22 October 2007
Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578
October is good time of year to plant or divide peonies. Herbaceous peonies (Paeonia sp.) are popular garden perennials. The foliage is attractive all summer long and plants bear eye-catching, beautiful, often fragrant, flowers. In addition, the plants are long-lived, require little care, and are practically pest-free.
Peony plants form rounded clumps, 18 to 30 inches in height, with flowers form May to June. Peony blossoms may be single, semi-double, or double, and come in a range of colors varying from white and cream, to pink and red. Remove flower heads after they have shattered, but before seed heads are formed to ensure continued, high-quality foliage. After flowering, a complete fertilizer should be scratched lightly into the soil, being careful not to disturb the roots. After the first killing frost, cut stems back to the ground and remove any weeds encircling the plant.
Be watchful for aphids and other insects on developing foliage and flower buds. Ants are frequently found on peonies, being attracted by the sweet, sticky substance which is exuded from the buds. While they do no harm themselves, it is very probable that ants carry the spores of fungal diseases from one plant to another when such spores are present.
Peonies prefer deep soil that is well drained, slightly acidic, and rich in organic matter. At planting time, a generous mixture of well-rotted manure or compost incorporated into the planting hole will benefit plants.
Peonies perform best in full sun. They will grow in light shade, but flowers will be fewer and smaller. If possible, select a place where high winds cannot buffet the heavy blossoms.
Division of existing plantings and the establishment of new plantings should be done in the fall. Peonies can be left undisturbed for many years. Plants should be allowed to become established (one to two years) before cut flowers are taken.
When one desires to divide a peony, dig around the entire plant to remove is as a whole. Using a sharp knife, divide the tuberous roots into sections each with at least three "eyes." To plant, dig a two-foot hole and enrich the topsoil with organic matter and bone meal. Do not use peatmoss in the planting whole which can keep the soil too wet causing root rot. Set divisions about three feet apart covering the eyes with one to two inches of soil. Mulch new plantings and keep watered until frost hardens the soil. When the ground freezes solidly, cover with evergreen branches.
You might try this fertilizing practice on peonies: In early spring, apply one fourth cup of a 5-10-5 fertilizer as the developing shoots reach about 10 to 12 inches. Make a second application just as they complete flowering. Avoid getting fertilizer on stems. Gently scratch the soil to work the fertilizer down a bit. However, remember peonies do not like to be disturbed once they are established.
Virginia Cooperative Extension is offering Master Gardener Volunteer training in Albemarle, Fluvanna, Greene, and Louisa counties in 2008. Please contact your local Extension office for more information or to register for these classes.
For more information about this and other landscape topics contact your local Virginia Cooperative Extension office. The local Virginia Cooperative Extension office numbers are Albemarle 872-4580, Fluvanna 591-1950, Greene 985-5236, Louisa 540-967-3422, and Nelson 263-4035.