Peonies range in color from white to dark maroon, and can produce a variety of flower and leaf sizes and shapes. These perennial plants can be placed in beds by themselves or can be used in conjunction with a variety of other types of flowers. Once established, peonies will grow back and bloom year after year.
Peonies typically should be planted in late summer of early fall. Before planting, till the soil and apply a basic flower fertilizer at a rate of 1 lb. per 25 square feet. Plant peony root cuttings with the eyes of the plant approximately 2 to 3 inches below the soil surface, being sure to leave 3 to 4 feet between each plant. Peonies do best with full sunlight and limited shade, and away from large trees or shrubs that may monopolize water and nutrients.
Start fertilizing the peonies during early spring at the first sign of growth. Place one tablespoon of fertilizer around the flowers and work it into the surrounding soil. Providing adequate amounts of fertilizer to peonies plants during early spring is especially important to ensure foliage and bloom production.
After approximately 10 years of growth, the flowers of peony plants will become small and the stems will appear crowded. At that time, it is necessary to divide the plants to maintain health and growth. To divide roots, loosen an 18 to 20 inch perimeter of soil around each of the plants, and carefully remove the peony. Let the roots of the plant dry in the sun, and shake off loose soil. Carefully clean the roots to remove any stubborn soil, and trim to 2 inches for replanting. This process is preferably done in the early fall when the plant is entering dormancy.
During dry, summer months, it is important to regularly water peonies, even after they are done blooming for the season. Consider mulching around your peonies if it is exceptionally dry, as the mulch will help retain soil moisture.
Preventing Peony Disease
If you notice any leaf spots or root rot in your peony plants, cut off any damaged leaves and replace the surrounding soil with fresh dirt. In addition, it may be necessary to sterilize the soil with a formaldehyde solution. If the flower is seriously damaged, remove the plant from the soil and place it in a 30 minute bath of 120 degree water to kill the disease; discard the plant.
Peony buds and flowers attract ants, and although that can be an annoyance, it is a normal part of cultivating peonies.