Tree Pruning

How to Start

Pruning is done when the tree is several years old and branches are not too large. A good pruning when the tree is young reduces problems when it is mature. The tree has a natural defense system that will seal the pruning cuts but only if they are done properly. When the tree is young and the branches are small, they seal quicker.

Pruning places stress on a tree and should only be done when necessary. Before you prune, step back and take a good look at the tree. Does it actually need pruning? If so, what needs to be done? You can remove dead or dying limbs, crossing limbs, limbs growing in the wrong direction or too high, co-dominate leaders and v-shaped crotches. You should keep the natural shape of the tree and you should never remove more than 25% of the crown. Your goal is to have a strong trunk and well-spaced branches.

A Roanoke Tree Steward Prunes a Tree

A pruned tree is safer, will live longer and will increase property values. An unpruned or poorly pruned tree is a safety hazard. Pruning can be confused with tree topping. While pruning is good, tree topping is bad.

If You Need a Professional

If you are pruning high branches or heavy branches, have to climb the tree or need to use a chainsaw, you should call a professional instead of doing the work yourself. Find a Certified Arborist in your area. If the tree is near valuable property or if power lines are involved, you also need a professional. You must not allow people, equipment or tree branches to touch utility lines. American Electric Power can help you with trees under utility lines along the street in front of your property. You can call AEP Customer Solutions Center at 1-800-956-4237.

Time to Prune

If you plan to prune the tree yourself, you first need to learn the importance of the branch collar. It contains tissue of both the tree and the branch. It appears as a raised area where the branch connects to the tree. You should never cut into the branch collar. That would expose the tree to disease and insects. The branch collar has the natural power to seal correct pruning cuts. You should cut a branch outside the branch collar and without leaving a stub.

Graphic: International Society of Arboriculture

For most trees, you will be pruning in late winter or early spring (before growth begins). The wound is less likely to be bothered by insects, disease and fungi when the cut is made in the dormant season. Dead branches can be pruned at any time. Lower limbs can be removed for head clearance when

they are 1" in diameter. Try not to prune branches more than 4" in diameter because the wounds take so long to seal.

Graphic: USDA Forest Service

If the branch is less than 1" in diameter and you can support it with one hand while cutting, you can simply cut it off just outside the branch collar. If the branch is larger than that, you will need to use the 3-cut method to avoid tearing the bark. First you will make an undercut about 4" away from the branch collar. Cut up into the branch about 1/3 of the way through. Second, you will move an inch or two further out on the branch and cut all the way through the branch from above. Third, cut off the remaining stub just outside the branch collar.

For More Information

Check out this animated Tree Pruning Guide from the Arbor Day Foundation. For further information, visit the USDA Forest Service, Virginia Cooperative Extension and International Society of Arboriculture (young trees or mature trees) websites.