Pruning Japanese Maple Bonsai is a key aspect of maintaining and shaping these exquisite miniature trees, which are highly regarded in the art of bonsai cultivation. This delicate process requires skill, patience, and knowledge of the tree’s growth patterns and characteristics.
In this article, we will explore the basics of pruning Japanese Maple Bonsai, including the reasons for pruning, when and how to prune, and the important considerations to keep in mind for a successful pruning session. For the overall bonsai care, continue reading Japanese maple bonsai care.
Why prune Japanese maple bonsai
There are several important reasons for pruning Japanese Maple Bonsai
- Shaping: Pruning is essential for shaping and maintaining the shape of Japanese maple bonsai. Furthermore, some varieties of Japanese maple such as “dissectum“, naturally grow quite congested with a lot of crossing branches. This contested growth habit can only be controlled and shaped with the help of pruning. This will also help in preventing the dieback of inner branches in the tree due to congestion and lack of light.
- Increase vigor: If pruned at the right time (i.e. in early spring), the tree will rapidly push new buds, resulting in lot of new growth. To increase the growth rate of your Japanese maple tree, pruning is much more effective than heavily fertilizing it. Continue reading about fertilizing Japanese maple bonsai tree.
- Controlling the growth rate and size of the tree: By performing pruning at various seasons of the year (discussed further in the article) you can also control the vigor and size of your Japanese maple bonsai tree.
- Good health of the tree: Pruning is also essential for maintaining good health of your bonsai tree. Activities like removing dead/diseased/weak branches and foliage, removing congested growth from the inner sections of the tree, trimming the canopy of the tree to enable light and air to pass through, removing unwanted branches etc, will greatly improve the health of the tree.
- Establish the roots: Pruning is not only good for the health of the tree, but also promotes expansion of the root system and establishing the root ball.
- Improved branch structure: By selectively removing certain branches and encouraging others to grow in specific directions, the bonsai artist can achieve a strong and visually appealing branch structure. Well-defined primary and secondary branches contribute to the tree’s overall aesthetics.
When to prune Japanese maple bonsai
The Japanese maple bonsai can be pruned throughout the year. Pruning at different times of the year, however, will result in different effects. For example, early spring pruning will induce vigorous growth, late summer pruning will reduce the size of the tree, fall pruning will induce slight new growth – however it is not recommended, and winter pruning is done for removal of large branches.
Pruning Japanese maple bonsai in spring
To stimulate vigorous growth of the tree, It is best to prune your Japanese maple in early spring. The tree is at the peak of its active growth stage. This is also one of the most appropriate time when the tree is fertilized. Hence, both these factors combine and the tree responds well to pruning with a lot of new growth. (Fertilizers help the tree in responding more quickly to pruning).
This is specially helpful in the case of young trees as when the tree is young, you want it to grow as much as possible. If you want more vigorous growth, more branching from pruning, and a healthier plant, early spring is the best time. This is right when the buds are leafing out. It will also increase the energy of the plant, increase the root ball, and increase the secondary flush of growth.
If you prune the tree at this time, you will also need to do relatively more maintenance pruning.
Some bonsai growers are afraid to prune the tree at this time as the tree bleeds profusely in this season. However, do not be scared to see this bleeding. The tree is actively growing and will heal quickly, usually in a week. On the other hand, pruning wounds might take as long as 3 weeks to heal in other seasons.
Another reason why this is a good time to prune because the tree has not leafed out yet. Because of this you can easily see the branch structure of the tree. This will help you in clearly visualizing the shape of your bonsai.
Pruning Japanese maple bonsai in summer
For controlling the size of the tree or to reduce the size of the tree, some bonsai growers perform pruning in late summer. At this time the shoots have hardened. Summer pruning will slow down the growth of the tree. Hence, mid to late summer pruning is a good time to decrease the vigor of the tree.
One thing you need to keep in mind is that if you are not planning to do a lot of maintenance pruning, do not prune the tree in spring. Instead do it in summer. For a detailed guide on structural and maintenance pruning, please read pruning a bonsai tree.
