Japanese maple trees are naturally eye-catching trees with bright red leaves and winding branches. Japanese maple trees can be left to grow on their own. But training the young trees and annual pruning are both excellent ways to enhance your Japanese maple tree’s natural beauty and shape.
Pruning your Japanese maple tree is beneficial for your tree not only because it can enhance your tree’s attractive shape (if done correctly). But it also helps keep it healthy by opening up circulation and allowing your tree to breathe. At the very least, it is necessary to prune away dead leaves and branches on your Japanese maple trees. Be sure to prune your tree in the winter or on cooler summer days. You can stick to light cosmetic shaping or more detailed layering which will create the graceful, layered shape for which Japanese maples are most often recognized.
When pruning your Japanese maples, there are several things to keep in mind. Be aware of the time of the year, what you should clip, and how much you should remove from your tree before you begin pruning.
About Japanese Maple Trees
Japanese maple trees (Acer palmatum) are well-liked trees that showcase a variety of bright colors throughout the year. They can be kept as full-grown trees, shrubs, or even trained to be container plants, provided that you have the correct variety. This article will focus primarily on how to prune the larger, tree-like varieties of the Acer family, rather than the smaller shrubs.
If you would like to learn more about Japanese maple trees in general, check out our article on Japanese maple planting and care.
Pruning Different Types of Japanese Maple
Before you begin pruning your tree, it is helpful to know exactly what type of Japanese maple tree you have. This knowledge will help you determine what your tree should look like based on what its natural growing tendencies are.
It will also help you to avoid forcing the tree into something that is not its natural shape. When pruning a tree, always work with the tree’s natural growth pattern for optimal results. There are two main types of Japanese maple trees – the upright variety and the weeping variety. The upright variety will grow 15+ feet in height. The weeping variety is smaller in size. It will likely only grow to be around 6 feet tall, but it will be wider, naturally, than its upright growing counterpart. And it will have the characteristic cascade of leaves that make it look like an umbrella.
The general rules of pruning these two varieties will be similar, but they will look different as they grow. Be sure to keep that in mind when training and pruning.
When to Prune Japanese Maples
The helpful thing about Japanese maple trees is that they do not require pruning. It only enhances their natural features. For most minor shaping and cosmetic pruning, you can prune your Japanese maple tree any time of the year. To be extra nice to your tree, avoid any major pruning during early spring when new growth is occurring. Pruning during the growing months can be more traumatic for your tree.
But for more intense trimming, it is recommended that you wait and prune your tree in the winter or summer. Plan to prune your tree once in winter and again in the later spring/early summer if you are shaping it. In winter, all the leaves have fallen from your tree. Do your more specific shaping of the tree during this time. With no leaves on the tree, you will be better able to see the overall branch architecture. This visibility can help you better determine how best to shape it to your liking.
Pruning in the summer is best for thinning out your tree’s branches to keep it well-circulated and airy. You can also encourage leaf layer growth during the summer months to help your tree develop its layered umbrella appearance. Although, if you are pruning in the summer, be sure not to prune in the middle of the day when the sun is hottest. As a general rule, it is best not to prune your tree if the temperature is 80 degrees Fahrenheit or warmer.
If you prune your tree when it is this hot out, you risk scorching the recently exposed parts of the tree that may be used to shade from other branches. Plan an annual pruning of your tree during the summer and winter to keep it under control and properly shaped.
Tools for Pruning Japanese Maples
Japanese maple trees are relatively slow-growing trees. Their branches, for this reason, are usually small.Medium pruning shears will likely be sufficient for most of your pruning needs. Though, it may be helpful to have a handsaw and a ladder handy if you are pruning an older tree. These will help you remove the larger branches.
Be sure your pruning clippers are sharp to help ensure clean, smooth cuts. Clean cuts will help your tree heal faster, and sharp clippers will help you prune easier. It is also important that your pruning shears have been cleaned. This helps avoid the possible transfer of disease and pests from any plant that has been pruned recently. Below is a list of recommended tools you should have on hand before you begin pruning your Japanese maple:
- Medium pruning clippers
- Handsaw for larger branches
- Safety glasses
- Ladder (depending on the size of your tree)
- Pole pruner (depending on the size of your tree)
Always be mindful of where you or any other nearby individuals are before you prune any large branches. And be sure to wear safety glasses and gloves to keep yourself and your eyes protected.
