Mold and fungi on trees: effective biological methods for prevention and control

The health of a tree can be significantly affected by mold on the tree trunk and tree bark. Especially in summers with a lot of rain, the combination of long-lasting moisture and a lack of ventilation can encourage the development of mold. Here we present some non-chemical and biological methods for combating and preventing mold.

1. Regularly ventilate and check the tree grate 

Removing tree bags at regular intervals:
It is very important to remove the watering bag at regular intervals, especially after a long period of rain. This allows the tree and the tree ring to dry out, preventing the formation of mold.

Ensure ventilation:
If you use layers of mulch, these should be loosened regularly and reduced if necessary to ensure good air circulation around the tree trunk and tree disk.

2. Promote tree health

mulching:
Moisture regulation and mold formation can be achieved by a thin layer of organic mulch (e.g. bark mulch). To prevent waterlogging and mold formation on the bark, the mulch should not be placed directly on the trunk.

Water properly:
Correct watering is crucial. It is important to ensure that the soil drains well and that there is no waterlogging. Watering should be done when necessary and the bag should only be used when needed.

3. Remove mold yourself 

Careful brushing:
With a soft brush it is possible to remove light mould on the bark. It is important not to damage the bark. The tree must then be well ventilated so that mould does not reappear or the existing mould does not spread.

4. Natural means of combating mould 

Vinegar solution:
To remove mold, a small amount of vinegar solution can be applied to the affected areas. Vinegar has fungicidal properties while being gentle on the tree. Ordinary apple cider vinegar is sufficient.

Baking soda solution:
A combination of baking soda and water can also help fight mold on tree bark. Baking soda causes a change in the pH level on the surface, making it harder for the mold to grow. To do this, mix a baking soda packet with a liter of water and spray the affected areas.

5. Support from helpful microorganisms 

Compost tea:
By using compost tea on the tree disk, helpful microorganisms can be promoted that can naturally act against mold and other harmful fungi. These microorganisms compete with the mold and have the ability to push it back naturally.

6. Preventive measures 

Checking the tree location:
If possible, the tree location should be chosen to ensure good sunlight and air circulation. Shade and damp areas encourage the growth of mold.

Adaptation of tree care measures:
The use of watering bags during the wet and humid winter seasons is not absolutely necessary. Therefore, the bags should be removed or stored in a dry place so that the bark is well ventilated and dried. In general, the bag should be removed from time to time and not left on the tree trunk for months at a time. This measure is particularly important in summers with a lot of rainfall.

If, despite these biological and natural methods, the mold continues to be a problem and begins to damage the tree, chemical methods should be considered to save the tree. To make the use of chemicals as targeted and environmentally friendly as possible, we recommend that you seek advice from a tree expert.