Leslie, I put my original 6 peonies in, in about 1990. For many, many years we had not one trace of mildew on them. But then one year about 10 or 15 years, we had a particularly rainy spring and summer. One day I went out and discovered that someone had sprayed white paint all over the peonies. We lost one of the 6 of them, because it was so bad for a couple years. Finally, I discovered the Cornell spray recipe. It prevents mildew as long as I can remember to spray them every couple weeks during the growing season. The problem is that I get tired of doing it after they bloom, and then the mildew sets in. Last summer it got bad. It weakens them, so this spring they didn't put on as much of a show as they are capable of doing.
