Bonsai Tree Diseases

Bonsai tree diseases can be detrimental to your plants, and if not attended to, they may spread and eventually kill your tree. By recognizing the symptoms, you can stop the spread of these diseases and save your plant.

Bonsai Tree Diseases

Issues Associated with Bonsai Trees

Taking care of a Bonsai tree means more than just watering and giving it lightly. It needs a certain amount of light, heat, water, and fertilizers. If a bonsai tree is under a lot of light or not receiving enough light, then the leaves will discolor and wilt. Overwatering your bonsai leads to moist roots,s which will eventually rot and lead to infections.

There are certain types of fertilizers and using a lot of organic fertilizers or soil could be detrimental for your tree. Another issue with Bonsai trees is pruning. It needs to be done correctly and wound paste application afterward.

Another main problem is pests, which are and deliver infections and viruses to trees. There are different types of pests that you may come across depending on the kind of environment and temperatures surrounding your tree.

These include Vine weevils, spider mites, aphids, mealy bugs, scale insects, caterpillars, and ants. The best way to prevent your plant from pests is regularly checking your plant and applying pesticides.

We have a detailed bonsai tree care guide with all the relevant information. Check the guide out here!

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How Do You Know When Your Tree is Ill?

Sometimes trees can contract diseases from fungi or pests; therefore, it is crucial to recognize the symptoms of the diseases. The most common symptom is the discoloration of foliage to yellowish color and eventually fall off, branches may be is weakened branches and irregular growth of the tree.

Common Bonsai Tree Diseases

Now that you have a better understanding of how your precious plant baby can become infected, let’s take a look at the more common bonsai tree diseases.

Black spots

Bonsai Tree Diseases

This disease affects the leaves and appears as black spots around the foliage. As it spreads further, the leaves will turn yellow and be shriveled, and eventually drop. Once the leaf is affected, it should be removed, and the healthy leaves sprayed with fungicide. Watering the plants encourages the spread of the diseases, and thereof you should wait until the spread has vanished to water your plant again.


Bonsai Tree Diseases

It’s crucial to ensure that your tree receives proper sunlight and enough aeration before mildew or mold results. You’ll notice this by a white or black powdery substance developing on the leaves, stems, and branches. This can hinder the plant’s growth, cause discolouration, and even damage the health of the tree as a whole.

To cure the plant, you need to thoroughly remove the affected parts of the tree with a fungicide to prevent reinfection. In cases where mold is caused by insects, remove the insects either by hand and/or spraying insecticide. The affected leaves still need to be removed.


Bonsai Tree Diseases

Rust is a fungal disease that appears on the undersides of the foliage as yellow, red, brown, or orange bumps, which eventually leads to leaves curling up and falling off. Although it’s not fatal, it can still cause severe hard to your tree, which is why it is essential to immediately remove the affected areas and apply fungicide to prevent reinfection. Your tree needs enough light and ventilation to avoid this disease.


Bonsai Tree Diseases

This disease is a result of the lack of chlorophyll in the plant. It damages the root system leaving it compacted and leads to a lack of nutrients like iron. Foliage will turn yellow while the veins remain green until the tree starts to wilt. To treat this, you need to add chelated iron to the water and regularly take care of your root system.

Root Rot

Bonsai Tree Diseases

Not draining your tree correctly could lead to the roots of your tree rotting and turn brown and stale. This leads to discoloration of leaved and weakened stems, and thereof growth will be hindered. In this case, you need to prune away all the affected root systems and replant the tree in fresh soil. Make sure that the soil and container you use allows for water to pass through.

Scab or canker diseases

Bonsai Tree Diseases

Scabs are types of diseases that appear as though the leaf is fading color, poor growth of the tree, and often the bark swells up. It can be caused by various conditions like poor pruning, excess nitrogen, and sometimes improper fertilization. To treat this, you have to cut out the infected area and apply wound paste around it. It’s vital to ensure that you follow the correct pruning and fertilizing procedure to prevent this from occurring again.

How to Protect your Tree from Illness

Bonsai trees need the proper conditions to thrive, and if ever those are not met, you’ll start to notice some leaves falling and some certain shades developing. If these aren’t prevented, then your tree will eventually die. By keeping your plant clean and getting rid of the waste material that has fallen around the soil, you can prevent your plant from many diseases.

Furthermore, you can save your plant by using less-compacted soil to allow for aeration and water to pass through. You need to re-pot so that your tree is not pot-bond. It’s essential to prune appropriately with appropriate pruning techniques that are safe for your tree and applying wound paste afterward for quick healing. In addition, the application of fungicides goes a long way, even after you have removed the infected leaves or branches.

Bonsai Tree Diseases

Final Thoughts

It is vital to make sure that your bonsai tree is under the right conditions; otherwise, it will be in danger of contracting infections or pests. Once you can recognize symptoms, you will know how to react in terms of saving your tree. Some pests, like the red spiders, are difficult to notice with the naked eye, but pesticides work either way.

Diseases can be carried from one tree to another through pests, so be cautious and separate the infected tree from the others until it has been cured. The most important thing is to remove any infected area immediately before the infection spreads. With a touch of fungicides, pesticides, and wound paste, your tree should heal and continue to grow normally.

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Priyanka loves writing about all things bonsai, from the history of the art form to how to properly care for your plant. She also enjoys writing about other plants and gardening in general. She’s done a lot of research on bonsai trees and their history, and it opened her eyes to the world of miniature gardening.

Bonsais are so small and delicate, but they’re so full of life. Her passion for Bonsais is what got her attracted to miniature gardening. She has converted a corner of her living space into the prettiest Bonsai garden. She loves that Bonsais make her feel like there’s more to this world than just what we see around us every day.

Olwethu Msesiwe



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Bonsai Tree Diseases

Bonsai Tree Diseases Bonsai tree diseases can be detrimental to your plants, and if not attended to, they may spread and eventually kill your tree.

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