The best time to cut back herbaceous peonies is in the fall, between October and November, after the first hard frost and when the foliage has turned yellow. Cut the peonies back to about an inch (2.5 cm) above the ground. This timing allows the foliage to gather enough energy to support next year’s growth and helps prevent fungal diseases like powdery mildew that can survive on dead leaves over winter. Avoid cutting peonies back too early in the summer or late summer, as it can reduce blooms the following year. For tree peonies, the pruning schedule is different; they should be pruned right after they bloom in late spring rather than in the fall. Only remove spent flowers and cut back the top growth by about one-third in fall if needed, but do not cut them back to the ground. Itoh (intersectional) peonies should follow a similar prune-back schedule as herbaceous peonies in the fall, cutting down to the woody part but leaving the wood intact. In summary:
- Herbaceous peonies: Cut back in fall after first frost, when foliage is yellow, about 1 inch above ground.
- Tree peonies: Prune right after blooming in late spring, not in fall.
- Itoh peonies: Cut back herbaceous part in fall, leave woody part.
This care approach promotes healthy plants and vibrant blooms next spring.
