Tree shoots are sprouts that grow from the roots of a larger tree or shrub. You will usually find them several inches to many feet from the base of the parent tree. These root sprouts are somewhat different from the shoots that grow from the base or trunk of the tree; these sprouts are called "suckers", and they are weak structures that should be removed as they appear. They will not grow into strong branches nor strong new trunks. They will only drain energy from the parent plant.
Root shoots, on the other hand, can grow into strong, healthy replacement trees. This is both good and bad. It is good in the case of short-lived trees or trees that are prone to insect and disease problems, such as aspen. If the parent tree begins to die, often the root shoots will provide a free replacement. (Remember, however, the replacements will be susceptible to the same problems.) Or if you want more trees in your yard, you can simply grow them from the shoots.
However, while the parent tree is young and healthy, and if you don't want more trees, the root shoots become the equivalent of a weed in the lawn. So what can you do about them when they are a pest? That is part of the bad news; there are no good ways to prevent the growth of these root sprouts. And there are not even any good ways to get rid of them. If they are a severe problem for you, you may want to consider replacing the tree or shrub with a variety that does not have the problem. Nurseries and horticultural specialists can recommend varieties that do not give rise to root shoots.
Certain herbicides will also kill roots shoots, but extreme care must be taken when using this method because the herbicide can sometimes travel through the root and into the parent tree, causing permanent damage or even death. Glyphosate (or Roundup as it is commonly known), and 2,4-D are two examples of this type of herbicide. Herbicides will travel varying distances, and under certain conditions can sometimes be used to kill shoots that are a long distance from the parent tree. To prevent damage or tree death, it is best to get advice from an herbicide specialist before you use this method.
Professional lawn care companies can apply products containing maleic hydrazide, such as Maintain A or Royal Slo-Gro, to fresh-cut shoots to inhibit subsequent regrowth, but these products are not available to homeowners unless they are licensed pesticide applicators. However, landscape maintenance companies in your area should be able to obtain and apply them for you.
Handbook of Integrated Pest Management for Turf and Ornamentals. 1994. Leslie, A.R., ed. U.S. Environmental Protection Agency. Lewis Pub., Boca Raton, FL. 660 pp.
Written by Sherry Lajeunesse, Extension Urban Pest Management Specialist. Sept., 1997