Why Has My Bonsai Lost Its Leaves?

I am often contacted by new tree owners in a panic asking why their tree has dropped all its leaves.

Often this panic is justified, but not always.

I will try and go through the common problems to try and help you work out what might be happening and if you need to do anything or if you should even panic.

Basic Questions To Ask Yourself About Your Tree

Firstly you need to know what species your tree is. This will make sure you have the right care instructions and can also ensure you are able to answer the following questions, which will hopefully help you work out why your leaves have fallen off.

Is Your Tree Deciduous?

If it is, then this is good. It is normal for deciduous trees to lose their leaves.

However, deciduous trees only lose leaves during the autumn and winter. If it’s the middle of the summer, this could be a problem.

If your tree is evergreen it should never lose all of its leaves. A few old ones may fall off here and there, but it shouldn’t be the majority of them.

Is Your Tree Inside?

Keeping a tree inside when it belongs outside can end in disaster. You will need to check your species to see what environment it should be living in. Chances are that keeping it inside is killing it.

One of the first signs that a tree is not happy with its environment is its leaves falling off. If your tree should be outside, then that’s where it needs to go.

Is Your Tree New?

If you have recently acquired the tree it may be suffering from moving shock. Some trees are very sensitive to having their environment changed.

If you have recently bought a tree it may just need time to settle in.

This can also be the case with trees that have been through the post. Being in a dark box for a few days isn’t ideal for them.

If this is the case they will usually start to bounce back with a few days and stop dropping leaves.

What Happened To The Leaves?

Asking some questions about how the leaves fell off can start to help you work out what might have happened.

Did They All Suddenly Drop?

This is normally a bad sign. It is usually from stress caused by a water issue, either too much or too little water. 

Did The Leaves Wilt Then Drop Off?

If they have wilted first, this is usually a sign of not enough water. You need to check and water accordingly.

Did The Leaves Turn Colour Then Drop?

This is potentially totally normal, especially if it is the autumn time. If your tree is deciduous, then this is fine. If its another point in the year, or your tree is evergreen, this may be a drought issue.

Are The Leaves Covered In Anything?

Insect attacks can cause real damage to a tree and can cause leaves to drop.

Check if the leaves are sticky or covered in any black residue. Also look on the underside of the leaves to see if you can see any insects. They can often be hiding on the underside of the leaves.

If you have insects, you will need to treat the tree to get rid of them. Depending on what incest will depend on what you should use.

You can start by spraying the tree with water mixed with a few drops of dish soap. Soapy water can usually deal with most things, but you may still need to buy a pest control product to fully remove the problem.

Is The Problem Happening Across The Whole Tree?

If the whole tree drops its leaves, this could be a problem and you will have to work out why this has happened.

However, if only one branch that is affected this may be a different issue. This branch has very likely been damaged and has now died back. I would still double check the rest of the branches, just in case it’s not something else and the problem spreads.

If only one leaf has fallen, this is probably totally fine. I would just keep my eye on the tree and double check everything, but more than likely this is totally fine.

Watering Can Cause Leaves To Drop

Your watering can have a huge affect on the tree. You need to ask yourself if you have missed any days, or if you have maybe watered too much?

You should also try and think about the weather during the last couple of days. Has there been anything out of the ordinary? Have there been any really hot days, or maybe super cold ones? This can affect the water needs for your tree so it could have caused the issue.

The Soil Can Effect The Leaves

How is your soil? Is water still able to get into the pot?

Sometimes when a tree is too pot bound it will start to struggle and become sick. Basically the water cannot get into the centre of the pot so it basically dries out.

You need to think about the last time you repotted the tree. This could potentially be causing the problem.

Can The Tree Be Saved?

If you think the leaves have dropped because of an issue, you will be wanting to know if the tree is going to bounce back and if the leaves are going to grow back, or if it is going to die.

At this point there is a chance it may already be dead, but we can check to see if it’s still got some fight still left in it.

Check The Branch Ends

Have a feel of the branch ends and any twiggy sections. If they are now very brittle or dried up looking this means that this section of the tree is potentially dead.

Bark Check

You can also check the bark to see if your tree is still alive. You can do this by doing the scratch test.

Make a small scratch on the bark of the trunk or branches. If it is green where you scratched, it is still alive and may bounce back.

If you find it is brown, it is most likely already dead.

What To Do Now?

If your tree is deciduous and its winter, just relax and care for it as normal until spring. Everything will be fine.

If you think you have identified an issue, try and correct what you have done wrong or counteract what has happened.  

The most important thing to do during this time is to NOT feed the tree fertiliser. This will kill the tree. You should never feed a sick tree.

You should then care for the tree as best as you can during the next few weeks. If you have corrected the problem and cared for the tree correctly, it should hopefully bounce back and you should see some new leaf buds after a few weeks.

While your tree is recovering, remember it has no leaves, so although it needs water, it might not need as much as normal.

Just check the tree everyday and make sure it is always damp and getting enough light.

Conclusion

Seeing your tree lose its leaves can be worrying but if you ask all the questions in this guide, you should get a better idea of what might have happened and then you can try and correct for this.

Hopefully you can save your tree, but it’s not always possible.

If this happens, try not to worry about it. It happens to us all and this probably won’t be the last time it happens to you.

You can only try and learn from the experience