|How long should I wait after peonies fade to cut them back? It has been a month already. How often should they be divided?|
|Peonies do not require pruning per se. You may remove the flowers as soon as they fade, but leave as much foliage as possible to help the plant rebuild its strength to bloom again next year. In the fall, after frost has browned the tops completely, trim them off at the base. Mulch the base of the plant with a 2- to 3-inch-thick layer of straw or shredded bark after the ground freezes.
Peonies should be divided and transplanted in the early fall every few years. To divide, dig the plants, cut off the foliage, hose the dirt off the roots, and divide into sections, each with at least three eyes (pink growth buds). When you replant, make sure the eyes are no deeper than 2 inches. If they're deeper, the plant may not bloom. Prepare the soil before transplanting by digging deeply to loosen the soil so the roots can penetrate easily. Peonies like full sunshine and lots of moisture during their blooming season.