Repotting Aftercare Advice For Your Bonsai

Repotting a bonsai is something you are going to have to do at some point. It is a vital part of growing a tree in a pot and you need to do it to keep them healthy.

(You can read – When Should You Repot A Bonsai – for more information)

Repotting is quite a traumatic experience for a tree. Usually they grow in the ground and never move. It’s not exactly natural for them to have all the soil removed from their roots and then have them chopped back. However, as I’ve already said it is vital work for bonsai and it is also very safe if done right.

A large part of how successful your repot will be comes down to the aftercare you give the tree.

The amount of aftercare that is needed will depend on the species and also how hard you worked the tree during the repot.

Some species are very delicate and hate root work, other trees don’t even notice it’s happened, but even if you smash these types of trees back to almost zero roots, they will still need a little help recovering, so it is always good to make sure all your bonsai trees get good aftercare when you repot them.

The Timing Of The Repot Will Determine Aftercare

The time when you repot is going to play a huge role in how much aftercare you need to give you bonsai tree.

If you time things right, your tree will barely notice anything has happened and you won’t need to do much aftercare. If you get the timing wrong, your tree can severely suffer and you may find good aftercare is the difference between life and death.

You need to be repotting in spring. You will see the new buds starting to swell and the best time to do the work is just before these buds open.

It will depend on the species, but normally you can be a few days late or early and it should be okay. The real trouble comes when you get this timing really off, like you do it in the middle of summer. This is really going to require a lot of aftercare and even then it may be too much stress for the tree to handle.   

Watering A Bonsai Properly Is Important After A Repot

How you water your bonsai after repotting is probably the most important thing when it comes to aftercare.

You need to get this right or you tree really will die very quickly.

It is so important that I have written its own separate guide for this – How To Water After Repotting, which you should read after you’ve finished reading this article. 

Light Levels Are Important After Repotting A Bonsai

Light is also extremely important for a bonsai tree and for most of us it is something we do not need to worry about. The sunlight in spring is usually not great, which is perfect for a recovering tree.

If you do live somewhere where it is a little too sunny, or maybe there are a couple of very bright days then you should move the tree and try to keep it slightly shaded.

As the bonsai tree opens its leaves and starts growing it is going to start trying to draw water up from the roots, which is going to be pretty difficult to do if you have removed a lot of them during your repot work.

The stronger the sunlight, the more demand it will put on the leaves and the roots, which just won’t be able to handle it.

Shade will easily solve this problem and keep everything relatively calm for the first few weeks and will give the tree time to recover. 

Temperature After Repotting A Bonsai

This is another thing that we cannot directly control, but we may have to move the tree to overcome it. 

Usually in spring as the buds are opening the risk of frost should have passed, but not always.

If you have repotted a tree and you see some cold nights are coming, you need to move the tree to somewhere it will be protected.

If it goes below freezing your tree will probably die. Freshly cut roots and frost do not mix well.

If for some reason it gets extremely hot after repotting, you should also move the tree somewhere it can be a bit cooler. Roots grow best and recover in a nice warm environment. Being too hot or cold is going to upset them too much and cause the tree to die.

Being warm would suggest that somewhere like a greenhouse is going to be best, which is probably true, but I know we do not all have access to this.

For most of us the spring weather is mild enough for the roots and they will be totally fine outside, then if for any reason that changes, you can try and shelter the tree until the extreme temperature passes. 

Really you should check the long range weather forecast just before you repot. This might alert you to some future trouble and it might be better to delay your repot until after this has passed, rather than trying to battle through and have to protect the freshly repotted tree. 

Try To Keep Your Bonsai Out Of The Wind After A Repot

Wind is big trouble for two reasons.

The first issue is that a freshly repotted tree is probably pretty unstable in the pot. You may have wired it down, but that is still not perfect.

It is very easy for wind to knock the pot over, blow fresh loose soil out of the pot, or just blow the whole tree out of the pot. This happens to me all the time as I am stupid and never tie my trees in. I just never seem to learn!

Any sort of small movement can also very easily upset and even damage the new delicate roots, which is not what you want.

Secondly, wind can dry out your pot faster. This shouldn’t be too much of a problem as you should be checking your pot every day to see if it needs more water, but it is still something to be aware of.

You should be trying to keep your tree out of the wind for the first few weeks, really until you see some good strong growth on the top, which should mean the roots are also growing strongly and the tree is starting to grip itself into the pot.  

Give Your Bonsai Shelter After A Repot

You’ve probably worked out from reading the above points that some shelter is going to be the best way to care for a tree after repotting. You can control the water, the light level and prevent wind.

The best type of shelter is going to be a green house or a poly tunnel. They are warm and humid which is just perfect for root growth.

However, it’s not always necessary. I’ve done hundreds or repots over the years and I’ve never used a greenhouse.

I think it would be a very good addition and something I want in the future, but really if you time everything right and just place your trees in a good position after the repot, you should be fine without any real shelter.  I usually keep my trees next to a wall and this gives them enough protection.

Fertilising A Bonsai After A Repot

This is something you need to stay away from. DO NOT fertilise your bonsai after a repot.

Fertiliser it’s not “food” that will make the tree get stronger. It is just chemical compounds that the tree can absorb to help it grow better … but when it has damaged roots after you have pruned them, this is not what it needs.

Adding fertiliser to freshly cut roots will actually burn them and damage them even further, potentially killing your tree. So no fertiliser until the tree has recovered and is actually growing again.

(You can read more about – What Are Some Common Mistakes To Avoid When Repotting A Bonsai?)

Rhizotonic Is The Best Afercare For A Repotted Bonsai

This is the secret weapon! This is what you need to use. Rhizotonic is the best aftercare for a repotted bonsai.

This magic liquid is designed to help heal the roots and helps with stress and shock, which your bonsai tree will defiantly be in.

If you live in North American there is a product called Super Thrive. I’ve not used it, but apparently it’s very, very similar to Rhizotonic, so you can use that instead.

It is very important to note that this stuff is not fertiliser, so don’t get the two confused. Rhizotonic is basically made from algae and promotes new roots and healing, which is why it is the secret weapon of repotting aftercare for any bonsai.

(You can read more about – Using Rhizotonic On Your Bonsai)

Conclusion

Repotting is tough on a bonsai tree, but so long as you do everything right and you take the time to look after the tree properly afterwards, you should not have any problems.

It really is about common sense and keeping things simple and your tree will recover and will be back to growing strongly in no time.

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