A structurally sound tree should have one single trunk, instead of two or more codominant stems branching from the trunk. Remove or reduce the stem to maintain the dominant leader in the tree.
-Cut branches that are crossing, rubbing, hanging, dead or excited (ones that don’t fit the norm size or direction). On larger limbs, the first cut should be made 12 in. to 18 in. from the limb’s point of attachment. To avoid ripping the stem into the trunk tissue when making a cut, use the three-point method (see Steps 1 and 2). Do not cut into the branch collar. Trees don’t heal if you make an improper pruning cut—they just seal over the area, leaving permanent wounds.
-When pruning the lower limbs, make sure to leave as many temporary branches on the trunk as possible—the tree needs those branches to feed itself. You should clear no more than one-third of the trunk (see Step 3).
-Make sure your pruning equipment—chainsaw, lopper or hand pruner—is sharp. If using a chainsaw on the ground, you should wear a hard hat, safety glasses, gloves, protective footwear, hearing protection and chaps. Chaps and hearing protection are not required when using loppers or hand pruners.
Make an undercut half of the way through the branch to relieve weight from the branch collar. The second cut should be outside of the first cut (farther from the trunk). Cut all the way through the limb from the top down.
Make the final cut next to the tree’s trunk outside of the branch collar. Cut down from the top, and cut all of the way through the branch, avoiding the branch collar.
Use this method to cut rubbing, crossing or hanging branches. Only clear up to 1/3 of the trunk.
Sources: Chris Francis Tree Care of the Alabama Urban Forestry Association; International Society of Arboriculture