The affected plants have been trimmed. I'll spray them later today with a fungicide to hopefully prevent the spread of any disease to other plants.
Chelle, I do trim the peonies, and clean up the garden beds in the fall. The weather has been so damp and cool here this spring, which is not helping this problem.
I'll be keeping a close eye on my other plants, only one of my Sorbet, Bernice Carr, and a white noid were affected.