Correctly removing a branch from a tree protects the tree from fungal infection more effectively than sealing the wound with pruning paint. Done properly, the tree seals the wound itself and quickly heals over with a layer of new bark. Ragged cuts or cuts in the wrong part of the limb leave dead wood on the tree--an easy entry point for fungi and insects.
Cutting Tree Limbs
Find the branch collar, the whorled ridge of bark that surrounds the base of the branch. Branch collars occur at every fork of the limb and also at the junction with the main trunk. Make a clean cut about 1/2 inch away from the branch collar, leaving a flat surface without splintering.
Use limb loppers to cleanly shear off small limbs up to 1 1/2 inches in diameter. For the cleanest work make a first cut six inches or more from the branch collar. Place the flat jaw of the loppers under the branch and shear the limb with the cutting jaw from the top side downward. With the main weight removed, make a second clean cut 1/2 inch from the branch collar.
Remove limbs too large for lopper work by using a pruning saw. When branches are within easy reach work from the ground. Make a first cut 6 or more inches away from the branch collar. Begin by undercutting the limb by one-third of the limb diameter. Pull the saw from the cut and saw through from the top side. Saw off the stub of the limb 1/2 inch away from the branch collar. Cut partway through from below and finish from above. Removing the weight of the branch first prevents splintering and tearing of the wound.
Prune higher limbs by placing a ladder securely against the trunk of the tree and undercutting the branch with a pruning saw. Do not place the ladder under the branch. Climb down from the ladder and finish the cut from the top down with a pole saw. Remove the branch stub with a final cut 1/2 inch from the branch collar. Work from the ladder with the hand pruning saw for the most accurate results.
In summer, seal large wounds with pruning sealer paint. Apply a thick coating directly to the fresh surface of the cut. Pruning sealer prevents infection when cuts must be made during the growing season. Pruning during winter dormancy allows the tree time to seal the wound internally before fungal spores return on the warm spring winds.