the ball is determined by the diameter of the trunk just above the root system, referred to as caliper. As a general rule it's 11 inches of soil to 1 inch of caliper.
To the right, ANSI soil ball specifications on ball 24 inches tall are being checked. |
|
| Here they are checking ANSI specifications for ball 30 inches wide. This is done by measuring the diameter of the ball.
Most nurseries only sell stock that meets ANSI minimum soil ball size standards, but still be on the look out for balls that do not seem to fit the size of the tree. |
|
| This is an example of a soil ball falling apart due to exposure. This ball was dug the previous year.
Ideally the soil ball should be in tact, with only one layer of wrap. Multiple layers can be a sign that the plant had been sitting around for a long time and the initial burlap layer and begun to disintegrate. |
|
For B&B and container trees the first order roots should be at the surface of the soil. Often, this is not the case. Due to various propagation and growing techniques the roots can be buried 4" or more under the surface. This greatly reduces the amount of roots that come with the tree, limiting it growth, and significantly shortening its life. Another side effect of a buried root system is Stem Girdling Roots (SGR). Please see the SGR section for more information. The following slides show a tree that should not be planted. |
| This tree is a demonstration tree. Please do not take apart the soil balls or trees before purchase.
The white paint on the trunk marks the top of soil ball. |
|
| The ball is taken apart and the loose soil over trunk flare is removed. |
|
| Note the distance from top of burlap to first order roots of this tree. |
|
| This is another example of a tree planted too deep and dug with an inadequate root system. Do NOT plant this tree. |
|
| This is a non-destructive way to find the first order roots. Use a surveyor's pin or piece of wire to probe for the roots. With this method the burlap does not have to be removed. This can be done at the nursery. |
|
| Container Problems |
| Container trees should also be inspected for depth to the first order roots.
This can be done with a spade or with a surveyor's pin. |
|
Another concern of container trees is that they are pot bound. Roots of a plant should not be wrapped around the edge of the soil ball. A deformed root system like this can cause poor nutrient uptake and decline in the tree. It can also cause Stem Girdling Roots, please see the SGR section for further explanation. |
| How to check the rooting pattern of container plant, looking for roots encircling the surface of the soil.
Hold the tree by the main stem and push down on the container. |
|
| The container should come off with out too much effort. Pull the plant out of the container and place on the ground. |
|
| Note the white and orange colored roots encircling the surface of the soil. Even though they are very healthy roots, they will eventually bind up the root system, and the plant will be unable to find nutrients. |
|
| This is an example of a container tree that was pot bound and "growing" in the field. The tree declined in the field and when it died the root system was dug up, this was found. |
|
| Another problem of container trees are roots that hit the side of the container and turn back, forming tangential roots. The tangential roots can lead to the development of stem girdling roots. |
|
| One way to determine if a plant may have encircling roots it to determine how long the plant has been in the pot. If there are lot of other plants growing in the pot with the tree of interest, it has probably been in the pot too long. |
|
| This is the same plant as above. Note how it does have encircling roots that could disrupt normal functioning of the root system. |
|
