Trimmers and Tree Ties Can Damge Trees

I use a line trimmer to trim the grass around my trees. My neighbor says I am damaging my trees. Is that true?

Power line trimmers or weed eaters have become one of the most popular gardening tools. Almost everyone has one. Whether powered by electricity or gas, they quickly trim and edge lawns, and cut grass and weeds in areas which are difficult to reach with mowers. They create a neat, tidy look which is very appealing.

One of their more popular uses is to trim grass and weeds growing around trees. An occasional use around a well-established tree probably does little damage. However, weekly use around trees, especially young ones, is devastating. Every time the line hits the bark of a tree, a little outer bark is removed. As fast as line trimmers rotate, that may be a hundred times in one trimming. After 20 or 30 trimmings, there may be little or no bark left.

The inner bark of a tree contains the tubes which carry food manufactured by the leaves down to the roots. If some of these tubes are damaged, less food reaches the roots. Slowing root growth means the tree can support fewer leaves. This reduces the growth rate and can actually reduce tree size as leaves are shed to balance top growth with root capacity. Once all the conducting tubes are cut, no more food reaches the roots and they begin to die. A slow, painful death of the leaves and branches follows.

Tree ties attached to stakes to support newly planted trees can also be damaging. If they rub as the tree moves, or are applied too tightly, or are left on too long, they can also cut into and damage the bark where they are attached. Even if applied properly, they can also damage the bark as the trunk grows in diameter. In most cases, stakes and ties should be removed after one growing season.


Allen Wilson

Allen has been writing about gardening for over 30 years. He is a retired professor of Horticulture.

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