Plant Some Peonies This Fall and Be Rewarded in Spring

Early fall is the perfect time to plant, transplant or divide peonies in your landscape. Peonies are herbaceous perennials that have few rivals for their floral display and foliage. Their exquisite, large blossoms, often fragrant, make excellent cut flowers, and the foliage provides a lovely background for annuals or other perennials after the blossoms have faded. 

There are four types of peonies that are generally grown in the home landscape; the woodland peony (Paeonia japonica), the woody tree peony (including Paeonia suffruticosa), the garden or herbaceous peony (Paeonia spp. hybrids), and the intersectional peony (also known as the Itoh, a hybrid of the garden and tree peonies). Peony flowers are available in a wide range of colors, from pristine, pure white, to soft and deep yellows, to every shade of pink imaginable, to salmon, oranges, reds, maroons, and purples. There are even peonies in shades of green from chartreuse to pale green-yellow that offset some of the red and burgundy shades beautifully. And if the color options aren’t enough of an incentive, consider the many flower forms of peony. The American Peony Society recognizes six forms, although there are some flowers that bear more than one characteristic. 

Site selection is an important step. Peonies thrive in full-sun locations, out of strong winds, where they can receive eight or more hours of sun each day. They need fertile, well-drained soils with a pH between 6.5 and 7.5. As Connecticut soils tend to run acidic, a soil test performed by the UConn Soil Nutrient Analysis Laboratory is recommended prior to planting. Any fertilizer amendments should be mixed into the soil, 2 to 3 inches below the tuber or transplant.  

Dig a hole that is large enough to accommodate the roots and incorporate aged organic matter in the bottom. Peonies are generally sold as bare-root tubers. Select only specimens that are firm and free of rot. Soft spots may be trimmed with a knife. Place the tuber in the prepared hole so that the eyes (the small, red-colored buds) are 1 to 2 inches below the soil’s surface. (Planting too deeply will prevent the plant from blooming.) Backfill the hole and water well. A light layer of mulch may be applied to conserve moisture and minimize weeds.

Ongoing care and maintenance of peonies includes providing support for tall, double-form hybrids that can become top-heavy when in bloom. Remove any faded blooms to prevent seed development by cutting the stem back to where it is hidden by foliage. Plants may be mulched during the growing season to conserve water and minimize weeds, but after the first year peonies should not be mulched during the winter. 

Peonies may incur some fungal diseases, especially during warm and humid weather. Planting in full sun with adequate air flow around the plants may help, as will removing any plant debris. For the diagnosis of peony diseases and suggested controls or other horticultural queries, contact the UConn Home & Garden Education Center at 877-486-6271, go to www.ladybug.uconn.edu or call or visit your local Cooperative Extension Center.

Susan Pelton writes from the UConn Home & Garden Education Center.