Bonsai Watering Guide: How To Water Bonsai Trees Properly?

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How to water bonsai trees properly is a very common question among bonsai growers. So, in this post, we will be going to address this. We will discuss various methods of watering a bonsai tree. You will also learn about bonsai immersion watering.

Bonsai trees are miniature versions of the actual trees so most of them are quite delicate and need proper care.

One of the most difficult parts of bonsai tree care is keeping a bonsai tree properly hydrated. Too little water can leave your bonsai shredding leaves, and branches, or even die whereas a little too much of water and the roots start rotting.

Watering a bonsai is a little bit different from watering your regular houseplants. This is because bonsai are different, they have small, confined root systems and need to be watered more frequently. So it is crucial that you learn to gauge the watering need of a bonsai tree.

How Often Do I Need To Water Bonsai Plants:

As they are planted in coarse soil and shallow pots, a bonsai can dry out quickly. So they would need watering more frequently. You rarely can follow any single watering schedule for your bonsai.

There are many factors that will determine your watering frequency. Some of the factors that affect how often you will water bonsai plants are:


The soil of the bonsai has many components. Some of them can retain water quite well. If your soil mix has clay, peat moss, or vermiculite in it your watering frequency will reduce as these ingredients will hold on to the water for a longer period of time.

Now before you get excited and start increasing clay, moss, or vermiculite in the soil mix remember, too much of these components can also harm your bonsai. Anything more than 25%, and you risk root rot.


Fertilizers increase the nutrients in the soil and promote the growth and health of the bonsai. But by affecting the growth rate of a bonsai tree they also dry out the soil faster.

Container Size:

The bigger the pot, the larger the soil volume. More soil means you have to water less frequently. Small containers dry out faster than larger ones.

Plant Type:

The size of your bonsai tree affects how often you need to water it. If your bonsai is the size and type of plants can affect the way you water your plant.

A larger, fast-growing bonsai can dry out the soil quickly. On the other hand, a tiny bonsai will bother you less with her watering needs.

Availability of Sunlight:

Sunlight increases the rate of photosynthesis and transpiration in plants. So when the bonsai is under the direct sunlight you will have to water your bonsai more frequently.

Ideally, bonsai grows fastest when the light is bright but the temperature is not very warm. But when you put the bonsai under direct sunlight, it also increases the temperature, especially in tropical summers.

When you place your bonsai tree in a shaded area you are reducing the growth rate. To counter this problem you can use grow lights that will give your plants direct light without increasing the temperature much.


Wind can affect how frequently you have to water your bonsai. It increases the transpiration rate and decreases your bonsai plant’s watering interval.

Strong winds, especially in winter, can rapidly dry out bonsai trees. If that is the case, you have to water your bonsai through continuous watering in the winter.

This may also vary as per the type of plants. Some plants and trees are more vulnerable as compared to others.

Temperature and Humidity:

High temperatures can increase transpiration and reduce the drying time of the soil. If you live in a tropical area you will have to water more frequently than if you live in a colder region.

Bonsai trees thrive with higher humidity. High humidity also decreases the transpiration rate. So you will have to water less frequently. Increase the humidity levels with the help of a humidifier like this to extend a bonsai’s watering cycle, especially if you live in a hot, dry climate.


Watering frequency depends largely on seasonality. Like during summer watering twice a day is a normal phenomenon. while during winter once a week is the standard. Apart from these two extremes once a day is quite normal for most of the seasons like spring or autumn.

Having said that sometimes you might have to water it 3 times a day or once a month. It depends on your judgment of plants’ water needs.


Bonsai diseases can impact the watering schedule of the plant. A disease like root rot decreases water absorption and increases the drying time of the soil.

It might take you a few weeks to really observe and become familiar with your bonsai and its watering needs.

Signs of Under-Watering A Bonsai Tree:

Unlike traditional trees that grow outside, bonsai can not regulate moisture exposure. The bonsai soil is also less stable than the soil present in the ground.

As the soil dries up pretty fast, underwatering a bonsai tree can be fatal. As the pot is significantly smaller than any traditional growing pot, you have to ensure the plant gets a continuous flow of water to continue its biological processes.

A simple way to find out if your bonsai is not getting enough water is to look for some common symptoms. A water-deprived bonsai will show yellowing or browning leaves or the leaves may dry up. You will also find the soil of the container is totally dry.

Signs of An Overwatered Bonsai Tree:

The effects of overwatering can take a longer time to appear. When if you overwater your bonsai, it creates a permanently wet environment for the bonsai root system. This excessive water creates a hindrance to airflow in the soil. Airless soil suffocates the root and eventually the roots die.

