I stopped mulching my peonies several years ago (after I got a CLUE!) and I've had tremendous blooms ever since.

I'm confused. It's ok to mulch them in the summer growing season but don't mulch them in the winter? Is that what your saying?

I think you have to consider why you are mulching. I have grown peopnies for many years in zone 3 (with no mulch)and they certainly are hardy enough to withstand our winters. However I have moved to a new location with very light sandy soil and have access to free wood chips so have begun to mulch everything. the mulch really helps to hold the moisture as well as improving my soil . I am careful not to mulch too heavily around the emerging crowns. I also like to apply compost each year. The other thing to remember is that peonies should not be planted too deeply or they will not bloom. the top of the crowns should be between 1-2" just below the surface of the soil, no deeper! Growing peopnies in a zone 7, it would make sense to mulch in the summer for moisture but not in the winter as they need the cold exposure.

I am in a warm winter area and do not mulch. I do compost AROUND the peonies but not ON them. Peonies love rich soil with lots of vegetative matter. When I cut them back in the winter I hose any accumulated soil from the top of the roots to assure good winter chilling. Al

When my peonies were dormant one year I covered their entire area with about 2 inches of coffee grounds. I thought this would keep the cats from pooping there. (Helped a little.) Over the winter the grounds melted away and I had great blooms the next year.

I mulch Tree Peonies.