Maple tree pruning may be done in the spring, with the best months to prune being the time immediately after leaves appear. If you prune the tree in the winter or springtime, the sap bleeds or runs out. While this won't harm the tree, it doesn't look very pretty, so prune the tree in late spring if you can.
Maple Tree Pruning Tips
Most experts agree that you shouldn't prune more than 15 percent of the maple tree in any one year. It's better to prune a little bit each year than to prune a lot one year.
What to Prune
You can prune off little twigs coming off the stem of the maple tree. By pruning off the little branches, the tree will put further energy into growing up and out into the larger branches.
How to Prune
Always use sharpened pruning shears or loppers specifically designed to cut through tree branches. Prune as near to the trunk as you can. Make cuts at an angle, and make the cut as close to the living part of the tree as you can. Specific directions on how to prune can be found on North Carolina State University's website.
Caring for Equipment
After pruning trees, dip the pruning shears and other equipment into a bucket filled with one tablespoon of bleach to a gallon of water. Rinse off, dry and store carefully. The bleach and water solution kills any bacteria or fungi that may be on the equipment. These can infect the next plant you trim if they're not cleaned properly.
Pruning Problems and Questions
Several very common problems and questions arise when discussing maple tree pruning.
If you pruned your maple trees and the next day there's liquid running from the pruning spots, don't panic. The liquid is simply sap. While it's more likely to run during the fall and early winter, it can run at any time of year. The pruned areas won't heal as quickly if the sap is flowing freely, which is why many arborists recommend waiting until the late spring or summer when the sap is least likely to run before pruning.
You may also see your maple trees oozing sap during other times of the year. Check the trunk for teeth marks, particularly in the fall or winter. Squirrels and other creatures love the sweet taste of maple sap and may even bite the trunk to start the sap flowing if they know what sweet taste is in store for them. It won't harm the tree, but it can be scary if you don't know what the stuff is running out of your tree.
Trees Near Power Lines
It's best to avoid planting trees directly under power lines, but if your tree was planted before you moved into your home, or it's grown more aggressively and vigorously than planned, you need to decide whether or not it should be pruned. If the utility lines are publicly owned, the utility company will prune the tree. They will probably prune it very drastically. They have to; branches that entangle power lines can pull down the lines in a storm, disrupting service for many. Don't try to trim trees near power lines yourself. Call the utility company or a tree service.
Unfortunately, if you got carried away and over pruned your tree, there's nothing you can do right now. It's like getting a bad haircut; you have to wait for it to grow back. Hopefully you didn't prune away too many branches and weakened the tree. Remind yourself the next time you reach for your pruning shears not to go overboard!
Painting the Pruned Spots
In years past, horticulturist recommended painting over or sealing the trunk of the tree where the branches were pruned off. Newer research indicates that this isn't necessary; the tree heals itself effectively, sealing over the pruned areas and creating its own scar. So there's no need to bandage the pruned areas or paint them. Just leave the pruned areas alone and let nature seal it off.