Peonies display their luscious flowers for a few weeks starting in spring. If you need to transplant peonies, the best time to do so is in the fall after they finish blooming and are approaching dormancy. The transplanted peony may not produce as many, if any, flowers as before it was transplanted. Expect it to spend its first year settling in, the second year expanding, and then bloom the third year at its new location.
Water the peony the day before you plan to transplant. Watering the ground can make it easier to dig and by watering the day before, the water will have time to soak down to the base of the roots. Cut the foliage back to about 3 inches above ground. Cutting back the top provides something to hold on to in the transplant process and is also a step toward winterizing peonies.
Dig the transplant hole 24 inches wide and 18 inches deep in a full sun location that has good drainage. The location should be away from downspouts and not in a low area where rain water may pool. Add a slow-release organic fertilizer or organic compost to the hole.
Dig around the peony about 12 inches from its center and 12 inches deep to ensure all the roots are included as you dig. Hold the plant by the 3-inch top and run water over the roots to remove all the dirt.
Take the roots of the peony to its new location. Hold the root by the top and align the crown (where the roots meet the top) at ground level. The eyes (buds on the main root) should be less than two inches below ground level. Back fill the soil, spreading the roots as you fill the hole.
Water thoroughly. Add about 2 inches of mulch over the plant for winter protection. Remove the mulch in late winter or early spring. Water the new plant the following spring through summer about every 10 days if there is no rainfall.