How to Prune Herbaceous Peonies
Herbaceous peonies come into full bloom in late spring and keep their large red, pink, or white blossoms until early fall. Since peonies are perennials, they will come back every year with bigger blooms and better health when properly pruned. Pruning encourages new stem growth, creates better air circulation to discourage insects, and maintains a tidy appearance.
Things You’ll Need
- Hand shears
- Hedge trimmers
Pinching and Disbudding
- Pinch back the terminal bud when the plant is first purchased. The terminal bud is the end piece of the vegetative stem. You can also remove the first batch of leaves with this bud.
- Once budding begins again, examine the stems of the peony plant and identify the primary buds by locating them at the tip of the stems.
- Use your fingernails to break away all the buds growing to the side of the stem. Leaving the single, primary bud will cause the plant to focus on one bloom, thus becoming large and lush.
Thinning and Cutting Back
- Locate, at ground level, the branches of the peony bush you wish to cut away. These branches should be ones that are either discolored, weakened, or overly crowded.
- Remove these branches at ground level using the hand shears and discard. Continue to clip the plant to create an attractive profile, such as a rounded bush.
- Completely cut back the entire peony, using the hedge trimmers, until only the shoots are visible from the ground, at the end of the blooming season, in mid to late September. This will increase next year’s productivity. Leave approximately 1 to 2 inches of the plant above ground level.
Tips & Warnings
If you cut back directly after the initial bloom, your plant has a great chance of dying off. Cutting back should only be done to prepare for the winter season. If you have disbudded to increase bloom size and your blooms are weak or not coming in at all, try a reduced-nitrogen fertilizer. High nitrogen levels will cause peonies to suppress their blooms.