Have you bought a bonsai tree or received it as a gift from a loved one? You might wonder, ‘how often should you water a bonsai tree?’. That was one of my first thoughts when I bought my first tree, and chances are that every bonsai artist has had that thought too.
If you don’t water it correctly, your tree will suffer or die relatively quickly, which will be noticeable. I’m here to provide you with the answer to this simple question: how often do you need to water a bonsai tree?
Bonsai trees are ordinary trees usually propagated from seeds, cuttings, or material transformed into a bonsai, such as from a garden center (known as pre-bonsai or nursery material). Bonsai is produced through constant, meticulous maintenance such as pruning, watering, feeding, and repotting.
Water requirements for bonsai trees vary due to the tree species, the temperature outside combined with the light intensity, the tree size, and the wind. The higher the temperature outside and the more intense the light, the faster your soil will dry out, which means that you might need to water your bonsai tree more frequently. If it’s pretty windy, this will cause water to be lost from the leaves, which again means you will have to water the tree more often. Smaller trees will require less water than larger trees.
This can be a bit to take in at first, but here are some tips on how often you should water the tree.
How Often Should You Water Your Bonsai Tree?
Don’t follow a routine!
Many people will automatically develop a routine for watering bonsai trees, which is a bad habit; you should only water your tree when needed. Don’t water your trees every set number of days – instead, check how dry the soil is before you water the tree. This will help massively in deciding how often to water a bonsai tree.
Ideally, the soil should be only slightly dry before you water it again. You don’t want the soil to be constantly wet, as this could lead to root rot which could kill off your tree. You also don’t want to underwater the tree, as this will kill your tree even faster.
I water my trees thoroughly for 10 seconds and then leave them for a minute, returning to water them for another 10 seconds. Doing this ensures that the root mass has received the water. While doing this, you should also check that the water is draining correctly. Ideally, the water should start draining out of the pot quite quickly – this is good as you don’t want the soil to be too water retentive.
Many bonsai bought from places that are not bonsai nurseries will come in quite a heavy soil mix, such as compost, which you should aim to fix in the repotting season (typically spring for most species).
If the soil is too water retentive you can fix this by poking some holes in it with something like a chopstick. In the long term, you should switch to a soil that drains better than compost. For example, Akadama is a good, versatile soil for many species of trees. However, you should research what mix you should use for the specific tree species, as this can help in deciding how often to water a bonsai tree.
For example, I like to mix 1/3 Akadama, 1/3 lava rock, and 1/3 pumice with Japanese maples. This is quite a popular mix for maples, and it’s been tried and tested to work! You can buy these soils from almost any bonsai nursery, whether online or in-store.
Check for signs of underwatering
When getting into bonsai, you should always check for signs of underwatering and learn how to recognize them if you need more clarification on how to water one or how much water a tree needs.
Some common signs of underwatering include curling leaves, usually brown at the tip or edge of the leaf, and yellowing leaves. Leaf drop may also occur early, which is another sign.
Underwatering can be fixed by adjusting how much water you’re giving the tree while also paying attention to the environmental conditions around you and the needs of the tree. However, if underwatering gets too bad, this can seriously damage the tree. Sometimes it won’t be recoverable, or growth may be severely affected next year. This is why you should definitely try and get as much experience as to how often you should water your bonsai tree.
It can also set your tree back quite a bit, especially if you need to do any major pruning. If your tree has suffered from severe underwatering, you shouldn’t prune it hard until it has fully recovered and looks healthy.
As mentioned before, the amount of water a tree needs will depend on the species of the tree, the intensity of the light, and the temperature. You should also note that trees will require less water in autumn, and you should reduce watering to around once a week in winter. However, you should constantly check the soil.
Check for signs of overwatering
What a lot of people neglect is overwatering. Most beginners will worry about underwatering, which can lead to them overwatering the tree. I’ve seen many a tree die from this issue. Gaining experience of how often you should water your bonsai tree normally starts with the death of at least one though!
Overwatering trees will cause harm to your trees, although it may take longer than underwatering trees. You must find the perfect balance between overwatering and underwatering for your trees.
To avoid overwatering, check how moist the soil is before you water the tree. If it’s still wet, you definitely should wait to water it. You should also take note of the species you are watering. Some trees, such as Junipers, can dry out a bit further than other species as they get most of their energy from their foliage which will benefit from misting.
In summer, I usually water my junipers around every two days. However, as I mentioned before I check the soil to ensure it’s not bone-dry. I typically water azaleas every day, and if it’s scorching on a particular day, I’ll water them twice a day.
Some common signs of underwatering are yellowing leaves and smaller branches becoming weaker. A less common symptom of underwatering, which is usually only noticed when repotting the tree, is the smell of the roots. When repotting the tree, if your roots have a pretty bad smell this could be because they are rotting due to too much water.
If you are overwatering your trees, this deprives them of oxygen, which will prevent further growth.Poke your finger in!
I know. It sounds weird at first. Just trust me.
If you want to check how dry your soil is, you should stick your finger in the soil about an inch deep. If it’s dry, you should give the tree a thorough watering. If it’s moist, hold off on watering. If you don’t want dirty fingers, you can also use a wooden chopstick for this instead. It won’t damage the roots if you do this.
This is one of the most helpful tips I received when I first started bonsai, and I can guarantee you that many bonsai professionals will still use this method. It’s an excellent way of determining how often a bonsai tree needs watering.
Invest in a soil hydrometer
If you don’t trust yourself to judge how wet or dry your soil is with your finger, this is probably the method for you, as it’ll give you an idea as to how often to water your bonsai tree.
Soil hydrometers will tell you roughly how dry or wet the soil is, allowing you to decide if the tree needs watering. Even though they may have a fancy name, they’re relatively inexpensive. You can find them for under £10 on many websites, such as Amazon.
I have never used a soil hydrometer before; however, I know a few people who do and don’t have any complaints about it. I prefer using my finger as it seems more accurate; however, feel free to use a hydrometer if you need to!
Find out about your tree
Pay attention to the fact that bonsai don’t have a specific amount of water they need. It will depend on the species of your tree, the size, the temperature, and the wind as to how much water your tree will require.
Some trees, such as wisteria, will thrive on much more water than others, such as junipers, so you should research online about how often to water the bonsai tree and how much.
So overall, what you should’ve gathered from this article is that how much water your bonsai tree needs depends on many factors. It depends on the temperature, light intensity, size of the tree and pot, wind, and tree species. Hopefully, all of your questions about how often to water a bonsai tree have been answered.