Learn about different pruning techniques and how we determine when they should be used.
Pruning is the most common tree maintenance, desired or needed for safety, to improve tree structure, for tree health, and to make the tree aesthetically pleasing. There are many different pruning techniques that arborists use to increase a tree’s health and strength, but all cuts must be made with an understanding of how the tree will respond.
Arborists need to consider that removing live branches from a tree removes a nutrient source and could affect growth. No branch should be removed without considering its potential effects.
Crown Reduction
Crown reduction is a pruning procedure used to reduce the size of a tree and/or the height. This is one of the most difficult pruning methods because the goal is to reduce the size (height or weight) while also giving the tree a nice shape.
Some tips for crown reduction:
- Before climbing or making a cut, visualize the result that you want
- Start with the tallest or widest side
- Try to hide cuts within the canopy
- When reducing multiple trees, start with the tallest tree and try to match the smaller ones
Side Trimming
Side trimming is a pruning procedure used to reduce the size of a tree and/or spread. This practice can help remove a good amount of lateral branches that have the potential to break. When cutting a branch back to a lateral, an arborist should not remove more than one-fourth of its length. The remaining lateral branch should be at least one-third the diameter of the removed portion.
Some trees can handle heavy pruning due to their natural defenses that protect them from diseases and decaying. Other trees, like Beech and Black Locust, lack these defenses and cannot handle as much pruning.
Hand Pruning and Shearing
Using hand pruners helps to give the tree or shrub a more natural look. Electric or gas shears leaves a sharper, but less natural look. If shears are not sharp enough they will leave very rough cuts and remaining leaves will eventually have brown edges.
Heading Cuts
Heading cuts involves cutting limbs to a stub, bud, or a lateral branch not large enough to assume the terminal role. These cuts are often used on small plants and shrubs to stimulate branching. Heading cuts can be made with hand pruners, pole pruners, and shears. However, in larger trees, heading cuts are used inappropriately to reduce size; this is called topping.
Topping is a bad pruning practice that can cause branch dieback, decay, and unstable sprout production from the cuts’ ends. It is so bad that it can be a death sentence for the tree. Topped trees are prone to storm damage due to the weak branch attachment point between the branch and the new sprouts. These water sprouts will grow at a faster than the normal rate, reaching the previous height of the tree within a few years.
