It doesn't really look like downy mildew. Are you close to salt water? It almost looks like salt spray.

Powdery mildew. Far different than downy mildew!

DUH!!! Believe it or not, I MEANT Powdery Mildew. LOL ;)

hey - for powdery mildew you can spray your plants with a mixture of 1 part skim milk and 9 parts water. You can do a google search "mildew milk" and see if you can find results of research there. I have been using this mix for several years and it took care of the problem for me on my phlox and roses - I don't know why it wouldn't work on hibiscus too. I would spray it on in the spring - about every third day for a couple of weeks and then once a month if you want. The milk sure seems to strengthen them to fight off the fungi!

Good luck
Kiwi in Kalamazoo

Hi All:

Thanks for the info. I hope I can clean the problem up before winter strikes and freezes the poor thing.;-)

Cheers,
MG