Much to the dismay of homeowners, landscape trees sometimes grow roots above the surface of the lawn. These 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. Sometimes roots become visible due to erosion of the surface soil. But almost any large, older tree, such as those grown to shade large homes, will produce some surface roots.
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 to 8 inches deep. Just as the trunk of the tree grows in girth with age, so do the roots. So over time, some of the shallow feeder roots of the tree will naturally enlarge to the surface.
Once the roots appear, 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.
As a temporary solution, you could apply a shallow, 1- to 2-inch layer of good quality soil mix, then replant the grass. However, it won’t be long before roots reappear. If feasible, replant the area with a taller ground cover type plant that will not need mowing.
The best remedy for surface roots is to choose the proper plants for the situation. But if you already have a large old tree with surface roots that you don’t want to lose, you may just have to learn to accept its intrusion into the lawn.