How to avoid and deal with white fuzz aka powdery mildew?
White fuzz means your plant is under a fungus attack. Make sure your plant gets enough sunlight, space and air circulation to avoid further damage.
You can also apply fungicides to prevent white fuzz (powdery mildew). Please consult a tree expert or your local nursery to help you choose the right fungicide.
If your plant is already affected by white fuzz, you can apply specific plant based (horticultural) oil sprays which can heal your plant. Again, please consult before choosing the oil.