The peony plant (Paeoniaceae) is one of the showiest and most prolific bloomers in the perennial border. Valued for its cut flowers, which develop large multi-petal blooms on slender stems, and its deep green foliage, the peony plant spreads by way of its root system. Transplanting a mature peony plant isn't difficult when you cut the large root cluster into smaller segments, each with the potential of producing a hardy new full-size peony plant.
Cut the long peony stems with garden shears, to within an inch of the base in early fall, after the growing season is over and the stems are a bit droopy.
Dig out the established root system, dividing it into smaller portions as you go. A mature peony root system may consist of dozens of tightly crowded root clumps, many with their own stems.
Divide the root system, keeping approximately four roots in each clump. Select clumps that have a few established "eyes." These are the nodules that produce stems. Wash the soil from the clumps and trim away unsightly or withered root sections.
Select a new location with rich, well-drained soil where the plants will receive full sunlight and dig a hole approximately 2 ft. deep and 2 ft. in diameter, filling it with rich topsoil or a soil and organic matter mix.
Position the peony root in the center of the hole, with the crown approximately 2 in. below ground level. The eyes, or nodules, should be at the top. Fill around the roots and cover with lightly packed soil.
Water the new transplants as often as needed to keep the soil moist but not soggy. The peony plant will send out tiny roots very soon, establishing the plant in its new location before winter.