Most Japanese maples are easy to grow once they become established and are trained to grow properly. One of the best ways to keep a Japanese maple healthy is through pruning. Some Japanese maples can be pricey, and people often have a plant-it-and-forget-it attitude with trees, but this is an essential care task you shouldn't skip.
Here's our best guidance on when and how to prune Japanese maples with instructions so easy even a beginner can do it.
Why Prune Japanese Maples
Japanese maples should be pruned for health and aesthetics (i.e., its shape).
Remove any dead, dying or broken branches, then prune for aesthetics with what's left. Prune it to establish its shape or to maintain a shape. Make no mistakes; every form of Japanese maple, whether weeping or upright, must be pruned to keep its visual appeal.
If you feel tempted to skip pruning a Japanese maple for health, remember that you can't have a good looking tree if it isn't healthy.
When to Prune Japanese Maples
Like most trees, Japanese maples should be pruned when the tree is completely dormant. Usually this occurs anytime between the first frost and late winter. However, Japanese maples take extremely well to pruning and can be pruned throughout the year, if needed.
Plan to prune the Japanese maple as a part of an annual health inspection you do when it's dormant in the winter. Make sure to assess it again after it leafs out (i.e., the buds open). At that point, examine its form and see if there are any dissimilar leaves. Look at the overall shape of the tree to see if you like it. Unless you pruned too much, your tree should have not suffered any negative effects.
Tips for Pruning a Japanese Maple
It is hard to believe, but pruning a Japanese maple is easy. You know what we want it to look like and what does not belong on a tree (broken, dying, or dead branches), and that is the most important thing.
You always want to start by cleaning your tools with a solution of 90% alcohol or higher or a solution of bleach and water. Cleaning your tools sanitizes them and reduces the risk of spreading pathogens between tools and plants.
Follow these guidelines for pruning a Japanese maple:
- Always prune away any lower branches that look different or have dissimilar leaves from the top of the tree.
- Remove the BDD (broken, dying, or dead) branches.
- Stake young trees to ensure they grow upright.
- Always use the proper tool to prune a Japanese maple: use hand pruners for branches up to 1/4 of an inch in diameter, loppers are used for anything up to 2 inches, and a pruning saw for anything larger than 2 inches.
- Never prune more than 1/3 of living tree material per year.
- Pruning cuts should always be made as close as possible to the collar without cutting into the collar itself.
Pruning Upright vs. Weeping Japanese Maples
Pruning these two types of Japanese maples is entirely different. You will do your normal yearly maintenance on both, but pruning to achieve a certain look will be very different.
With weeping Japanese maples, imagine a line across the trunk and cut above it to obtain an umbrella-like form. Remove all dissimilar-looking leaves on lower branches. Repeat this process yearly until the tree reaches maturity, and then prune as needed to maintain the umbrella shape. If you're starting with a young tree, stake it to achieve an upright habit. (Once it's established, remove the stake.)
If you have a Japanese maple with an upright form, look for dissimilar leaves and branches along the trunk and remove them. These are branches growing from the grafting stock. After removing these branches, you should decide whether you want your tree to have a single leader or be multi-stemmed. Most Japanese maples look more appealing as a multi-stemmed tree, but it's fine to grow it with a single leader. Establish one, three, or more leaders by removing any extra branches. Do not leave two leaders, as this can cause splitting. Continue to prune yearly, allowing the leaders to develop height and lateral branches.
Should I cut the lower branches of a Japanese maple?
Whether or not you should cut the lower branches of a Japanese maple depends on whether the tree is grafted onto rootstock, a weeping variety, or how many leaders you'd like your maple to have. The only time you should definitely cut the lower branches is when there are dissimilar leaves growing on lower branches that look different than the branches higher on the trunk.
How do you prune and shape a Japanese maple tree?
How you prune and shape a Japanese maple depends on its growth habit — whether it is weeping or upright. Weeping trees require not just pruning but also training. Trees grafted onto rootstock should receive pruning for health and aesthetics, but also to remove suckers.
Can you prune Japanese maple in fall?
You can prune Japanese maple in the late fall, early winter, or late winter. The best time to prune is when the tree is completely dormant. With this being said, if the tree needs to be pruned at any point, go for it. Japanese maples generally take to pruning very well.