My gerberas seem to have powdery mildew.?

I have several, some in pots, others in the ground. The ones in the ground are watered by sprinklers and the potted ones are hand watered at the base. Yet, one by one, the leaves are becoming covered with a white powdery substance. They are well fed and are spread out over the yard.

Advice, please?
My gerberas seem to have powdery mildew.?
Fungus. There are a lot of treatments on the market for this. The water splashes the spores around thus spreading it. The wind will do the same.
Reply:Try dish soap and spray on.
Reply:Not much you can really do about it and it doesn't hurt your plants. It's because of humidity and cool nights. Don't overhead water...that's the best advice. Again, there's nothing you can really do about it. Fungicides won't do a damned thing.