I just came back from vacation and noticed something is wrong with my peonies. I'm a peony novice so forgive me if this is an all-too-common question; I did read through the forum a little already. They are all dusty looking. There are some black spots, but overall a few black marks on the leaves doesn't seem all that out of the ordinary. The stems aren't black and the plant doesn't look like it is rotting or anything. Just very, very thoroughly dusted-over. I also saw two leaves that seemed to have a pile of what looked like white granules on it. Not sure what that was.

So I'm thinking it is due to the wet weather (though since I was away I'm not 100% what the weather conditions have been) - a mold, mildew or fungus and hopefully not a pest infestation. The question is what do you all think it is and how to best treat it?

I'm contemplating whether I should just be cutting them back to be safe. I know I might risk losing next year's blooms but I'd be willing to sacrifice them to save the plants. Prior to this they have been healthy, full, and plants with lots of beautiful blooms and no real problems. I've seen reference to a Bordeaux formula but am not sure waht that is and generally prefer not treating with chemicals if it can be avoided (not a big deal but prefer not working with them or having them around if it can be helped).

I would be grateful for any tips or similar experiences. Thanks so much!