What Is The Best Way To Prune A Bonsai Tree That Has Grown Too Tall?

As much as we try and keep our bonsais small and under control …sometimes life can get in the way and the next thing we know are trees are growing like crazy and they end up being far too tall.

If this happens it is totally fine, sometimes you need to let your tree to grow tall so that it can become healthy and then we can fix the problem by just pruning the tree back down to the size it was, and if we can’t, there are a few things we can do to get around it.

Prune Your Bonsai Back Hard

If you have a tree that is too tall, the easiest thing you can do is just prune it back hard.
This is really only going to work for species that can handle this type of work, such as deciduous trees that will back bud easily, no matter how far you cut them back.

I would wait until late winter so that the tree is dormant, but more importantly it will be without leaves and you can see what you are doing.

You can study the structure and clearly see what has actually made the tree too tall. It could just be one shoot that has gone off like a rocket, or it could be that everything is too tall. Then all you have to do is shorten anything that is too long.

You can use the basic pruning principles to make sure you are pruning correctly. I would imagine that in most cases you just need to shorten the taller branches down to 2 or 3 nodes, or down to some side branches and that will really reduce the length and height, but of course every tree will be slightly different.

You also have the option of getting really drastic with some species and basically doing a trunk chop. If your tree is really far too tall now, and it’s totally lost its shape, you may have to just smash it right back to basically a stump and then rebuild from there.

As I already said, what you do will really depend on the state of the tree as well as what you want to achieve, but pruning the height back either a little, or a lot is always a good solid option if your tree is too tall.

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

Reduce The Trunk Line

In a lot of cases where tree has grown too tall it is usually because the main trunk line has gotten too long.

If you take a step back and look at the trunk, following it up from the base all the way to the tip you will see the primary branches coming off it, going to either side. As you get near the top you should be also able to see this happen too, until you reach the very tip.

An easy way to reduce the trunk height is to just cut back to one of these lower side branches, and make this the new tip.

How far you cut back will of course depend on the individual tree, but making one of the side branches the new leader like this is a very common way to lower the height of the tree.

You Might Have Lost A Lot Of The Shape By Letting It Grow Out

If your tree has grown too wild, as well as too tall, it may have totally lost its shape and you might need to just start all over again with its design.

Sometimes you might be able to prune things back to roughly how they were before, but other times it might make sense to just look at the tree like it has never been worked before and consider it as a piece of raw material.

You can just treat the tree like it was a new piece of nursery stock or yamadori and try and identify the basic structure and go from there.

This is pretty rare as usually even if things are really out of control, the fundamental structure you created before should still be in there somewhere, but it can happen. Different areas can thicken up or die back, so the structure it had before can get lost, and if this is the case then treating it like a new tree is the best way to go.

You Can Try And Work With The Current Height

Growing too tall isn’t always a bad thing. You might be able to keep the tree the height it is and just have a bigger tree.

This will really depend how it has grown and what your plans are, but sometimes working with the new size can be a good idea. If you can keep things in proportion then the tree can still make a great bonsai, even if it is taller than you initially wanted.

Sometimes this might just be the best option as certain aspects may have grown too much and no longer work as a smaller tree, such as the trunk may just be too thick to work as a tiny mame for example, so keeping the tree larger would now just make sense.

What Should You Do If It Is A Species That Can’t Be Pruned Back Hard?

Saying “just prune the tree back” is not always an option as some species cannot handle this type of work.

Conifers do not like to be pruned back aggressively and they certainly don’t like to back bud on old wood, which really means if your tree ends up being too tall, it can be very difficult to get it back down to size.

You can use the trick of reducing the trunk line to a lower branch, and making that the new apex, but if your side branches are particularly long this can be hard to reduce and you are more likely to be forced to work with what you have and try and just create a larger tree over all.

Wire Can Help Reduce The Height Of The Tree

If you can’t cut the tree back, you can wire it down to size instead. If you watch any video where a big yamadori pine or juniper is being styled it can be a real eye opener.

It is very common for these types of trees to be heavily wired and you will see some crazy bends being put into the main trunk line. The tree can almost be folded in half at times and while this sounds silly, the results speak for themselves.

You will see trees being drastically reduced in height and also really compacted down into tight structures, it really is incredible.

If you know what you are doing, wire can really help you out when it comes to dealing with trees that are too tall.

(You can read more about – Frequently Asked Questions About – Pruning Your Bonsai)

Conclusion

As you can see there are a number of different ways you can deal with a tree that that is too tall, maybe you prune it back, wire it, or just leave it as it is.

What you decide to do will really depend on the tree you have in front of you, just weigh up all the options and think them through and I am sure you will pick the best option.

(You can read more about – How Long Will It Take For A Bonsai To Recover From Pruning?)