Peonies are a long-standing favorite among gardeners, with their rich foliage and showy blossoms in a variety of colors. Peonies are easy to grow, as long as they have adequate growing room, plenty of sun and regular feedings. Because peonies are herbaceous perennials, they renew themselves completely each growing season. Proper peony trimming will protect a peony plant from disease and keep it growing and thriving for many years.
Use the pruning shears to cut back all the stems of the peony plant in midautumn when the plant has wilted and faded from chilly autumn temperatures. Cut the peony plant to a height between soil level and 3 inches.
Discard the peony shoots in a compost pile or in a trashcan.
Sprinkle garden lime generously over the soil where the peony plant was growing. Add a 1-inch layer of compost above the lime.
Rake the lime and compost into the soil. Add no mulch to the soil above the peony roots. Peony roots do not need to be protected with mulch.
Encourage large peony blossoms by removing side buds from the stems as they appear in the spring. Leave the main "terminal" buds on each stem, but trim off any buds on smaller stems that branch off from the main stems.
Allow the peony plant to grow as it desires throughout the remainder of the growing season. No other trimming is necessary until you must cut back the peony plant again the following autumn.