7 Reasons Why Bonsai Leaves Turn Yellow

Bonsai means planted in a container, and this is to grow a miniature version of a complete tree. Any tree can make a Bonsai. These are not dwarfed trees but are explicitly created by pruning and wiring branches that limit their growth. These are normal trees which are just trimmed naturally to remain small.

How to grow a Bonsai tree

You first must figure out what tree species matches your needs and desires, the climate and circumstance. One thing that will affect your selection is whether you prefer to keep your tree indoors or outdoors, and growing Bonsai tree outside gives you more options to choose from.

When you grow Bonsai trees indoors, it will limit your subtropical tree options. The non-tropical trees are best suited to grow outside as long it is protected from intense sunlight and freezing temperatures. When you have identified the type of tree you want to grow, there are different cultivation methods. The best choice is to buy a Bonsai tree online, which is ready-made. They come in various shapes and sizes but at a very high price, especially the old ones. Then the most economical way to go about it is to buy the pre-Bonsai stock, and you will achieve great results. Or you can collect from your surroundings very cheap. You can decide to do it as a side project by actually growing your tree which will take from 3 to 5 years to develop and style.

Styling and Shaping Techniques.

It is the most challenging part though it can take years to master the techniques like pruning. The goal is to create the Bonsai that replicates the miniature version of a full-grown tree in its natural environment. The best season to prune your Bonsai trees is spring, though this depends on your tree type. Buy a pair of concave cutters when you are pruning a thick branch. These concave cutters make a good hollow wound that heals faster and much better than those made by standard blades.

You can also use wiring as another technique to shape your Bonsai tree. It can be done by wrapping anodized aluminium carefully or annealed copper wrapped around the branches; you can shape them to your satisfaction. One thing you should not forget is to remove the wire before it starts to dig into the branches that grow thicker.

Care and Maintenance

It is the most crucial part of growing a Bonsai tree. Every tree species has got its specific care and maintenance guidelines.

1. Watering your tree

Watering a Bonsai tree depends on many factors such as the tree species, soil components, climate and pot size. Bonsai are usually planted in small pots, which tend to dry up quickly; this makes it essential to water your Bonsai regularly. Over watering can cause root rot which is among the leading causes of death to most Bonsai.

2. Soil mixture

Another crucial part of your Bonsai tree is choosing the right amount of soil mixture; repotting is vital. Ensure you water your Bonsai regularly, and the soil absorbs water properly. Before purchasing, you should decide whether to place your Bonsai tree outside or inside.

3. Fertilization

It is another essential factor always to remember. You must fertilize regularly during the tree season to enable the tree to grow and become healthy. The amount of fertilizer to put will also depend on the type of species you have. You have to apply little fertilizer than a regular tree requires, and liquid or solid fertilizer will not harm your plant.

What it means when your Bonsai is turning yellow

A Bonsai leaf turns yellow when deciduous, which happens to any regular tree during autumn. Most cases of the yellow leaves indicate there is a problem. There are many reasons why your Bonsai is turning yellow, but fortunately, not all of them are causes for alarm. It can relate to cold air, stress, trimming and overwatering.

Factors that could cause the leaves of a Bonsai tree to turn yellow

1. Overwatering or Underwatering

It is the most common reason for the leaves turning yellow. Bonsai trees require their roots to be soaked but not stagnant to thrive. Ensure you regularly check your Bonsai soil to see if it receives enough water.

You can stick your finger inside the soil; if it is dry, you need to water the plant. Underwatering leaves your Bonsai with brown leaves.

How to correctly water your Bonsai tree

The correct way of watering the Bosai is first to pour water on the top layer to ensure that the soil has been saturated evenly for the water to be absorbed by the roots, then pour the water into the whole pot and allow it to soak before pouring more. Check your Bonsai daily for moisture because many Bonsai trees need multiple waterings daily.

It is determined by the time of year and the environment. Use soil designed explicitly for Bonsai trees, then place the tree inside a pot with drain holes, ensuring proper drainage. When the roots stay in stagnant water, they rot and attract parasites.

2. Sunlight

Lack of sunlight is among the biggest reason for the Bonsai leaves to turn yellow. Bonsai needs a lot of the sun, just like any other tree, but some species require a small amount of sunlight. The chlorophyll in the leaves makes the plant green, which is produced by sunlight.

Amount of sunlight required by a Bonsai tree

A Bonsai tree requires a minimum of 5 hours of direct or indirect sunlight each day. The best thing to know about the species you are growing is that some of the species require indirect sunlight while another requires direct sunlight. Here is one thing: A Bonsai tree with inadequate sunlight will struggle to survive.

