The Right Time to Prune Maples
Roger Cook explains when and where to prune
My two young maple trees are growing nicely, but they’re getting too full. When is the best time to prune them, and where should I make my cuts?
—Butch Ostman, Baldwin, WI
In general, the best time to prune maples is in the late spring or summer, after they have fully leafed out. Trimming maple trees earlier earlier in the year allows large amounts of sap to weep out of the cuts—as you would expect from a tree that supplies us with maple syrup. This shouldn’t harm mature specimens, but it may weaken young trees like yours.
With any tree, the best pruning strategy is to first remove dead, damaged, or diseased limbs. Next, go after the ones that are crossed, rubbing against each other, or growing toward the center of the crown. Then snip off the suckers. Make all cuts perpendicular to the direction of growth, and don’t cut into the branch collar, the slightly swollen ring at the base of each limb.
You’ll need a pair of sharp pruning shears for those easy-to-reach twigs less than ½ inch across. Loppers can handle the ones up to about an inch wide. A handsaw will take care of anything bigger. For limbs you can’t reach, use a pole saw with loppers.
When sawing those bigger limbs, always use the three-cut method. About 2 feet from the collar, cut a third of the way into the underside of the limb. Then cut into the top of the branch 2 inches farther out from the first cut, and saw all the way through. The undercut stops the falling limb from ripping off the bark and leaving a gaping, hard-to-heal wound. Now, with most of the limb’s weight gone, make the third cut next to the branch collar.
After this initial cleanup is done, step back and assess the tree’s overall shape. The goal is to open up some space between limbs without making the tree look sparse or unbalanced. So before you remove a healthy branch, take a moment to visualize what the tree will look like when it’s gone. Don’t rush; once a limb is cut off, it can’t be put back.
Don’t get carried away, either. You shouldn’t remove more than 30 percent of the crown at a time. Any more than that will hinder the tree’s recovery. Remember, you can always do more pruning next year.
Shown: Roger Cook prunes a maple tree using a pole saw fitted with a rope-controlled lopper. With this tool, Roger can do almost all of his tree-pruning work while standing safely on the ground.