How to Prune a Juniper Bonsai
The Juniper genus is a broad term for between 50-70 different types of cypress trees. They all require very similar care, pruning, and styles. The most popular Junipers in the bonsai hobby are Green Mound Juniper (Juniperus procumbens nana), Chinese Juniper (Juniperus Chinensis), and the Japanese Shimpaku (Juniperus sargentii).
However, there are many more that are used for bonsai. In this article, we will look at how to prune a Juniper bonsai.
Why Should You Prune a Juniper Bonsai?
There are a few reasons that you would need to prune a Juniper bonsai.
To Keep Your Bonsai Compact
The most important reason for pruning in the art of bonsai is so that you can start to miniaturize your tree and keep it smaller and more compact. By cutting back long shoots, you can develop more compact growth and keep the tree looking like a miniature version of a tree you might find in nature.
To Style Your Juniper
Pruning is also an essential step in styling your bonsai. Without regular pruning, your tree will grow naturally towards the light. This can often lead to excessively long shoots or foliage and branches growing in an unexpected direction.
It can make the tree appear unbalanced. Balance is an essential part of the art of bonsai.
To Train Your Bonsai
Pruning can also be used as a way to train your bonsai, known as the cut and grow method. It’s good to know that, although regular pruning is required to keep your Juniper’s shape well balanced, these species prefer a combination of the cut and grow and wiring training methods to get the best results.
Get More Light Into the Inner Structure of the Juniper
Junipers tend to have very thick and dense growth. The problem with this is that it can lead to no light penetrating the tree’s inner parts and the foliage there dying. This effect can be unsightly and can affect the overall look and health of your tree.
By pruning strategically, you can thin out the growth of the foliage and the light to penetrate the inside of your tree to keep all parts of your bonsai healthy.
When Should You Prune a Juniper Bonsai?
Knowing when to prune a Juniper bonsai is a significant part of owning this species. It’s essential to be aware of when the best times are to do the various forms of pruning. Although there are recommended seasons for the different types of pruning, it’s vital to know that the tree’s health always comes first.
Sometimes it may be necessary to do some pruning when it might not be the ‘right’ season to ensure that your tree stays healthy. Knowing when and how to do this comes with experience, so don’t be scared to reach out to a bonsai community if you are unsure.
Structural or Heavy Pruning
Structural or heavy pruning is what will give the tree its shape. When we structurally prune our trees, we remove unwanted branches and change the style and look of the tree. It’s an essential part of bonsai as it will eventually turn your tree into a bonsai.
Structural pruning is best done in late winter or early spring, just before the growing season. You might also get away with structural pruning in late autumn, just after the growing season; however, it’s riskier then.
Maintenance Pruning
Maintenance pruning aims to keep your tree in its desired style or refine that style. It’s also an essential pruning method to encourage growth closer to the inner parts of the tree to keep your bonsai looking compact.
Maintenance pruning is best done during the growing season (Spring, Summer and early Autumn). However, with Junipers, you can do minor maintenance pruning throughout the year.
Root Pruning
Root pruning is a fundamental yet often overlooked form of pruning that has to be mentioned. Root pruning should only be done during repotting. You should repot your Juniper bonsai every two years, although older trees can go for longer before having to repot.
Pruning the roots ensures that your tree remains healthy but also that your tree stays small. Another reason that root pruning is so vital is that it helps develop a nice, balanced nebari (surface roots) in your bonsai.
How to Prune a Juniper Bonsai?
Now that we’ve covered the types of pruning available, we need to look at how to prune a Juniper bonsai.
You will have to start with an idea or style in mind. Never just go in and start cutting for the sake of cutting. Spend some time with your Juniper. Look for interesting features that you want to showcase. Decide what style will work best with the tree’s current growth. Once you have a plan in mind, you can start pruning.
First, you will need to clean up the tree. It will entail pruning any new growth in the crotches of branches or even new growth sprouting from odd and unwanted places such as the trunk. Cleaning up the tree also includes trimming back the new growth. Don’t hedge prune your Juniper as this removes too many growing tips.
Next, you start working from the bottom of the tree up and start removing any unwanted branches. These will be any branches that grow straight up, curve inwards towards the trunk, or branches growing parallel to one another.
Also, remove branches where three or more extend from the same node. You want only two branches from one node to have a nice balanced ramification.
Now you will start refining your tree. This needs to be done carefully not to remove too much foliage. Only cut back a few of the leaves, keeping as much new growth as possible. With Junipers, it is important to cut back any foliage straight to the branch as the new foliage will only grow from there.
Tools Needed to Prune Your Juniper bonsai:
- For thick stems and trunks, you will need Pruning Shears.
- For shaping and maintenance, you will need Pruning Scissors.
- Disinfect all tools with at least 70% Rubbing Alcohol.
Final Thoughts
A Juniper can be a very rewarding bonsai to grow. They are resilient and beautiful, and their foliage remains a lush green throughout the year. Knowing how to prune a Juniper bonsai is an important step in keeping it healthy and ensuring that you will be able to enjoy it for many years to come.
