Caring for a bonsai tree can be a lot of fun, and it can also be a relaxing and rewarding experience. However, part of this journey involves encountering many different challenges. Aside from the fact that maintenance can be a lot of work, an infection, disease, or mould problem might also come your way.

Mould and mildew are serious problems that can harm your bonsai trees. If you can spot these issues and identify them right away, you will be able to find ways to keep your plants healthy and thriving. 

In this article, you’ll get those answers you seek, especially in getting rid of mould growing on a bonsai tree.


What Does Mould on Bonsai Mean?

Mould refers to fungal diseases that can affect your bonsai tree. These issues start at the bonsai’s foliage, while others begin at the branches or the roots. Most of the time, mould comes from too much exposure to wet or humid conditions. In worse cases, the mould can overwhelm the bonsai tree, which will be left helpless against the infestation. 


What Are the Common Types of Mould That Affect Bonsai?

There are two main types of mould that can harm your bonsai tree: pathogenic and non-pathogenic.

Pathogenic mould refers to those that you can find within a poor soil mixture, and they are not the kind that will aid the composition of the soil, unlike Pythium or Phytophthora. With pathogenic mould, the bonsai trees are affected because the nutrients can’t pass through the roots to get to the stems.

Unfortunately, it can be hard to identify pathogenic mould until the damage rises to the upper part of the plant.


How Do You Identify Mould in Your Bonsai Plant?

Do you want to know if your bonsai tree is in trouble? Here are some signs you should look out for.

  • Leaves showing up with red, orange, or brown spots
  • Leaves having fine, hair-like filaments sticking out
  • Flowers and leaves appearing discoloured or distorted
  • The plant slowing down growth or ceasing to grow altogether
  • Drooping or wilting branches
  • Shoots dying starting from their tips


What Can You Do to Treat Mould on Your Bonsai?

Once you identify these signs on your bonsai tree, you need to start treatment right away. But before you begin, it’s important to note that you should prevent the mould from spreading to other parts of the plant and neighbouring plants in your garden.

If your plant gets infected with mould, you should follow these tips:

  • Sterilise your gardening tools before you prune your bonsai tree.
  • Remove the parts of your plant that are infected.
  • If you have other plants in your garden, isolate the bonsai plant from them.
  • Buy fungicide and spray it on your plant.
  • Place your plant in a dry area to prevent moisture from building up and encourage further mould growth.
  • Increase the air movement around your bonsai trees.
  • Make sure you identify the root cause of the problem so that you can correct it.



If you keep your bonsai tree well-cared for, you can keep it healthy and free from moulds. However, even the best gardener and bonsai carer may experience mould threats at some point. If you are educated on the proper steps to take, you can get rid of the problem right away.

Are you ready to start building your bonsai garden? Buy bonsai plants online through Bonsai Shop. We offer bonsai starter kits, pots, accessories, tools, and bonsai trees for enthusiasts all around Australia. Shop our collection today and get started!