3. Hard trimming

When you trim your Bonsai trim excessively, it will make the leaves turn yellow. You are not supposed to trim your Bonsai tree if you see it is not healthy. It would be best if you did not trim your tree when you have repotted or transplanted it. It would help if you gave your Bonsai tree time to adapt to its new environment. You should water the plant and allow it to get enough sunlight before you start trimming it. Ensure you clean your scissors when you are done trimming one plant before you go to the next to avoid spreading diseases from one plant to another.

4. Imbalance of mineral salts

These Bonsai trees require to be fertilized during the growing season. It is likely to have too much of one mineral or nutrient in the soil. When potassium levels are high, calcium will be deficient. You can check this using a soil testing kit available in gardening stores.

How to often fertilize a Bonsai tree to prevent it from turning

It is best to fertilize your Bonsai tree every 7 to 10 days during the growing season. It means once every month during a dormant season. Ensure you use a fertilizer that is specifically for Bonsai trees.

5. Stressing

The different types of soil, temperature, level of light, or a new kind of water can cause significant stress on a plant. When you have changed how you care for the plant, it might cause some yellowing only for it to adjust.

6. Disease

Some Bonsai tree species are prone to diseases which turn their leaves yellow. When you want to know what condition your Bonsai tree is suffering from, find out the type of disease that usually affects your Bonsai species.

7. Pests

When pests attack your plant, you will notice brown spots on the leaves. Different species of Bonsai have other problems that attack them, and you will need to know and understand what pests attack your Bonsai tree. In warm and dry weather, spider mites are the common pests though they are not the only pests that leave a brown mark on the leaves.

How to care for your Bonsai tree if it’s turning yellow

1. Increase Drainage or Decrease watering

Did you know that overwatering is more risky than underwatering? Overwatering can highly result in the death of your tree. You can confirm this by looking if the leaves are yellow but still plump, which indicates an overwatered plant. You will want to ensure that the water is not collecting around the tree roots. To avoid water collection, you should provide better and more efficient drainage, or you can minimize the amount of water you give the tree.

2. Reduce Pruning

When your Bonsai tree is stressed, it is better to avoid pruning for some time. Shaping, cutting and styling are essential parts of Bonsais maintenance, and overdoing it can stress your tree. You can leave the leaves to grow a bit to monitor whether the leaves will grow if they are green and healthy.

3. Increase Watering

You very well know you should avoid overwatering and make sure you ensure that the tree is dry so that you can increase its water intake. If your tree has wilted and yellow leaves, you should add a little more water to the tree.

4. Move Your Tree

Your plant might be turning yellow because of too much or very little sunlight. When you notice your tree losing leaves on one side, that will show you the part that gets little light, and over yellowing will show that it requires sunlight as a whole. You can as well consider moving your tree outside as it is known that many plants thrive well outdoors.

5. Give the Tree more Nitrogen

It is a vital component for healthy growth and green leaves, and this is because it is a central component of chlorophyll. A small amount of Nitrogen causes the leaves to turn yellow; therefore, a nitrogen-rich fertilizer will do the magic and reduce the yellowness of the Bonsai tree. What you should not do is overload your tree and always select the best fertilizers for the type of species you have.

How to Prevent Yellow on Your Bonsai Tree

If your Bonsai tree has not turned yellow, then there are measures you can take to avoid it, leaving your tree looking green and healthy.

1. Water with Care

It is the most lifelong battle for the plant owners, knowing the right balance when watering them. Ensure that your tree’s soil can drain quickly by having a well-drained pot. Avoid saturation, and do not allow your soil to be arid.

2. Choose Healthy Soil

Most of the time, the type of soil you choose for your Bonsai can be out of your control. What you can do is ensure there is the right balance of minerals in your soil.

3. Always Choose an Evergreen Bonsai Tree

Choose an evergreen tree simply because some trees will lose some of their leaves seasonally, and it will not matter what you do. To avoid this purchase, look for an evergreen bonsai tree that has its green colour all year.

4. Avoid Stress

Always limit the amount of stress your plant experiences. It would help if you did not change how you care for them, or sometimes drastic changes in their environment can cause pressure on the Bonsai tree. Do not over-prune or make unnecessary adjustments to your plant.

5. Locate Your Plant Carefully

Choosing a good place to place your Bonsai tree can be challenging and affect their growth, which can be very easy if you put it correctly the first time. Ensure they get a good amount of sunlight throughout the season.

Do not focus on one side of the tree but on all of the parts of the tree.


Bonsai trees turn yellow sometimes, just like other trees. Mostly this can be natural seasonal shedding or some changes that are occurring to your tree. The leading causes for the Bonsai leave turning yellow are overwatering, underwatering, change in the level of sunlight and mineral deficiency.

Taking care of your Bonsai tree is not that challenging as long as you use their unique tools and techniques to care for them. Do not over prune, and always ensure you check the water level and the amount of intake your Bonsai tree takes.