Like any other living plant, Bonsai trees can be infected by any kind of pest or disease. However, when your plants are healthy and cared for properly, the risk of infection is reduced to a minimum.

Make sure your trees are potted using the right soil mixture, you understand how and how often to water, you don’t over or under fertilize and your Bonsai is placed right. Although chances of infection of healthy trees are low, of course they can still get infected. As it is often hard to identify the problem correctly you might want to take pictures and ask for help at our Bonsai forum.

Identifying Bonsai pests and diseases

These are some of the most common problems people experience with their Bonsai trees:


Dying leaves on Bonsai

Leaves suddenly turn yellow and fall of the tree. This is often the result of a sudden lack of water. When the leaves slowly turn yellow and die it is most often the result of sustained overwatering, overfeeding or underfeeding


Insects often found on Bonsai

Try to identify the insects either by photographing them and asking for advice at on online Bonsai forum, or by comparing the insects you see with the pictures below.



Aphids on a bonsai tree




Spider mites

Spider mites on a Bonsai tree


Mealy bugs

Mealy bugs on a Bonsai tree


Vine weevils

Vine weevils on a Bonsai tree


Scale insects

Scales on a Bonsai tree



Caterpillar on a Bonsai tree



Ants on a Bonsai tree


After you have identified the insect buy an insecticide (chemically or organically) to treat the trees with; be careful to follow the instructions and you might want to start using a half doses first, if necessary you can increase the doses later on.



Viruses and Fungi

Viruses can be detected by discolored leaves and sudden dieback of branches. Place the infected tree separately from your other trees to prevent cross-contamination. Treat by removing infected parts from the tree and by applying a fungicide spray.