Quote Originally Posted by grandpa
Does anyone know what causes powder mildew?
Airborn spores are everywhere and will begin to grow where ever conditions are right for them.
Warm, humid, stagnant air will kickstart it, and a plant's overall health can limit, or augment it's growth.
The best defense is a lush, vigorous, plant with good ventilation.
For remedies, just do a local search.
Can't help you with that, because the only real remedy here in the jungle, is to grow resistant strains.

Good luck with it.
Wee Zard