How to Keep Peonies
Peonies appear as two different types of perennials: garden peonies (Paeonia valbiflora or Paeonia officinalis) and tree peonies (Paeonia suffruticosa). Garden peonies reach 3 feet tall and produce five different types of flowers. Tree peonies grow as cold-hardy shrubs that remain standing through the winter. Both species bloom in the spring at varying times, depending on the cultivar. They produce large blossoms in coral, red, white and yellow among other colors. Despite their structural differences, garden and tree peonies require similar care.
- Moderately Easy
Things You’ll Need
- Rototiller (optional)
- 10-10-10 fertilizer
- 5-10-10 fertilizer
- Soft-cloth strips
- Grow peonies in full sun for eight hours per day. As a second option, place them in a mostly sunny site with a two to three hours of shade, preferably in the afternoon.
- Plant peonies in well-aerated soil. Incorporate 3 inches of compost to a depth of 12 inches for a site that drains water within one hour of irrigation or normal rainfall. Use a shovel or rototiller. Add ¼ cup 10-10-10 fertilizer to the bottom of each planting hole.
- Build a 2-inch-deep mulch ring around the base of each peony, using wood chips, dead leaves, grass clippings or another organic materials. Put the mulch in place each spring to conserve moisture, insulate the roots and suppress weeds. Rake the mulch away from the plants and discard in the fall to eliminate overwintering places for pathogens. Build a new mulch pile in early spring.
- Feed each peony plant ½ cup 5-10-10 fertilizer when the stalks reach 2 inches tall in the spring. Do not let the feed touch the stems. Water it in after application.
- Stake plants that droop under the weight of large flowers, using soft-cloth strips tied loosely to the stems. Bury the support 6 inches into the soil behind the peonies.
- Deadhead peonies with your fingers or a pair of shears as soon as the flowers fade. Deadheading prevents seeding and reserves the plant’s food supply for flower production. Prune just below the dead flower head, retaining all foliage.
- Trim garden peonies back to 3 inches after the first hard frost of the season, to prevent fungal disease. Leave tree peonies intact.
Tips & Warnings
Remove all side buds and retain the terminal ones to induce the production of large flowers.
Divide peonies in the fall when they become crowded, every 10 to 15 years, according to North Carolina Cooperative Extension Service.