The beautiful fragrance and delicate flowers of peonies quickly make then a welcome plant for almost any garden. If you are noticing a decline in blooming flowers, however, it may be time for digging and dividing the peony to relieve strained roots. Then you'll see flowers again. For best results, dig a three- to five-year-old peony after waiting for mid-fall to come before you begin.
Wet the soil around your peony thoroughly 3 to 4 days before you plan on digging it up. You don't want the soil to be too dry or too wet; you want it moist when you go to dig the peony.
Cut off any stems with your hand pruners, with a horizontal cut, to shorten them to only 2 to 3 inches tall. Clear away stems and any dropped leaves from around the base of the plant.
Use a digging fork or pitchfork to dig up the entire peony intact, being careful not to slice into the root ball with the tines of the fork. Gently raise the peony and set it on the ground. Allow it to rest there for 3 to 4 hours to allow the roots to soften slightly.
Rinse off the root ball to remove excess dirt and to reveal the eyes of the peony, which rest just under the surface.
Cut the root ball or crown of the peony into smaller divisions with a sharp knife, or use your pruners, if they are pointed, by cutting straight down through the crown without damaging the roots. Each division should have no fewer than three eyes, so plan your divisions carefully.
Replant each division in an area of full sun, and keep each peony 2 to 4 feet apart if planting together. Each new peony should be planted with the eyes pointing upward. Make sure there is only an inch of soil covering the eyes.
Keep the new divisions well watered so the soil stays fairly moist as it recovers from separation. Most peonies will thrive if given an inch of water each week, total, when you add manual watering and rainfall.