Potassium bicarbonate for mildews
Well, in years past, I've tried baking soda, neem oil, milk, and vinegar for powdery mildew. Then I found out that plants need to be treated PRIOR to exhibiting symptoms. I had read that potassium bicarbonate was better than baking soda, but had never tried it.
This year, I was going to get a jump on it, but the humidity and heat came about 2 months early... Voila! Powdery mildew.
Recently, I read that potassium bicarbonate could not only control PM, but could actually cure it some -- even after symptoms.
So I went and found some at a wine making shop. I clipped the most affected leaves off my cucurbits and gave all of them a good spraying.
I plan on going with a 1 week schedule for a few weeks and then a 2 week if there's no further damage.
I'll let you all know how it goes later this summer.