What Is The Growth Rate Of A Bonsai Tree?

Knowing the growth rate of a bonsai can be hard as no two trees are the same. They all have different ages, sizes, health and will be at different stages of development, as well as the fact they can be different species.

This along with various external factors can really change the rate at which a bonsai tree grows, which makes it very hard to give a straight answer.

Your bonsai may grow anywhere from a few centimetre to a couple of meters a year. There is no average amount, it will really just depend on what you are working with and what you are doing with it.  

What Affects The Growth Rate Of A Bonsai?

I will go through some of the factors below, which will give you an idea of why it is so difficult to say what the growth rate of a bonsai should be. All these factors can vary, meaning a tree I own may not have the same results as a tree you own. 

The Species Of A Bonsai Affects The Growth Rate

There is an endless number of species that are used for bonsai and some are a lot more aggressive growers than others.

I have a quite a wide number of different trees and you can really see the difference between species.

You might also find that different varieties of the same species grow at different rates. This is really noticeable with variegated varieties. Basically they have less chlorophyll in their leaves, which means they cannot photosynthesise as much as a non-variegated version. This means they are not producing the same amount of food, so they grow more slowly.     

The Age Of A Bonsai Affects The Growth Rate

The age of a bonsai tree will also affect its growth rate. A younger tree is going to grow much faster and more aggressively than an older tree.

If you look at trees in general you can see this happen. A seedling will put on some serious growth for its first few years until it reaches roughly full size.

You can literally see the change over the season. However, once it reaches a certain point it almost looks like it stops growing. The tree just kind of stays the same size year over year. It will be growing, just at a much slower rate. 

(You can read more about – How Old Is My Bonsai Tree?)

The Size Of A Bonsai Affects The Growth Rate

The size of your bonsai will also come in to play. If you have a super small mame that is only a few centimetres in size, it is probably only going to grow a few centimetres a year.

If you have a tree that is a little larger, say a meter tall, it is going to be able to put some seriously long growth if you let it grow wild for a while. You might find that a shoot can easily reach a meter long.

This just basically comes down to mass. A bigger tree is going to have more energy in it, so it going to be able to grow more aggressively than a tiny little tree.

(You can read more about – What Size Should A Bonsai Be?)

The Health Of A Bonsai Affects The Growth Rate

The overall health of your bonsai is going to play a huge role in its growth rate. A happy and healthy tree is going to grow a lot more than a tree that is struggling with its health.

If you keep your tree at optimal health it will reward you with optimal growth rates.  

The Climate Of A Bonsai Affects The Growth Rate

When I refer to the climate I mean the light levels, temperature and water levels. Some of these you will have to control, such as the water, where as the light and temperature are pretty much out of your hands.

You can also control these, but it is a lot of work and you are better to just to leave it to nature to deal with these.

Where I live is quite mild. My bonsai trees grow well, but I know if I took them to the south of France for example they would just grow so much more aggressively.

The quality and amount of light there is much higher and the temperatures are a lot warmer down there too and it would dramatically change the rate of growth for my trees.  

As I said, you can’t really control these, but it is something to bare in mind, especially if you are looking at someone’s trees online and wondering why their growth rate is so much better than yours. It mostly likely that they just have a better climate that is more suited for growing trees.   

The Condition Of The Soil Affects The Growth Rate Of A Bonsai

The quality of your bonsai soil will play a huge role in the growth rate of your trees. The roots are like the engines of the tree, so if you have good soil, you will get good growth.

Roots need water and oxygen and good free draining bonsai soil is going to offer a good supply of both of these to the tree. Simply put, the more water and oxygen a tree can have access to, the more likely it is growing to grow at a much stronger rate.

(You can read more about – A General Guide To Bonsai Soil)

Fertiliser

While water and oxygen are the main things a tree needs, it also needs plenty of micro nutrients. Using fertilisers can make sure the bonsai tree has the optimum amount of these, which will help it grow faster.

Fertilisers that are rich in nitrogen are going to be able to speed up that growth rate and give the tree a little extra boost.

(You can read more about – Do You Need To Use “Bonsai” Fertiliser?)

The Size Of Pot Affects The Growth Rate Of A Bonsai

While the soil itself is important, how much soil is available for the tree will also play a role in its growth rate.

Basically the more soil, the more space the tree will have to grow as well as more access to the water and oxygen it needs to grow.

This is why you are supposed to start your bonsai in larger pots. This will get them to develop a lot faster and as they start to get more towards the size you want them to be, you can start to slow their growth rates down by reducing the amount of soil (in a smaller pot), which of course lowers the amount of available water and oxygen.

This is also why growing a bonsai in the ground is going to give you the biggest growth rates, as it basically has unlimited access to what its needs and space to grow in to.

(You can read more about – How and Why To Grow A Bonsai In The Ground)

How Often You Prune Affects The Growth Rate Of A Bonsai

Pruning your bonsai tree will affect its growth rate. If you want it to grow faster you need to leave it unchecked. Removing the terminal buds is going to slow things down.

This can be both good and bad. Initially it is going to change the rate of growth and slow it down. The tree is going to end up sending hormones back down into the tree after you prune it, which is going to encourage back buds to grow.

Pruning usually balances the vigour of the tree, but more importantly when it does start growing again, there will now be even more shoots than before. If you leave these for a while they can all start to pick up speed and you may find that actually the growth rate increases.

This is of course a long game. You may not see this increase until the following growing season, but bonsai is all about the long game, so you should get used to playing it.     

You are also going to have to prune your bonsai tree at some point. If you just leave it, it will eventually turn into a full size tree.

Grow Rate Of Bonsai Can Change

It is also important to understand that the growth rate of a bonsai will always be changing.

As the months of the year pass, you will see your bonsai grows faster and more aggressively at certain times compared to others (They usually grow fastest in spring and of course do not grow at all over winter). This can also be true from year to year. A bonsai may have a better growth rate one year to the next.

As you can see from above there are a lot of factors that can affect the growth rate of a bonsai and any minor changes in any of these can have a compounding effect and cause your bonsai to grow more or less than it would have previously.

Can You Measure The Growth Rate Of A Bonsai?

I guess in theory you can measure the growth rate of a bonsai, but what are you going to do with this information?

Just because your shoots grew 5cm in one month this spring, does not mean they will do the same next year. Even if you keep the conditions identical year to year, you will not get the same growth rates.

You are much better off just making sure your tree is healthy and providing it with the optimum conditions and just allowing it to do what it can. Over the long term its growth rate does not matter, but its health does.

(You can read more about – What Stage Of Development Is Your Bonsai Tree At?)

Conclusion

As you can see there are a lot of different factors that can affect the rate of growth of your bonsai. This means if you change any of these, even slightly it can dramatically change how quickly or slowly your tree grows and therefore it is impossible to know the growth rate of a bonsai.

You should just stick to the basics and try and keep your tree healthy. Make sure it is in good soil and well watered. It will grow at the rate it wants to, you can’t force these things. Give it time and be patience. it will grow and it will develop how you want it to. 

(You can read more about – How Long Does It Take For A Bonsai Tree To Grow?)