Pruning Your Trees and Shrubs

Whether you want to restore a mature tree, create a distinctive shape, remove damaged or diseased limbs or reduce the weight of branches hanging over homes, roads or sidewalks, pruning is an important tool. How and where you make your pruning cuts can have a significant impact on how trees and shrubs heal and develop in future years. Understanding a little bit of the science behind how plants grow and respond to pruning cuts can help you achieve your goals with confidence.

Most pruning is done to maintain or improve a tree’s health, structure and appearance. Proper pruning can increase air circulation, sunlight penetration and reduce stress on limbs due to wind, snow or ice. In addition, properly pruned trees are less likely to be harmed by insects or disease.

A common goal of pruning is to establish good scaffold branches, the primary limbs that form a tree’s canopy. This is usually accomplished by removing dead, damaged or diseased limbs, thinning out branches that cross or touch each other, removing narrow crotches and reducing the overall size of the crown.

While establishing a good framework is an essential goal of pruning, many homeowners also want to shape their property’s landscape by adding height or depth to the planting area. To do so, you’ll need to prune the main trunk of the plant and its large lateral branches. This is called crown thinning and is typically done to open up the interior of the canopy, reduce weight on limbs and branches and improve light penetration to the ground.

The best time to prune deciduous trees and most evergreens is late winter or early spring, before new growth begins. This is when plants are most easily managed without their leaves, and pests and diseases are at their lowest level. However, some berries-producing ornamental trees and shrubs (like holly and pyracantha) should be pruned in summer or early fall to avoid removing potential berry buds.

Some fruit-bearing trees (like apple, pear, fig and cherry) may require additional pruning after harvest to promote the following year’s crop. Pruning of fruit trees varies by kind, and you should consult your local nursery, garden center or extension agent for detailed information.

While pruning is most effective on young trees, it can be performed on almost any woody plant at any time. The exception is any plant that blooms in the spring, as pruning during this time will remove all or most of its flowers and reduce next year’s production.