How to Prune a Japanese Maple
Before you begin making any cuts, study your tree to understand its existing structure. At the very least, you will need to remove all dead branches and leaves from your tree. Start there. Your general objective beyond basic clean-up of your tree will be to keep the branches layered. You ideally want to get the branches of the tree to overlap each other in a canopy. You want to be able to see through the branch layers. Working from the bottom of the tree upward, make sure there are not branches rubbing together or growing parallel to each other.
What to Prune off Your Japanese Maple
Criss-crossing branches can be prime breeding grounds for pests and dieseases. Removing these will avoid unwanted disease to your tree, with the added benefit of cleaning up its shape. Branches growing in the wrong direction (inward) or straight up can also be removed. Clearing away smaller twig growth near the trunk of the tree or on extending branches also keeps the branches and layers clean.
When clipping, be sure to make a diagonal cut. This keeps rainwater from accumulating in the new cut and helps the tree heal faster. Remember that you are pruning for width and shape. Never try to prune for height, as this can rarely be done without damaging your tree. Instead, it is better to make sure you plant the proper type of tree for your yard and space. This will ensure that you do not have to worry about the tree’s height down the road.
There is a general rule of thumb that you should never prune more than one-fifth of the Japanese maple’s crown. And you should not take more than 30% of the tree at any given time. Doing so will only stimulate unwanted shoot growth and cause stress to your tree. If you are pruning an older tree that has not been pruned and need to remove several lower branches, do not remove them all at once.
Remove a couple at a time to avoid stressing your tree. In short, best practice is to take off less than you want to. You can always come back and prune more!Step back frequently, as well, to make sure you are pruning effectively and keeping the whole tree in mind. Japanese maples do not handle over-pruning very well. Most young trees will need very little pruning. But you can help shape and enhance your tree by training it young. If you want to train your tree, begin to do so when it is about 2-3 years old. Young trees will primarily only need their lower branches pruned for clearance. Wait until the tree is more mature before you subject it to any major shaping.
Redirecting Japanese Maple Tree Branches
One tactic often used in pruning is redirecting growth. This tactic is very useful in bringing out your tree’s natural shape. To do this, you essentially are taking smaller branches away to redirect the nutrients they are receiving to other branches. Almost always, branches should make a “Y” shape. If there is a smaller branch in the middle, remove it, and redirect that energy towards nearby branches. Always redirect or cut above a branch that is no less than one-half the diameter of the branch you are cutting. This is referred to as the “half-diameter rule.”
Three-Cut Method Pruning
If you need to cut large branches on your Japanese maple tree, use what is called the three-cut method. This method keeps the bark from tearing as the tree limb falls. To practice the three-cut method, first cut into the bottom of the tree branch about halfway through (6-12 inches into the trunk). Cut 1/3 of the way up the branch. Then make another cut, several inches away from the trunk of the tree, from the top. Your third cut can be closer to the trunk to clean up the remaining stub. But be sure to keep the collar, the inch or two of the branch closest to the tree, untouched.
Pruning Damaged Japanese Maple Trees
Sometimes pruning will be necessary because your tree has experienced damage from extreme weather. New growth shoots will likely begin to develop under the dieback of the tree. It is necessary to exercise self-restraint when pruning these new shoots. It may be tempting to remove all the new growth to get your desired look all at once. However, doing so can ultimately harm the tree. Those new shoots can provide some level of protection to recovering branches.
Not only that, too extreme pruning will encourage new growth that may make your tree more difficult to prune down the road. Only prune about ⅓ of the small shoots the first year after your tree received its damage. It may take several years to get your Japanese maple tree to where it was before it was harmed.
Pruning Sick Japanese Maple Trees
Japanese maple trees handle pruning very well. But, if your tree is sick, it may be best to avoid any major shaping or pruning. Instead, remove only dead leaves and branches from your tree.
Pruning Japanese Maple Seedlings
Young Japanese maple trees do not require much pruning, apart from the stray shoot here and there. It may also be needed if they are growing lopsided. But if you purchase a new Japanese maple seedling, it is always a good idea to prune the top of the plant to help it develop its roots. Many gardeners are hesitant to do such pruning. And this fear is for good reason! It may feel like you are ruining your growing little tree, but it is great for the plant’s roots system and future development.
Japanese maple trees do not necessarily require a lot of pruning, but regular pruning can enhance your tree’s natural beauty and shape. Be sure to prune when your tree is not actively growing. Take less than you want to from the tree- you can always come back to it! And take regular breaks to be sure you are keeping the tree’s natural architecture in mind.
Do you have more questions about how to prune your Japanese maple tree? Drop us in a comment below! We look forward to hearing from you! If you found this article helpful, share it on social media!