How to Water an Indoor Bonsai Tree: Expert Tips and Techniques

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If you’re new to the world of Bonsai trees, you might be wondering how to properly water them, especially when it comes to Indoor Bonsai Trees. Overwatering or underwatering your Bonsai tree can lead to its demise, so it’s important to get it right. In this blog post, we’ll provide you with simple and effective tips on how to water your Indoor Bonsai Tree correctly, ensuring its health and longevity. Get ready to say goodbye to wilted and thirsty Bonsai trees!

Essential Supplies

When watering a bonsai tree indoors, it’s crucial to have the right supplies to ensure your tree receives proper care. This section will discuss three essential items: a watering can, a spray bottle, and a tray.

Watering Can

A quality watering can should be used for effectively watering your indoor bonsai tree. Opt for one with a fine nozzle, as it allows for a controlled and gentle flow of water, ensuring the soil gets wet evenly without causing soil erosion. Rainwater is best for watering, but tap water can also be used if rainwater is unavailable.

Spray Bottle

Using a spray bottle is essential for maintaining the humidity around your bonsai tree. Regularly misting the foliage helps to replicate the tree’s natural environment, keeping the leaves hydrated and healthy. Make sure to use a clean spray bottle and fresh water to avoid the spread of bacteria or other contaminates.


Utilizing a tray beneath your bonsai tree is crucial to guarantee proper drainage and humidity control. Place the tree in a tray filled with pebbles or rocks, adding water up to 1/3rd the depth of the soil in the bonsai pot. This setup allows excess water to drain while maintaining moisture for the tree’s roots.

Watering Frequency and Timing

Watering a bonsai tree indoors requires a balance between providing enough moisture for the tree’s growth and preventing root rot caused by excess water. The ideal watering frequency for most bonsai species ranges from once per day to three times per week, depending on factors such as the tree species, pot size, and climate conditions (Self Gardener).

Beginner-friendly bonsai trees, such as elms and ficus, can tolerate less frequent watering while still achieving effective growth. Indoor bonsai trees typically should be watered once per day (The Bonsai Master). Keep in mind that the watering needs may change depending on the season, the tree’s size, and the type of soil used.

When watering an indoor bonsai tree, use a gentle shower to moisten the soil without disturbing it. Room temperature water is preferred, as cold water may shock the tree and hot water may contain harmful chemicals like chlorine. A good practice when watering is to fully submerge the bonsai pot in a water-filled container, ensuring the water reaches the rim of the pot, and allow it to sit for up to 30 minutes (Bonsai Starter). This technique ensures that the roots absorb the necessary moisture for healthy growth.

Step by Step Watering Process

Checking Soil Moisture

Before watering your indoor bonsai tree, it is crucial to check the soil moisture. Do not rely on a strict schedule; instead, evaluate the moisture by feeling the soil with your fingers. If the soil feels slightly dry, it’s time to water your bonsai tree. Keep in mind that the watering frequency may vary depending on the tree species and environmental factors.

Watering Method

Thoroughly soaking the entire root system is key to a healthy bonsai tree. One effective method for indoor trees is the bottom watering technique, where you place the bonsai pot in a water-filled container, ensuring the water reaches the pot’s rim. Let the pot sit for up to 30 minutes, allowing the soil to absorb enough water

Misting and Humidity

Besides providing water to the roots, it is essential to maintain adequate humidity around your indoor bonsai tree. Misting the foliage on a regular basis helps to maintain the moisture levels required for the tree’s optimum health. Additionally, using a humidity tray can contribute to providing your bonsai with a more suitable environment.

Signs of Over-Watering and Under-Watering

Identifying the symptoms of over-watering and under-watering is crucial in maintaining the overall health of indoor bonsai trees. Over-watered bonsai trees often display symptoms such as yellowing leaves, root rot, and mold growth, while under-watered bonsai trees might exhibit leaves changing color, becoming brittle, or falling off out of season (source).

To address over-watering, it’s essential to let the soil dry out and adjust your watering routine. To help revive an over-watered bonsai, remove the tree from its pot, and use a hairdryer to dry the roots carefully, keeping the heat at a safe distance of about 10cm (source).

For under-watered bonsai trees, start by increasing the watering frequency and consistency. The ideal watering method may vary depending on the size and type of the bonsai tree, with options including top watering, bottom watering, and using the kitchen sink method (source). It is also beneficial to mist the foliage every couple of days to keep it hydrated, especially for juniper bonsai trees (source).

Bonsai Species and Watering Requirements

Different bonsai species have varying watering requirements. Understanding the specific needs of your indoor bonsai tree is critical to ensure proper care and growth.

While there is no one-size-fits-all watering schedule, a good rule of thumb is to water your bonsai tree when the soil starts to feel dry. This can range from every four to seven days for many species, but it’s essential to be attentive and adjust the frequency as needed for your specific tree (Bonsai Guide).

When watering, thoroughly saturate the soil. For indoor bonsai trees, you can place the tree in your kitchen sink, allowing excess water to drain out before returning it to its original location (Bonsai Empire). Rainwater is ideal for watering your bonsai since it lacks added chemicals. However, tap water is generally a suitable alternative.

To maintain an optimal environment for your indoor bonsai, consider placing it on a humidity tray filled with water and periodically mist the tree during the day (Bonsai Empire). This can help increase humidity levels and prevent the soil from drying out too quickly.

Common Mistakes to Avoid

One common mistake when watering indoor bonsai trees is using an incorrect watering technique. Instead of drenching the soil, it’s better to use a watering can with tiny holes in the nozzle or a watering hose, which resembles rainfall and provides a gentle stream of water to the soil and roots (source).

Another mistake to avoid is overwatering or underwatering your bonsai tree. It’s crucial to be mindful of the amount of water given to your bonsai trees, as too much water can drown them, while too little can lead to dehydration (source). Gauge the need for water by using a moisture meter, your finger, or the chopstick method instead of relying on a routine (source).

Lastly, be aware of the light requirement for indoor bonsai trees. Insufficient light can weaken the plant over time and result in reduced growth (source). Ensure that your tree is placed in a bright location with enough exposure to light.

Additional Tips for Indoor Bonsai Care

It’s essential to maintain proper humidity levels for your indoor bonsai tree. One technique is to place your tree on a humidity tray filled with water and misting it a few times daily. Also, ensure regular air circulation by opening a window during the day.

Monitor the soil moisture before watering your bonsai, by checking about one centimeter deep (0.4″) with your finger. Water your tree when the soil is slightly dry, but don’t let it dry out completely. Over time and with experience, you’ll know when to water your tree more effectively. Avoid watering on a strict routine.

When repotting your indoor bonsai, use a combination of soil types to ensure proper nutrients and drainage. Add a layer of Akadama, followed by a layer of Boon Mix, and then top it off with a layer of Kanuma. Including organic material in the soil mixture will also help with aeration and drainage.

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