Most property owners are aware that trimming and fertilizing of the trees on their properties are essential for maintaining optimum tree health. What most people don’t know is that tree roots can circle, or “girdle,” the base of the tree trunk. Root girdling impedes the tree from receiving necessary nutrients from the soil through the root system. The remedy to root girdling is root crown excavation. To ascertain whether a tree needs root crown excavation, the property owner must call a certified arborist.
Trees are such a vital part of landscaping that maintaining their health should be of utmost important to the property owner. Trees provide shade, oxygen, beauty, wildlife refuge, and depending on the variety, food for both humans and animals. Property values increase when there are beautiful, healthy trees on it.
The Root System
A tree’s root system is the most vital part of the tree. It is through the root system that the tree receives nutrients, oxygen, and water. These components are most readily available near the surface of the soil. The healthy large tree’s root system is approximately 18″ to 24″ from the soil’s surface. The tiny, absorbing roots grow especially close to the surface.
The root system can spread, under ideal roomy conditions, as much as two or three times farther out than the limbs, although some have been known to spread as far as between two and three times the height of the tree. A tree’s root system also provides structural stability and support, synthesizes hormones, and stores food. Therefore, it is imperative to inspect the trees on a regular basis to ensure that each tree has a healthy root system.
What Causes Root Girdling
Root girdling can be caused by a couple of different things. One is that the tree was planted too deeply. If the tree “stovepipes” into the ground, meaning the trunk goes straight into the ground with no roots showing, it is buried too deep. Another thing that causes root girdling is adding topsoil around the tree covering the root flare. When soil is placed around the trunk of the tree it can cause serious damage over time. The bark and cambium layer, and the root flare, will decay, resulting in the death of the tree. The trunk of the tree can’t tolerate being constantly in damp soil like the root flare can. It will eventually decay.
There is a balance that must be achieved between having the roots exposed too much above ground and being buried too deep to thrive. Knowing what this balance is will help the tree owner to keep the tree at optimum health.
Professional Root Crown Excavation
When the property owner suspects his trees are not healthy, he should call a Certified Arborist to come out and inspect the trees in question. A professional arborist can determine what is wrong with the tree, and then perform the necessary procedure to try to save the tree from dying. This process is known as root crown excavation and should only be performed by a certified arborist.
An amateur tree worker doesn’t have the training necessary for determining root girdling, nor for the delicate process of root crown excavation. That is a process that should be left to a professional. Left to an inexperienced person, the task of root crown excavation can easily damage the tree roots resulting in the death of the tree. Often the decline and death of the tree won’t be noticeable for years, so the tree owner will likely have no idea of what caused the tree to die.
Signs of Root Girdling
How does a person know if the tree is experiencing root girdling, or other problems with its root system? A few signs to look for are: tree bark wounds that “bleed;” depressed areas around the root crown; loose, peeling bark around the flare; adventitious and girdling roots growing above the flare. Other symptoms can include poor growth in the crown, thinning, defoliation, crown dieback, or chlorosis of the foliage.
On the other hand crown symptoms don’t always indicate root problems. It could be that the tree has vascular issues. Healthy roots are usually white or light in color when the bark is peeling back. Rotting roots are dark brown or black and have loose, peeling bark.
Root Crown Excavation
The process of root crown excavation is a delicate and time consuming undertaking. The small roots near the surface are easily damaged, so great care must be taken to not harm them. Arborists have a special instrument that forces air in through a hole when a plug of soil has been removed for the sole purpose of root crown excavation. This breaks up the hard, compressed dirt around the tree, making soil removal possible without damaging the roots.
The soil is then gently removed from about the roots, taking great pains to ensure that nothing is done to damage the delicate roots. When sufficient soil has been removed from around the tree’s roots, the roots will have room to grow, to receive nourishment from the soil, and regain their health.
Caring for the trees on the property owner’s land is so important for a number of reasons. One is that it is even more costly to have to have a tree cut down, the stump removed, and a new tree planted in its place, than it is to care for the ones already growing on the property. Tree maintenance is an expense, but if the owner has regard for the trees on his property, it is something that will be taken in stride, just as is building maintenance. Tree inspections should be conducted at regular intervals, looking for signs of root girdling or decay, such as were mentioned earlier. Winter is the best time to do this inspection, so that if root crown excavation needs to take place, it will be when the tree is in its dormant stage.