4 Important Things To Look Out For When Growing A Bonsai Tree

When it comes to growing bonsai, it can be really overwhelming looking through all of the information out there trying to find out how to keep your tree alive and well! When I got my first bonsai, I remember spending so many hours pouring through books and forums trying to figure out what I might have been doing wrong. In this article, I have aimed to put together the 4 MOST important things to look out for to keep a bonsai tree alive and growing!


The 4 most important things you are going to want to look out for when growing a bonsai tree the growing environment, efficiently watering, using the correct soil and repotting correctly. If you’re overlooking any of these crucial components, it could be fatal for your bonsai tree. Let me explain…

1. Growing Your Bonsai In The Wrong Place

There’s a very common misconception that bonsai trees are not like normal trees and are all just meant to be grown indoors, on a window. While some can be grown indoors, a lot of species will really struggle to say alive if grown indoors all year round. Bonsai trees require conditions that mirror the conditions the species would actually be getting if grown in natural, this includes sunlight, temperature and humidity.


No matter how on top of watering and pruning your bonsai tree you are, if your tree is lacking the sunlight it needs or it’s being grown in the wrong climate, it’s most likely not going to be healthy at all. It’s hard to put together a one size fits all style answer here as there are literally thousands of different trees used for bonsai, each one requiring slightly different growing conditions to the next. The best advise would be to research into your specific tree and see what conditions it’s best grown in. With some trees such as the Chinese Elm, you’re going to be able to grow that either indoors or outdoors, as long as the level of sunlight is still nice and high. Whereas with a species like a Crab Apple bonsai, if you tried to grow that indoors you would potentially kill the tree.

2. Not Watering Your Bonsai Properly

Watering is a hugely important part of keeping a bonsai tree alive and healthy, if not the most important of all! Although the process of watering is relatively simple, it’s still the main reason of bonsai tree deaths with beginners and much of the issues people have with their bonsai trees can be easily solved by watering correctly. The issues that come from a bad watering routine will range from leaves turning brown and dropping, to issues with photosynthesis and even root rot. This can be broken down into two main categories, either over-watering a bonsai tree or under-watering.


Whereas some new bonsai owners completely forget to water their new tree, some go completely the other way and water it constantly. Over-watering a bonsai tree is not strictly dangerous in the short term but if it continues over the longer term it’s deadly. Due to the soil constantly being very wet, the roots are going to start to rot and develop root rot. This is typically quite hard to notice until it’s too late and by that point the root mass is usually either dead or very infected – leading to the bonsai dying.


Over-watering can also be caused by the bonsai tree being grown in the wrong type of soil. I’ll touch on this more in point 4 of this article, but in essence, the soil needs to huge a very high level of drainage. Most cheap soils, not specifically mixed for bonsai, have really good water retention, which in our small pot can actually lead to root rot. Some people can be watering their tree absolutely perfectly for months and it will still perish due to the soil it’s sat in.


Another accidental cause of over-watering can be growing a bonsai tree in a pot that doesn’t have adequate drainage holes. Depending on where you got the pot or the tree from, some are just not sold with a drainage hole, as some indoor plants aren’t. This poses a huge problem for a bonsai tree as the roots are just going to be sat constantly in the water, leading to infection, mold and then eventually root rot. If your pot doesn’t have at least one drainage hole, preferably two, repot it to a more suitable pot.


Lack of watering is without a doubt the biggest killer of bonsai trees when it comes to beginners, mainly just from forgetting. Life gets in the way sometimes and watering your bonsai tree is the last thing on your mind, I get it but the bonsai is going to be a little less understanding. Bonsai trees are typically very thirsty, actually most of the year, not just in the Summer months. Watering needs to be done every day or every few days, all year round, the exact frequency changes based on a lot of different factors.


Bonsai trees live in a very small pot, which means they really don’t have much soil to work with. The small amount of soil, compounded by the fact bonsai soil drains very fast, means the tree is in need of constant watering. Symptoms of under watering will usually be the leaves starting to drop off, turn brown or go quite dry and crispy.


Some species of bonsai can tolerate under-watering better than others but it should be avoided as much as possible by implementing a daily check of the soils moisture levels. If you miss a day every so often, providing it’s not during the hottest days of the summer, your tree will most likely not be too badly affected. You need to aim for consistency, not perfection when it comes to watering a bonsai tree – under-watering as little as possible. If you’re going two or three days without checking to see if the tree needs watering, you should check out my article detailing how to perfectly water a bonsai tree.

3. Not Repotting A Bonsai Frequently Enough

Bonsai trees need repotting fairly frequently as they eventually outgrow their current home. As a bonsai tree grows, the roots are of space to grow and they are going to become extremely compact. Roots are also going to start trailing out of the pot into the humidity tray, which will cause those roots to actually rot from sitting in water constantly.


The time of year and exactly how long to repot is species specific but a general rule of 2-5 years is about right for most common trees. The quality of the bonsai soil will also start to break down after this length of time, especially if you’re using an organic mix, meaning the soil is going retain a lot less water and nutrients – making it harder for the tree to thrive. If you’ve had a bonsai tree for over 3 years and haven’t re-potted it yet, it’s definitely time to get that ticked off.

4. Using The Wrong Bonsai Soil

Not a lot of bonsai newcomers know this but a bonsai tree is not actually going to survive in just a normal soil, such like you would find in your garden. In fact, the soil a bonsai is grown in, is without a doubt one of the most important but one of the most overlooked factors in actually keeping the tree alive and thriving.


If a bonsai tree is put in normal soil it will die as normal soil doesn’t have good enough drainage, it simply retains too much water. The higher levels of water sitting in the soil after watering is going to cause what’s known as root rot. Root rot is typically hard to detect until it’s too late and the whole tree is rapidly dying as the root system is completely useless. So to keep a bonsai tree alive, it needs to be grown in what is known as bonsai soil.


Bonsai soil is normally comprised of Akadama, Lava Rock and Pumice, all working together to create the perfect mix of water retention and drainage. The soil needs to retain enough water to keep the soil moist until the next watering, yet have enough drainage to ensure it doesn’t stay waterlogged, which will soon cause root rot. A good bonsai soil will also allow tiny air pockets to be created in the soil, as this will help oxygen reach the roots. Many bonsai enthusiasts don’t trust shop bought soil and choose to mix their own ratios for their trees, depending on the species. I have put together a guide on creating your own bonsai soil, should you be interested.


If you are buying a cheap bonsai tree from the internet, it might be in your best interest to repot it with bonsai soil as soon as you can as most low quality trees are just mass grown in potting soil as the longevity of the tree is rarely considered by large scale grows.

Conclusion –

Looking after a bonsai tree is really simple once you have the hang of it but learning the tips and tricks to keeping it healthy in the first few months can be hard! In this article I’ve aimed to cover the most common yet overlooked problems that newer bonsai owners tend to run into, that could save a tree or two. Of course I haven’t managed to cover all of the important things to look out for when it comes to cultivating bonsai as there really is a lot of them but hopefully this will be enough to get a few readers out of trouble! Drop me a comment below if you have any questions about anything covered in this article!

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