This post is from Ward Upham, originally on the K-State Horticulture Newsletter
Peonies often look a little bedraggled by this time of year and gardeners may want to cut them back. That will not be a problem with this perennial. Peonies are essentially dormant by this time of the year, even though leaves may still be green. Cut leaves off close to the ground and compost or discard. (Ward Upham)
