Tree Care

How to Prune a Tree


All pruning should be done with a goal inmind. Generally, trees respond best to pruning when they are young. Pruning stresses older trees. The Atlanta tree ordinance prohibits removing more than 20% of a tree's foliage (or live limbs during the dormant season). When pruning a young tree to improve its structure or a mature tree to provide clearance, take into account the size, age, health and species of the tree, as well as the season. The American National Standards Institute maintains guidelines for pruning trees (ANSI A300), which tree professionals should follow.

All pruning cuts should be made at a natural node, or lateral branch, and should not leave a protruding stub. For example, to provide clearance for a house by removing a three-inch diameter limb, cut the limb to a lateral branch or the branch collar if possible.

To avoid causing damage to a tree, pruning cuts should be made just outside the natural branch collar, which is the area of raised bark near the limb's attachment point. For larger limbs, the three-cut pruning method will reduce the risk of damage from peeling or splitting. To perform this process, first cut the limb far enough away from the trunk to avoid damaging it with the saw. Saw part way through the limb from the underside, then cut the limb off from the top to meet the first cut. The third cut removes the branch stub at the branch collar. Generally, a good pruning cut results in a perfect circle.

Structural pruning for young trees should focus on removing or subordinating co-dominant limbs (double trunks) and large lateral limbs. The purpose of structural pruning is to promote healthy growth, and to reduce the risk of future branch failures.

Refer to the website of the Georgia Arborist Association to find a local arborist certified by the International Society of Arboriculture (ISA).