Let us know how this worked out long-term. I never heard of it, but there seem to be a lot of remedies.

When I got back into AVs a few years ago, I immediately got powdery mildew on a shipment from a grower. Maybe it was an especially nasty strain but the home remedies didn't work. I know I tried the Lysol. I didn't find a cure until someone recommended a product called Fung-away, which I've read has been discontinued.

I tried milk with no luck, but I think one time I caught just a little bit on a leaf and washed it off with soap. Maybe if you get it early, many things may work. I often have problems with new leaves or plants and just treated one plant for the third time. I mixed fresh spray so I hope that takes care of it.

Hmm, I guess alcohol doesn't mar coleus when you treat mealy bugs, but I've seen warnings about succulents. (I just found some on a jade - hopefully it didn't spread.)

Good luck with that stuff. It must not have been much of an issue for years for me. Do let us know if it comes back.

Diana in PA

Here's an older message that deals with this

http://forums.gardenweb.com/forums/load/afrviolet/msg060737519872.html

I decided to look up powdery mildew and it says it's plant specific although there are different kinds. It mentioned the baking soda and I wondered about that one.

It also said to discard affected parts (I think they were referring to other types of plants) and I have sometimes found it one one leaf and simply removed it. This is chancy but may work if you caught it in time. (The soap and leaf removal are when I'm tired or lazy, almost like crossing my fingers and hoping it goes away.)

Diana in PA