Home » Plants & Animals » Northern Gardening » The Peony, A Queen Among Perennials for the North

The Peony, A Queen Among Perennials for the North

© Mary Henry

For every tender perennial I crave from warmer parts of this world, there is someone there who envies us the magnificent peony. Not even roses can match it for sheer flower-power when those buds open into cabbage-sized blossoms of red, rose, pink, cream, yellow, white, or burgundy. Some varieties are even deliciously fragrant. This beautiful plant is one of the oldest flowers in cultivation. It has been grown and cherished in China for over four thousand years. It's not only beautiful, it is hardy in zone 3 and, when well grown, can live longer than the gardener who planted it. Though flowering lasts only about two weeks, the foliage is very attractive all season from the warm reddish spears that push through the ground in early spring through the summer's handsome green shrub-like form to the burgundy-foliaged fall finale. Peonies can be used as focal points in perennial borders, summer hedges where snow must be piled in winter or even as specimens in a foundation planting. They prefer not to be planted in a lawn as lawn fertilizer is too high in nitrogen for their health.

Used first for medicinal purposes and thought to ward off devils (some species have seeds that glow in the dark), it became known as the Benedictine Rose after monks introduced it to monastery gardens north of the Alps in the early Middle Ages. The peony had received its name in Greece earlier as the namesake of Paeon, the physician to the Gods. The genus Paeonia is found all over the northern hemisphere. There are native species that grow in areas of Oregon, Idaho and California.

There are both herbaceous perennial and "tree" species. Despite the name they are shrubs, the largest (found in Britain) are only eight or nine feet high. The perennials, especially Paeonia lactiflora, are the most widely grown and are available in many flower forms: single, Japanese anemone, semi double and fully double. The fern-leaf peony, P. tenuifolia, is becoming more popular too, though it hasn't had as many variations developed yet. Hybridizing has produced a massive list of cultivars and the work goes on around the world. Minnesota has had its own share of talented breeders and, by looking around, varieties can be found that were bred here.

I have seen elaborate sets of instructions for altering the environment to grow peonies where there is little winter cold. We definitely don't have that problem, so their culture is really very simple in the North if you follow a few basic rules. They even prefer their soil sweeter (less acid, around pH 7) as ours often is. Fall is the best time to divide, plant or transplant bare-root peonies. Choose a location in full sun with good well-drained soil. Dig a generously wide, but not overly deep hole. Campbell's Nurseries in Lincoln, Nebraska have developed a simple way to insure that the "eyes" are not planted too deeply. They recommend planting the peony with the uppermost eye at ground level. After it has been watered thoroughly to settle the soil, mound two more inches of soil over the new planting for the first winter. The following spring rake the excess off or allow the rain to wash it away naturally. Do not fertilize when planting. Wait until spring after flowering. Use a balanced fertilizer (not one high in nitrogen). Slow release forms seem best. Don't use manure on peonies as it seems to promote their only real problem: Botrytis. This fungal disease is best prevented by removing and disposing of all foliage after frost has killed it in the fall and insuring good drainage of the soil. In spring, if your plant has shown signs of infection in the past (leaves developing large brown patches and shrunken, aborted flower buds), buy a fungicide labeled for use on peonies. Drench the soil with it when the new shoots first appear and again after flowering. If the symptoms are first noticed in summer, also use the drench in the fall when removing the spent foliage.