White powdery substance on zuchinni and butternut squash

by Michael Tithof
(Fowlerville, MI USA)

I have never had a problem growing vegetables until now.
There is a white powdery substance that now shows on my zuchinni and butternut squash plant leaves. What is it and how do I get rid of it?

Doug says welcome to powdery mildew. Here's a control article right here. And yes, I know it says that the page is about roses but the disease is the same. :-)