Pruning Japanese maple bonsai in fall
Even though you can prune your Japanese maple bonsai in fall, it is generally not recommended in colder regions. On the other hand, in warmer regions the risk of fall pruning are reduced.
Fall pruning will induce slight new growth on the tree. We don’t want the tree to enter the winter season (dormancy) with this slightly active state. The tree will be more prone to infections, diseases and damage.
Pruning Japanese maple bonsai in winter
Winter is also a good time to prune Japanese maple bonsai. Whenever you prune in winter, prune the branch to a shorter length then you generally do. This is because, if not done this way, in spring the tree grows vigorously and the branch will be longer than you intended it to be.
The tree also bleeds less at this time of the year.
In winter, the energy of the tree is stored in the roots and the lower part of the trunk (away from the branches). This energy is again pushed to the branches when the growing season starts. Remove all the unwanted branches at this time. In this way you will not waste tree’s energy on unwanted branches when the spring season arrives and the tree starts to grow again.
How to prune Japanese maple bonsai
First and foremost, don’t be afraid to prune your Japanese maples. The right knowledge will give you confidence and the best success rate. Prune at the right time and follow the correct method and you will be fine. Also, don’t be afraid to make mistakes. The tree will grow back again.
You will need bypass pruning shears, concave branch cutters, a saw, rubbing alcohol, and a cloth when pruning Japanese maple bonsai trees.
It is extremely critical to clean pruning tools with rubbing alcohol before and during pruning. Pruning also includes the removal of dead or diseased parts of the tree. By constantly cleaning the tools you will prevent the spread of disease to other parts of the tree and to other plants.
Do not use concave cutter for large branches. You can use large concave cutter or saw for thick branches. Please read guide to bonsai tools for more details.
Now a lot of new bonsai growers will ask- “how much should I prune“. It is possible to prune almost 40-45% of the tree in one pruning session. Do not prune beyond this. Pruning should be divided over several seasons if you wish to prune more.
Following are some of the factors to keep in mind while pruning Japanese maple bonsai tree:
- Let the young tree grow. These trees naturally develop a central leader. Even if you accidentally remove the central leader, the young plant will regrow a dominant central leader.
- If you have a young plant, do not prune it too much. Let it grow for a few years (at least 2-3 years). This will also help the plant thicken its trunk. Please read how to train your Japanese maple sapling into a bonsai tree. Young plants are mostly pruned to establish a leader (when you are not happy with the main leader and want to develop a secondary leader).
- While pruning, remember the rules of bonsai. Keep in mind, however, that bonsai is an art. Different people will prune the same tree in different ways. Prune the tree to a shape you like. Prune it so that it has a three-dimensional shape.
- Before pruning, it is very important to know the natural shape of your Japanese maple variety. Prune the tree to mimic the natural shape of the tree. Don’t try to shape one variety to look like another variety. Such attempts are usually unsuccessful.
- Remove the diseased and damaged parts of the tree. Especially in colder regions such as zone 5 and zone 6, the tree will have some twig dieback when winter is over. Remove these twigs.
- Remove dried branches from the tree. You will see slight discoloration on these dried shoots. Also, these shoots will have a crispy bark. Deadwood takes away energy from the plant. You can do this at anytime of the year.
- Remove twiggy growth (also known as Witches’ Broom). These clusters of thin shoots generally don’t develop into any attractive branches and take away a lot of energy away from the main trunk and branches. By removing this twiggy growth, you will also increase the growth rate of the plant.
- When you prune a branch, it will usually die back to the next available bud. Hence prune it right above the bud. Continue reading How to prune a bonsai tree.
- Prune conflicting branches i.e. branches that are crossing, growing straight up or down, touching branches, branches growing from same spot, branches growing towards the trunk or bending towards the trunk.
- While removing one of the branches that are emerging from the same spot (or even touching or crossing branches), keep the branch that is likely to receive sunlight through the canopy. Preferably, remove the lower branch. This way you can hide the pruning wound.
- When removing branches, do not prune too close to the trunk. Leave a stub (about a centimeter or slightly less). The tree will start to heal underneath the stub. This stub will die back and over time it will become flush with the trunk. Keep the stub at least for a year to see if there is a need to shorten the stub any further.
