If you’re new to bonsai trees and want to take care of your own, you must learn how to water it properly, so here are all the ins and outs according to what we found.
On average, most bonsai trees require to be watered on average 3-4 times per week, however, there are other important factors you should consider like tree species, time of the year, soil mixture, climate, etc.
Learning how to water your bonsai tree is one of the most important parts of taking care of your bonsai tree. But don’t worry, we will cover the most important questions regarding bonsai tree watering every amateur bonsai owner must know.
So, how often do you water a bonsai tree?
The short answer is: it depends. Every bonsai tree is unique, in terms of shape, species, climate, latitude, etc., in reality, you should water your tree as often as it needs. Here is how you know when that is :
If the soil gets slightly dry, water your bonsai.
In a nutshell, this technique should be your guide to watering trees.
The process is simple: stick your finger in the soil around 0.3 inches or 1 centimeter deep and feel how the soil feels. If it feels wet, then don’t water it yet. If it feels slightly dry, then do it right away.
Why 1 cm or ⅓ inch deep? Because the roots will most likely be concentrated at the bottom, and you need to make sure that the soil is wet all the way to the bottom.
Remember, just don’t let your tree dry out completely.
Don’t water routinely
Time isn’t your friend. Don’t water on a clock, don’t water with an alarm. Bonsai trees will tell you when they need water through their soil. So as a rule of thumb, observe them constantly, check them routinely and water when it is needed.
We like to check our bonsais in the morning, and in the evening, generally once is enough in our case. If you see the soil and it looks dark, and feels moist, then it does not need any water.
If, on the other hand, the soil looks light brown, and feels even a tiny bit damp, add more water to your bonsai.
When should you water your bonsai tree?
The exact time you water your bonsai doesn’t have a large impact on your bonsai’s health. As a rule of thumb, you should water your bonsai as soon as you feel the soil getting too dry, regardless of what time it is.
But, what we’ve found is that most expert bonsai keepers, avoid watering their bonsai at the hottest time of the day. During this time of day, water can evaporate in an out of the ordinary way, and cause your tree to dry up more unexpectedly. Also, if there are drops of water on the leaves, these can act as magnifying glasses, and end up burning your leaves.
So, as a rule of thumb, it is best to water your bonsai during the morning, or afternoon.
The hot summer days can be more troublesome for your tree, since they can result in quicker drying up of your soil. If this happens, you’ll notice your soil will become hard. So if it does, then submerge your bonsai in water, cover the surface and let it be for 10 mins approx.
During winter a bonsai need less water. However, if you have an indoor bonsai tree, the central heating system of your home might dry it up without you noticing. A quick way to re-humidify your bonsai, is to place your bonsai on a tray rocks to hold up your bonsai filled with water. As the water evaporates, it will create a nice, humid environment for your tree to thrive.
Is your bonsai dehydrated, overwatered or underwatered?
The most common reason why bonsai trees die is due to underwatering. The reason is simple. Since the pot is small, the soil layer is shallow. Since it’s shallow, it’ll dry out quickly. As a rule of thumb, try to water as soon as you see the soil seems dry, which can mean once per day.
To make sure you water properly, add water until it comes out from the draining holes. It’s also smart to add a tray to collect the remaining water. But be careful, if you see that your tray is filled with water or your tree is standing in water, the roots will quickly rot.
Ideally, you should touch the soil always, but if you start seeing the following symptoms on your tree, then this means your tree might be too dry. The first and most common, is the leaves becoming crispy and dry and start to fall off.
If your tree has suffered from dehydration, then simply submerge its pot and soil for about 10 minutes and re-wet the soil evenly.
But, be careful and avoid over-watering during this time period. It can be tempting to want to give more water than what it might need, so you need to be patient as it could take from 4-6 weeks before your bonsai looks alright again. Since it would likely have less leaves (since they’ve fallen), then a dehydrated tree needs a bit less water than a healthy tree.
On the flip side, overwatering is another reason why bonsai trees die. If the roots of your tree have too much water, they’ll start drowning, which will, in turn, prevent oxygen to continue its natural growth.
Unlike wild trees, bonsai trees are grown in small bonsai pots, which mean they have less soil to work with. This means that bonsai trees will dry out more quickly than trees planted on the ground.
Most causes of overwatering come from a poor drainage system in the soil of your bonsai tree and come down to its roots becoming inefficient in transporting water up the tree. However, it can be a bit tough to identify how much is too much, or how often is too often, but you can notice some symptoms in the tree itself, when your tree might be overwatered.
The first is when you notice the leaves turning yellow, the second most common being when your branches start to shrivel. An overwatered bonsai can also look wilted, and have black tips on its leaves.
Cool trick: Submerge the pot
If you want to make sure that everything is covered, then simply submerge the pot in a bowl of water and leave a few minutes.
Considerations When Watering Your Bonsai Tree
These are some factors you should keep in mind when finding out how much water your bonsai tree needs: size, pots, soil, and location.
Consider the Size of the Tree
Contrary to what you might think, a smaller tree might require more water than a larger tree. The trick is, not to think in terms of tree size, but of pot – soil – and roots size.
