Tree Surface Roots: Should I Remove or Cover with Soil

Published April 15, 2011 By KEVIN BASSETT

Surface roots in the lawn can be a big nuisance. Nevertheless, there are a number of ways to address them successfully. It is important to understand that a healthy tree root system is vital to a tree’s health. Roots perform a number of fundamental functions including the absorption of water and nutrients, transport of those raw materials, anchorage of the tree, and storage of energy that can be utilized when needed.

Arborilogical Services, Inc. encourages practices that prevent or minimize injury to roots. Cuts to the root system can open entrance courts for root diseases. The loss of root area can have a devastating impact on tree health. Yet in many ways, the removal of a problematic root is much the same as the removal of a limb or a branch.

It is important to consider how many roots are to be removed. One or two small surface roots removed correctly will probably not affect a tree’s general health. However, damage or removal of 25% of the root area can have devastating results.

Pruning roots slightly before or during our hot summer months should be avoided. The demand a tree places on its root system is highest during these months and root regeneration is less likely. If roots must be removed, fall and winter months are best. Finally, when roots must be cut, they should be cut in a clean, sharp manner.  Jagged, torn, and ripped roots will not regenerate new roots nearly as well as roots with a precise cut.

Covering surface roots is another possible option. This is preferred in many situations if the roots have been exposed by soil erosion. Root areas may be covered with two to four inches of quality, loose topsoil. Some potential drawbacks need to be considered. Adding soil may create drainage problems. Adding too much soil can deprive the roots of the oxygen needed for normal function.

Often the best solution is to leave the surface roots and convert the turf area to an appropriate ground cover. Turf and trees is seldom a good match. Thinning turf and turf loss under trees are very common since turf is a prairie plant. There is an inherent conflict when we try to grow one under the other. Many trees are seriously damaged by over-thinning and removing large, low limbs to gain more light for the turf.

Your consulting arborist can evaluate your tree's situation. Potential solutions and a plan can be developed to help address surface roots. Be very careful when doing anything that could impact the roots, they are vital to tree health.

Learn more about trees and their root systems on our website, and by reading the article "The Dangers of Root Disturbance" in our Article Library.