Spray with neem oil. I use Montery Brand.
http://www.planetnatural.com/p...
Spray all the leaves, top and bottom and along the stems also. Make sure you spray both healthy and sick leaves.
Spray toward evening when the bees are gone and do not spray if it is too hot. (over 90) That is why I spray in the evening.
Neem will control the mildew but you need to keep spraying. I would spray again three days later and then spray weekly. It should control the mildew. I have to spray all my summer squash and the Neem does work well.