Unlike wild trees, bonsai trees are grown in small bonsai pots, which means they have less soil to work with. This means that bonsai trees will dry out more quickly than trees planted on the ground.
If your tree has too much root concentration, then there won’t be enough soil to hold the water, meaning you’ll need to repot it. In any case, make sure you water it completely, and make sure that the entire root mass is completely wet.
Remember that bonsai trees behave the same as normal wild trees. Meaning, they receive the water from the soil and pump it up through the roots to the foliage. Enough water is needed to make sure it can reach all the leaves from the tree.
Consider the Soil
It’s important to remember that your soil mixture will impact how often your bonsai tree should be watered. For instance, if you use more akadama in your soil mixture, this will cause your tree to retain more water, so you can water it less frequently.
Consider the Location
Temperature will have an effect on how much water your bonsai tree needs. If you live in a warmer climate, the tree will need more water to support the entire system before the water evaporates.
If you live in a windy place, your tree will lose more water through the leaves. In the summer you’ll probably need to water your tree almost every day.
Outdoors vs Indoors
Don’t hose your pot. This can disrupt the soil, roots and even damage the tree. In general, this advice goes for outdoor bonsai people. Outdoor bonsai people don’t care about watering getting everywhere, inside, people do care. So in short: don’t use a hose.
In general, outdoor bonsais will be better off since they are in a more natural environment. On the flip side, indoor bonsais are in a more artificial environment, but the same principles apply. Routinely check the soil and you should be good to go.
How to water your Bonsai tree?
Remember you should only water your tree once it feels slightly dry. If this is the case, then try to soak it in its entirety, including all roots, and all root systems.
You’ll be able to tell, since water will start coming out the bottom drainage holes. Then pause, and do it once again a few minutes later.
How much water should you use to water your bonsai tree?
Instead of watering or sprinkling, it’s best to think in terms of soaking.
Water when you see that it looks dry. Water until water comes out from the drain.
What is the best position to water your bonsai tree?
There are two basic methods for watering your bonsai, overhead and immersion method. We recommend the overhead method, since it’s the most sensical and simple for beginners like us.
The Overhead Watering method is, as you could imagine, watering from above. This way, you’ll be able to cover the entire tree and make sure that all the roots are covered. Avoid using a strong spray of water, as it can dislodge the soil and damage your root system.
If water puddles in the surface of the soil, then wait a couple of minutes, let it drain into the soil, and water again. Keep going until water comes out from the bottom, that’s when you’ll know when to stop.
The Immersion Method is one of the most popular and cost-effective methods there are, especially for indoor bonsais. Simply fill a sink of water, up until it could cover your bonsai up to its trunk. Then, submerge your tree for a couple of minutes.
Then, water bubbles will start to come out from the soil. These bubbles can tell you something about how much water you need. If there are too many bubbles or if they come up too slowly, then you are not watering it enough. Once the bubbles stop, then it’s time to stop. Remove your tree, and allow it to drain.
What is the best type of water to water your bonsai tree?
All natural is better. This means that if you can, collect rainwater as it avoids added chemicals – but remember to keep tabs on when you gathered it first. If rainwater isn’t available, normal tap water will also do the trick, so don’t worry.
As a rule of thumb, if you can drink the water, then you can use the water. If you have hard tap water, like in Europe, (water that leaves white marks), you may want to use rainwater.
Do I need a bonsai watering can?
In short, no – you don’t need one. But, it is a good investment to make. Especially, a watering can with a fine nozzle and a fine spread. This will prevent the water pressure from being too strong and moving the soil and disturb the bonsai tree. The most important thing to notice is the strength of the water that comes out.
As a rule of thumb, try to avoid having too much water come out and try to mimic rainwater, as its the most natural for your tree. You’ll often find these as “rosettes” or brass rose spout watering cans.
One of the best watering can that most experts agree upon, is the Haws English watering can:
How to water your bonsai If you’re leaving for a few days (vacations)
Well, it depends on how long you are leaving for. If you’re leaving for only a few days, then you’re probably good. Bonsais can get a bit dry, but avoid them completely drying out. But it’s important to remember, bonsais aren’t your normal house plants and they won’t become healthy with a quick splash, so try your best to avoid them drying out.
If you’re leaving for longer than a couple of days, then ask a friend or neighbor to water it occasionally. Or, you could buy a bonsai dripper, which basically is a slow drip or trickle of water which avoids your bonsai to ever completely dry out. But limit this dripper to a week, not more than that.
A more do it yourself (DYI) approach could be wrapping a plastic bag around the soil and leaves and closing it with a wire. This will prevent water from evaporating and will keep your bonsai more humid than it would in a normal environment.
In any case, it’s a good rule of thumb if you can keep your bonsai away from the sun during your holidays, so during this time, use a bright light and a place where it will stay cool.
If you want to be serious about bonsai and bonsai care, you need to know how to water it correctly. It can seem more complex than it really is, and there might seem more information than what you might have expected, but in reality, it’s simple: check your bonsai regularly by sticking your finger in the soil, and water it if it feels dry. That’s as simple as it gets.