The Best Time to Divide & Transplant Peonies

Characteristics

• Peonies vary in size and color. The predominant colors are white, pinks and deep rose. Established older peonies may get up to 5 feet tall and come back year after year with new vegetation and flowers. The loose petals of the flowers stem from nearly fist-sized buds that may decline in number as the plant ages. The root spread may span 4 feet in width and 18 inches in depth, making them efficient at water and nutrient gathering. The root size also influences the ease of transplanting or moving the plant.

Transplanting

• Peonies can be moved at any time of the year, but the best times are early autumn or late summer. These periods give the best chance of reestablishment because the plant has had time to store energy in its roots. The plant has a brief dormancy during these times before it starts active root development again in late autumn. Digging out an older peony for transplanting means digging deep and wide to gather as much root as possible. Plant the peony as deeply as it was originally planted and supplement with water the first two or three weeks. The plants need to be fertilized after the following season's bloom time to enhance their growth.

Dividing

• Peonies have fleshy roots in which they store plant sugars for seasonal growth. These roots can be divided into sections in which each root has three to five eyes or pink protuberances of the root. Cut the roots apart with a sharp knife, and plant the divisions in rich organic soil with excellent drainage. Bury the roots only 1 or 2 inches deep with a spread of 2 to 3 feet between roots. Mulch with organic material over the winter to protect the roots and pull the mulch away in spring as soon as sprouts appear.

Saving Roots

• Peonies grow from bare roots when they are purchased, divided or traded. The roots may be planted in fall before a freeze or in spring just after the worst cold has passed. Peony roots that are overwintered indoors are stored in sphaghum peat moss in a cardboard box or paper bag. They must be held where there is minimal moisture and cool, but not freezing, temperatures. Plant the roots in spring but be advised they might not sprout until the following year. The optimum time for them to root is in fall, and they need cooler temperatures and supplemental water to produce vegetative growth.