Correctly trimming trees and proper tree pruning techniques are part art and part science. Once you know some of the science behind it, you can trust your eye for the artistic elements of pruning. Then, take a deep breath and start making your cuts.

Tree Trimming Safety

Approach every pruning situation by assessing the need for a professional arborist. Then, leave these tasks to the professionals with the equipment and advanced training for tricky pruning jobs.

Tree trimming near power lines.Removal of large dead or dangling branches.Big branches near homes or buildings.

When to Prune Trees

Late fall and early winter are the best times to prune deciduous trees (most evergreen trees should be lightly pruned in late winter). The bare branches allow you to see the tree structure clearly. Avoid major pruning during “maple sugar time” (January through early March in most areas). Beetles that attack oak trees are active from late spring through midsummer. If oak wilt is present in your region, don’t prune your oaks during this period. Prune away dead or diseased branches whenever you notice them. Waiting until fall or winter to prune these branches could cause further tree damage or infection in the case of diseased branches. (When pruning diseased branches, dip the pruning blade in a 10 percent bleach solution between each cut to avoid spreading disease.)

How to Cut Large Branches

Larger branches are best removed in three steps:

Make a shallow cut on the underside of the branch, about 4-5 inches from the trunk.Cut the branch off about 2-3 inches from the initial cut. When the weight of the unsupported branch causes it to fall, the initial cut keeps the bark from peeling down the side of the trunk.Make the final cut, removing the remaining stub. Make this cut just outside the branch collar: the slightly swollen area where the branch and trunk are joined together.

Tips for Tree Pruning Challenges

Natural growth patterns, storm damage, and specific landscape needs can create unique tree pruning challenges. Here are the most common situations you may encounter and how best to handle them. Native elms, hornbeams, serviceberries, hickories, and Osage orange trees are generally strong enough or small enough that little corrective pruning is needed for structural purposes, except to remove crossing branches that might rub. Other trees, particularly maples, flowering pears, ashes, willows, and basswoods, should be watched closely and given early training to avoid structural problems as they grow larger. Narrow, V-shape junctures are inherently weak and are subject to breaking off in wind or ice storms. To prevent V-shapes from causing problems, remove one of the stems while the tree is young. The following is a list of trees that tend to form V-shape junctures:

Basswoods (Tilia spp.) Elm (Ulmus spp.) Flowering pear (Pyrus calleryana) Hackberry (Celtis spp.) Hornbeam (Ostrya spp. and Carpinus spp.) Locust (Gleditsia spp. and Robinia spp.) Mulberry (Morus spp.) Osage orange (Maclura pomifera) Redbud (Cercis spp.) Serviceberry (Amelanchier spp.) Some ashes (Fraxinus spp.) Some hickories (e.g., Carya cordiformis) Some maples (e.g., Acer saccharum, A. saccharinum) Willow (Salix spp.) Zelkova (Zelkova spp.)

The best way to avoid annual suckering challenges is to avoid planting trees that commonly produce suckers. A reputable nursery or landscaper will be a great help. To prevent this, remove one of the forked trunks while the tree is still young. Cut as close to ground level as possible, making the cut at a slight angle, so rainwater drains off the stump. Take care not to damage the bark on the remaining trunk. Most arborists now use tarlike wound dressings only for special purposes. For example, some insecticidal wound applications might be used to discourage beetles from visiting and possibly spreading oak wilt disease.