This is an archived story; this page is not actively maintained. Some or all of the links within or related to this story may no longer work.
For the latest University of Minnesota news, visit Discover.
Figure 1: Bark ridges on a branch.
Pruning cuts every gardener should know
By Patrick Weicherding
From eNews, March 20, 2008
Pruning is the best preventive care you can give a young tree. It helps the tree develop a strong structure and can promote tree health. The ideal time to prune is late winter or early spring because you can minimize the exposure of the tree's pruning wounds to fungal spores and insects that transmit disease.
One of the most important aspects of pruning trees and shrubs is how the job is done. If branches are improperly cut or if care is not taken during the pruning process, the plant may be permanently damaged and plant health impaired.
Here are some basic pruning cuts that every gardener should know:
When pruning trees, make the final cut just beyond the branch collar and the branch bark ridge. The branch collar is the swollen area at the base of the branch. The branch bark ridge is the dark, rough bark ridge that separates the branch from the main branch or trunk (Figure 1). The primary objective is to make the smallest possible wound, which will seal over in the shortest possible time.
Figure 2: With small branches less, place the blade of pruner at the branch collar and cut up.
Small branches less than 1⁄2 inch in diameter can be removed with pruning shears. Place the blade of the bypass pruner at the branch collar and cut up (Figure 2). Leave the branch collar on the tree, since it is important for the wound sealing process. Do not make the pruning cut perfectly flush with the stem, as this will result in a larger wound.
Remove larger branches greater than 1.5 inches in diameter with a pruning saw using the three cut method to prevent trunk bark stripping. Make the first cut about 1 to 1.5 feet from the main branch or trunk. Cut upward and go about one third or halfway through the branch. Make the second cut a couple of inches beyond the first. Cut downward completely through the branch or until the branch breaks free from the remaining branch stub. Make the final cut just beyond the branch collar.
When shortening a branch or twig, cut it back to a lateral (side) branch or make the cut at a slight angle (45?) about 1⁄4 inch above the bud. Do not make the angle of the cut too steep nor too close or too far from the lateral bud.
Remember, proper pruning technique is essential in developing tree and shrubs with a strong structure and desirable form. Trees and shrubs that receive the appropriate pruning measures in the correct way while they are young will require little corrective pruning when they mature.
Call a certified arborist for help pruning large trees.
Pruning tool Most pruning tasks in the home landscape can be accomplished using very basic pruning tools: hand pruners, lopping shears, pruning saws, pole pruners, or hedge shears. It's important for safety reasons to use the right tool for the job. So ask a store clerk for advice if you're unsure of what to buy. And always shop for quality and durability before price.
Patrick Weicherding is a regional extension educator with University of Minnesota Extension.