Some common signs of an overwatered bonsai tree are:

  • The foliage starts to turn yellow and drop.
  • The smaller branches may shrivel.
  • The stems can die back.

The problem of overwatering is easy to solve. Focus on the soil components. If your soil has a good drainage capacity it is almost impossible to overwater it. Poorly drained soil is the number one reason for root rot disease in bonsai.

How Do I Know When My Bonsai Needs Water?

This has a simple answer, feel the soil. Stick your finger into the soil and if you don’t feel any moisture there, you have to water the bonsai.

You can also chopsticks in place of your fingers to find out the moisture level in the soil.

A professional way of doing this would be to use a Soil Moisture Meter like this. It will cut the guesswork out and will give you the exact moisture level near the roots.

Where To Water A Bonsai Plant?

Water the soil, with a sprayer apply water to the leaves. To prevent any root damage during watering, use a hose attachment. It would dispense the water softly without disturbing the roots. Use a sprayer to water the leaves.

How to Water Bonsai Trees

The two major bonsai watering methods are overhead and immersion.

  1. Overhead bonsai watering
  2. Bonsai immersion watering

1. Overhead Watering Method:

This is the most common way of watering a bonsai plant. As the name suggests here, you give water to your plant from the top down.

In the overhead watering method, begin watering your tree from the top, be careful not to disrupt the soil surface too much. Keep watering till you see water coming out of the pot through the drainage holes. You can use a tray below to catch extra water so it doesn’t damage your furniture.

Overhead watering can be of many types. Here are some different variations in overhead watering methods:

Watering By Rainfall:

This method involves the simulation of natural rainfall. It is an old practice from Japanese bonsai care. First, soak the soil till the water runs out of the drainage holes.

Wait for 20 minutes and let the water soak the soil. After that soak the soil again once again till the water runs out of the drainage holes again.

Using Watering Cans and Hoes:

 how to water a bonsai tree

In this method, you can use a fine nozzle, a watering can, a garden wand, or a hose, and gently shower water over your tree.

Make sure the water flow is not too strong, otherwise you would damage your bonsai. Use a small watering can that is fitted with a fine rose. It helps water the soil without displacing it.

Drip Irrigation:

A drip irrigation system is also useful for watering bonsai plants. A drip irrigation system can be both manual and automatic. Choose the one that suits your needs.

If you have plenty of bonsai trees an automated irrigation system will save you a lot of time and energy.

Self-Watering Containers:

You can also use self-watering containers to water your bonsai trees. It is a very clever choice. A water saucer works as a self-watering container that waters your precious bonsai plants when you go on a trip.

2. Immersion Watering Method:

Alternatively, you can do bonsai immersion watering, i.e, submerging the bonsai soil in water. Unlike overhead watering, bonsai immersion watering is a bottom-up process. Here is what you need to do:

  • Fill a bucket with water up to a height where it reaches about one inch up the trunk of your tree.
  • Submerge your tree in the water. You will see bubbles as you dunk your tree. A lot of bubbles generally means your tree is very dry and needs a lot of water.
  • Keep your bonsai in the water until there are no more bubbles in the water. No more bubble means there is no more space for water to enter the soil and the roots are fully hydrated.
  • Take out the bonsai from the bucket the allow it to drain. Sometimes you may lose some soil in this method so keeping some extra soil will always be handy.

This method of immersion watering works best when a bonsai tree is completely dried out. But don’t use it too frequently, frequent water immersion can also cause root damage.

Green Moss Watering For Bonsai:

Planting moss in the bonsai pot actually works very well for bonsai plants. It helps to keep the water inside and prevents faster drying out of the soil.

Due to the presence of moss, it generally takes more time to absorb water; so you have to add plenty of water to get it enough into the soil. Green moss can cause the water to run off over the edge of the pot. It can also act as a coating.

What Kind Of Water Should I Give My Bonsai Tree?

You can use regular tap water to water your bonsai trees. Generally, tap water has lots of chlorine in it. So prior to using the water, let it sit in a bucket or water cans for 12 hours; this way chlorine will evaporate and you will have clean water to water your bonsai.

You can also collect rainwater and use it to water the bonsai. Rainwater will also remove any excess salt from the soil.

Watch Soil Color Before Watering:

Watering a bonsai plant is a tricky business and it will take time for you to be good at it. It is said that you need to spend at least 3 years to become a master at watering bonsai. The soil color and condition represent a lot of facts in bonsai.

Watering bonsai trees is an art, but once you’ve got the hang of it, it can be extremely rewarding. I hope this post helped you understand how to water a bonsai tree properly. You can learn more free stuff on bonsai gardening here.

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