Trees & Shrubs
Helping Nebraskans enhance their lives through research-based education.
Tackling Tree Roots at the Surface
by Don Janssen, UNL Extension Educator
Much to the dismay of homeowners, landscape trees sometimes grow roots on top of the surface of the lawn, or possibly even buckle sidewalks and driveways (photo above). These surface roots can be quite a nuisance to lawn mowers and running feet.
There are several reasons why the roots come to the surface. Some tree species seem to be more prone to surface roots than others, most notably silver maple, poplar and willow. But almost any large, older tree will produce some surface roots. The notorious species are likely just fast- growing species that bring the problem to the surface faster than others.
Although trees do send some roots down deep for moisture and stability, most tree roots tend to grow much more shallowly than most people think--usually only 4-8 inches deep. Just as the trunk of the tree grows in diameter with age, so do the roots. So over time, some of the shallow, older roots of the tree will naturally enlarge to the surface. Sometimes, roots become visible due to erosion of the surface soil.
Once the roots appear on the surface, there is little that can be done to remedy the situation, without substantially damaging the tree. You can prune off the visible roots, but the damage to the cut roots and the fine feeder roots surrounding the area can harm, or even kill the tree. Pruning the roots should be confined to situations where the roots are breaking up sidewalks or driveways. Some homeowners have tried a temporary solution by applying a shallow, 1-inch layer of good-quality soil mix and then replanting the grass. However, it isn't long before roots will reappear as they continue to grow in diameter.
Some trees are very sensitive to changes in grade level, so more than an inch of soil risks harming the tree. A more permanent solution would be to replant the affected surface area with a taller ground-cover type plant that will not need mowing.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office
Contact InformationUniversity of Nebraska-Lincoln
in Lancaster County
Web site: lancaster.unl.edu
444 Cherrycreek Road, Suite A,
Lincoln, NE 68528