Lateral Pruning Method

KUB contractors use the lateral pruning method recommended by the Arbor Day Foundation, International Society of Arboriculture, and National Arborist Association. Lateral pruning removes branches where they meet the closest lateral branch that is at least one-third the diameter of the original branch and that grows away from the electric line. (If there is no lateral branch to prune to, however, the limb must be removed at the tree's trunk.) That leaves a healthier tree with no stub to decay and prevents the growth of weak sprouts.

Proper pruning may mean removing branches beyond the required minimum 10 feet of clearance for distribution lines or 25 feet for transmission lines. If the closest proper-size lateral branch is farther away than the minimum clearance, the extra pruning is healthier for the tree.

By directing growth away from electric lines, lateral pruning results in less future pruning. That reduces the visual impact and the cost of pruning. Holding pruning costs down helps save customers money in the long run.

In the past, trees were commonly pruned by topping or "rounding over." Research shows that encourages wood decay in the large remaining stubs and promotes unhealthy sprouting around the stubs.

The sprouts from "rounding over" also grow much faster than normal growth. As an example, Silver Maple (the most common tree found growing under KUB electric lines) normally grows about two feet per year. The sprouts induced by "rounding over," however, average more than six feet per year. The sprouts also grow faster than their attachment to the stub, creating weak branches that are more likely to break than normal growth.

 

Please be advised that cable, phone, city, county, state or other agencies may also be pruning and clearing their own right-of-way sections in your area. Those agencies may use pruning methods and guidelines different from the Arbor Day Foundation/Tree Line USA-approved standards followed by KUB. You can confirm whether or not KUB tree pruning contractors are currently working in your area by visiting our on-line Vegetation Management map , calling the Vegetation Management Hotline at (865) 558-6658 Monday through Friday, 7 a.m. - 9 p.m., or contacting us via email at trees@kub.org .

For more information regarding effective and healthy tree pruning methods, visit the Arbor Day Foundation .