When Should You Prune Your Bonsai?

I get a lot of messages from people asking me when they should prune their bonsai and I always feel a bit stupid telling them that they need to do it when its needs done.

Sometimes I tell them they need to prune when the tree tells them, which is an equally ridiculous answer, but both these things are very true.

You need to be able to look at the tree and know that it is ready to be pruned, as well as look at your own objectives and then make the decision.

 …this sounds much more complicated than it really is and I will go through some things you need to think about, or look at, and then once you put that all together, you will know exactly when you should be pruning your tree and when you should be leaving it alone.  

What Are Your Goals For The Bonsai?

The first thing you need to look at is your goals. What are you trying to achieve with the tree and how will pruning help that?

If you are trying to thicken something up, such as a branch, you need to look and see if that has been achieved. If you want more thickness, then pruning isn’t really going to help you, it just going to slow things down. However, if you are happy with the thickness, then pruning is going to going to be an option.

These goals are of course going to change over time as you move from development into refinement, but either way you need to ask if pruning will help you achieve what you are aiming for.

Prune Your Bonsai When It Is Healthy and Growing

You want to be pruning a healthy tree that is growing, if your tree is sick or not performing well then it is probably weak and pruning is only going to make it weaker.

If you have ever seen any of my videos you will often see that I let the tree shoot out and become a crazy mess. This may look strange, but it’s done for a reason. When the shoots get that long I know the tree is healthy. I know the tree is producing a lot of energy and I know if prune it back at this point it will just bounce right back like nothing has happened.

Of course this needs to be linked back to the goals, if I am trying to refine a tree, then pruning it at this point makes sense. When it re-grows it will push out two new smaller shoots from wherever I pruned, making it more refined …and achieving the goal.  

(You can read more about – How Can You Tell If Your Bonsai Tree Needs Pruned?)

Prune Your Bonsai When You Want To Make Structural Corrections To The Tree

When you are growing a bonsai you will want the tree to grow to a certain shape, which means you will have to prune things off to achieve this.

The tree may want to grow in a certain area, and if this isn’t want you want, then you will need to prune it back and try to direct the growth into the direction you want.

You will have to analyse the structure of the tree and prune off anything that doesn’t quite fit with what you want. Some of these cuts may be large and drastic, while others may be small, either way they all add up to make the structure that remains look better.

A good time to do structural correction work is in late winter, just before the tree wakes up for spring.  

The leaves will be off, so you can actually see the structure and make better decisions, but you will also be setting the tree up nicely for spring. When it wakes up, all the energy is going to go into areas you want to actually grow, since you will have removed all the parts you don’t want.

(You can read more about – How Do You Know What Branches To Prune On A Bonsai?)

Prune Your Bonsai When You See Problems About To Occur

You can also prune your tree if you start to see problems occurring. This could be linked to structural pruning as it is very similar, but usually this type of pruning is done on an area of the tree you initially thought was decent.

Normally this will be things like inverse taper, or just too much general thickness in an area. You might see this starting to develop and realise it doesn’t look good anymore and it is only going to get worse if you do not address it.

I normally do work like this in late winter, which is why all the work can all look the same, but really you could do this work at any time.

Luckily trees grow quite slowly, so if you do see a problem developing you can take a while to think about what to do, before having to actually do it.  

What Time Of Year Should You Prune Your Bonsai?

While you can technically prune a bonsai at any time, it really depends why you are pruning. If you are making hard cuts and removing a section, this can really be done at any time, but you may want to be more cautious and wait until certain times of the year.

Basically every time you prune you will be weakening the tree and it is also going to try and respond to the work you do, which really means you want to prune at a time when it can actually respond and have enough of the growing season left to actually recover fully.

Ideally you want to prune in late winter, or in the summer. Spring may look like a good time, but you want to leave the tree alone too just grow and then in autumn things will be slowing down and getting ready to shut down for winter, where the tree is dormant. (This is why we wait to very late winter to prune)

(You can read more about – How Often Should You Prune A Bonsai?)

Conclusion

Hopefully this gives you more clarity around when you should prune your bonsai.

If your goal is to prune the tree, then you need to check that it is looking healthy and can handle what you are planning on doing.

Then all you need to do is make sure it is the right time of year, so the tree has enough time to recover and if all this lines up, then you can prune the tree.

(You can read more about – How To Prune A Bonsai Tree – A Beginners Guide)