Care Of Bonsai Trees: Fungi – Three Things To Look Out For
bonsai trees
Despite our best efforts with our care of bonsai trees, our trees can get diseases and we need to be able to identify them and know how to combat such fungal infections such as mildew, rusts and black spot.
Mildew is a white mould forming on the foliage. It extracts the sap from the tree. It then spores over winter and emerges with the buds and foliage in the spring.
Rusts are another fungal disease that causes raised brown and or orange areas on the underside of leaves. This is especially found in Beech or Birch species.
Black Spot is a cluster of black spots on the surface of the leaves which results in the foliage turning yellow and then dropping off. This type of fungi is commonly found on Chinese Elms.
You need to be aware with your care of bonsai trees, that there are three main ways to treat fungi so it is best to think about what you are trying to achieve and match that up with the appropriate type of fungicide before you treat your tree.
1. PROTECTANT is a fungicide that will shield healthy tissue from invasion.
2. ERADICANT will kill fungi that have already invaded the plant.
3. SYSTEMIC fungicide spreads within the plant and can protect areas that have not been directly affected by the fungi.
The following is a list of chemicals that appear to work best on fungal infections:
Mildew: Triadimefon
Rust: Chlorothalonil, Mancozeb, Propiconazole
Black Spot: as per the others above and Benomyl
When trying out fungal treatment, it is best that you do not treat the entire area until you gauge how that particular fungicide affects your tree. Just start by treating a small piece of the tree and see how it responds before going over the whole plant.
Fungus is spread via water and thrives in warm wet conditions. Before you water your tree, check to see if there is any fungus. If you see that there is, it is best that you do not spray too much water onto the foliage as the water helps the spores to travel. Also consider that during long periods of warm rainy weather it is best to shelter your tree from the rain for a while so to give it a spell from those warm, wet conditions.
As is always the case, prevention is better than the cure and this holds true with the care of bonsai trees. You can assist your tree to ward off infections by keeping your tree healthy and seeing that it is fed and watered adequately, given plenty of fresh air and sunshine, kept dust and debris free and not placed under any unnecessary stress.
In addition to all your regular care of bonsai trees, stay on the lookout for fungi and get rid of them quickly so that your tree will continue to thrive in good health.
If you would like to find out more on the best way to take care of bonsai trees bonsai trees care