Because they are grown as much for their elegant branching structure as for their attractive foliage, pruning maple trees is an important part of their care regimen. Although dead or diseased wood can be removed at any time, as with most trees and plants, some seasons are better than others for serious pruning. Knowing when to trim maple trees will help you keep yours healthy and looking beautiful.
Winter is a good time for pruning maple trees because the leaves aren’t in the way and you can clearly see the overall structure of the tree. This is also the tree’s dormant period, so it won’t bleed excessive sap that will form unattractive blobs at the cuts. To help you decide which branches to remove, try making a basic sketch of the main branches of your tree, then erasing different portions that you’re thinking about cutting away. Use the finished product as a guide while pruning.
Summer is another good time to prune because, with the foliage in place, you can make cuts that will shape the tree or that will thin the leaves, revealing more of the branching structure. Summer pruning does not encourage as much new growth as winter pruning does. Be sure to choose cooler, cloudy summer days for pruning, so that high temperatures and hot sun won’t scorch the newly revealed bark of your maple tree.
Pruning maple trees in the spring while the sap is flowing freely in the branches will result in excessive bleeding. Also, don’t prune while the tree is just putting out its leaves in spring or just dropping them in fall. Maple trees are using much of their energy to perform these functions, and will have less energy to divert to healing cuts. This is especially the case for trees that are struggling, which should only be pruned lightly, if at all.