Peony's a charming lady, she doesn't like a spot too shady; likes to live out in the light, dressed in red or pink or white. --Elizabeth Gordon
Peony plants are some of the oldest perennials in cultivation. There are woody small shrubs (euphemistically referred to as tree peonies) in addition to the herbaceous perennial types. Herbaceous peonies assume a shrublike stature at 2 to 3 feet in height and width. Their leaves and stalks die to the ground after a killing autumn frost, but the rootstock remains very much alive, ready to send up those telltale red shoots the following April.
In spite of their delicate floral appearance, peony plants are strong, long-lived, and completely cold hardy, perfectly suited to midwestern weather. They resent disturbance and can live for 50 years if provided with their simple requirements. Their size and attractive habit make them suitable companions to all other border plants such as dwarf conifers, bulbs, and both early- and late-blooming perennials. Even though they bloom relatively early (May to early June), their stocky forms and ornamental foliage remain attractive all summer, well into autumn, when their leaves turn red as temperatures dip. At this time they are particularly valuable to late-blooming, prone-to-toppling perennials like asters, that will benefit from the healthy support system provided by the solid peony bushes.
Peonies are classified by the type of their blossoms or the time they bloom. Flowers are single, anemone, Japanese, semidouble, double, or bomb. The single, anemone, and Japanese forms feature large, cupping petals that surround a center of bright yellow stamens (although a few of the Japanese flower centers are light and dark pink). The double forms hide their stamens inside never-ending petals; and the bomb flowers are recognizable by a flat outer row of guard petals, inside of which sits a fat "bomb" of tight petals. The anemone form's flowers are similar to doubles but the center petals are all narrow. The inner and outer petals are the same color, while the Japanese forms feature flowers with the narrow center petals in a contrasting color to the outer, larger petals. The hybridizing of peonies is an ongoing science, with new introductions marketed every year.
Peonies can be grown as specimen plants strategically placed in long or curving borders where they provide early structure as perennials begin to emerge. They can be massed in the back of low borders where they contribute an early showy flower display and then serve as a green backdrop for colorful bulbs, annuals, and perennials. By carefully selecting one single variety and placing plants side by side in a long row, gardeners can create a novel and quite ornamental peony hedge.
To extend the enjoyment of the flowers, choose a few early-, mid- and late-season types so that they don’t all bloom at once. While most colors are in the pink, coral, and red tones, there have been interesting developments in yellow. Consider how you want to use this plant before being swept away by the hundreds available locally and through specialty catalogs. Plant the fragrant ones close to a door or patio or use them as cut flowers. Never cut more than 25 percent of the blossoms from a plant in one season, taking care to cut short stems, leaving as much foliage on the plant as possible.
Plant peonies in the spring as potted plants or in the fall as bare tuberous roots. Cultivate the planting site thoroughly, add compost, and water well. In the fall, set the swollen roots no more than 2 inches below the soil surface. If planted too deeply, the peonies will fail to bloom. Mulch the area over winter just for the first year. Remember to cage your plants when they are 10 to 12 inches tall to support the heavy blossoms.
Peonies are susceptible to a variety of fungal blights that are exacerbated by wet, cool springs. Symptoms include blackened, splotched foliage; dark, dried buds that never open; or streaked stems. Approved fungicides are available and must be applied when the new shoots are 2 to 4 inches tall. Gardeners can reduce the chances of infection by spacing plants far apart, planting in well-drained soil in full sun, practicing good sanitation, and removing all dead foliage from the garden at the end of the season. So little effort for such heart-stopping beauty!