Spring brings the first garden colors of shy crocus, nodding daffodils and sturdy tulips. It ends, though, with the extravagant show of an old-fashioned garden favorite: Paeonia. Manage peonies properly and they will reward you with a riotous display of blooms for decades. These tough, hardy plants will reward the patient gardener from growing zones 2-8 and require little of the attention demanded by their cousin, the rose, which is next in line to bloom in June.
Plant peonies in the right place. Although the species as a whole is adaptable to a wide variety of growing zones, find peonies grown within a zone of your garden’s conditions—and preferably in the same area of the country. All peonies need full sun and well-drained soil; never plant them where their “feet” can get soggy. They do need plenty of watering, though, during their first summer and throughout dry springs and hot summers.
Plant pot-grown peonies from the nursery anytime after the heat of August and divide garden plants when the trees begin to change color. Dig a large hole and fill with garden soil amended with peat moss or compost; a medium that allows air circulation and quick drainage will encourage roots to grow and establish the plant quickly. Add a handful of bulb fertilizer or a low-nitrogen fertilizer (5-10-10) for use in the flower garden to the hole before filling. Plant the tubers with the “eye” (the bud from which the stems grow) no deeper than two inches. Like iris, the peony does not bloom well when buried too deeply to catch the first warmth of spring.
Mulch peonies in the spring after they bloom to keep their roots cool during the summer. Use a two-inch “summer mulch” of compost and garden soil. Remove the mulch in the fall and sprinkle a handful of fertilizer on the surface the first few years the plant is in your garden. Once peonies are established, they will increase in bloom each year with little attention except grooming.
Support your peonies and keep them trimmed. Put wire cages around peony plants or tie string between four stakes to support the stems before they start to produce flower buds. Some peonies grow to 4 feet tall and their large flowers pull stems over, especially with rain weighing them down. Pinch off “side” blooms with your fingernails to leave only one bloom on each stem.
Cut plenty of flowers but be careful to leave about two-thirds of the stem on the plant; it will need foliage to produce food for next year’s blooms. When the plant finishes blooming, trim any untidy stems just enough to make a neat shrub for the garden.
Clean out summer mulch in the fall and cut stems down after the frost kills them. Any diseased foliage should be removed when it is observed but all foliage should be removed and destroyed in the fall; dead foliage can carry botrytis or phytophthora blight. Destroying foliage also controls leaf spots and mosaic virus. In areas where winter temperatures drop below 20 degrees below zero with little snow cover, peony beds can be mulched with evergreen boughs for protection but peonies generally need little winter protection.