Greetings from Lewiston, ID. We all live in the same part of the world perhaps we share something as regards powdery mildew. I noticed that bindweed seems to be a favored host for powdery mildew. In fact, everywhere I have bindweed I have pm and none of the areas without bindweed have any pm. Are you guys seeing anything like that? The pm starts out on the bindweed and spreads to the plants the bindweed touches. I've found that by just pulling the bindweed I solve the problem (as long as I'm using good cultural practices such as watering early, etc.). Liz