The Japanese red maple's stately beauty adorns many gardens and yards in the United States. The tree grows best in U.S. Department of Agriculture hardiness zones 5 through 8, although it can grow in zone 9 as well. The Japanese red maple should never be pruned in the spring when the sap is rising, and no more than one-third of the tree should be removed at one cutting. If more than one-third of the tree should be trimmed, spread the cutting over two years.
Use sharp pruning shears or pruning saw to remove any dead or diseased branches.
Branches more than 1-1/2 inches in diameter should be cut using the three-cut method. Start by cutting about halfway through the branch from the underside three inches past where you would like the final cut to be.
Make a second cut all the way through the branch from the top side three inches beyond the underside cut. As the top-side cut nears completion, the branch will break off at the point of the underside cut, preventing the branch from tearing large strips of bark from the tree as it falls.
Cut the 6-inch stump off, leaving the branch node (swelling) where the branch was attached to the trunk.
Remove branches that are crossing and rubbing against each other. (These branches can rub off bark and allow disease to enter the tree.) Cut off one of the branches just above the node (swelling) where the branch attaches to the trunk.
Cut branches that are growing sideways across the interior of the tree's canopy.
Step back and look at your tree, deciding which branches should be removed to create a more pleasing shape. Remember not to remove more than 1/3 of the green branches from a Japanese red maple during any one pruning.
Remove narrow-angled branches (also known as narrow crotches), as the bark in the crotch can become diseased. Remove the entire branch containing the narrow crotch just above the node on the trunk.