There are over 30 varieties and many new hybrids of Paeonia lactiflora, also known as the common garden or Chinese peony. These perennial herbaceous plants are hardy, drought tolerant, low maintenance and long-lived. They are also deer and rabbit resistant and subject to very few pests and diseases. Herbaceous peonies come in many shades including apricot, coral, white, red, pink and lavender. Many varieties are fragrant. They deserve to be a beloved staple of every garden bed and border.
Growing Conditions and Culture
Buy peonies in pots or root form (these are purchased in fall) from a reputable grower or nursery. Plant immediately in fertile soil, choosing a site with good drainage and gets 5 hours or more of direct sunlight per day. Space each plant 3 to 4 ft apart. Sprinkle some compost or aged manure into the planting holes mixed with a handful of bone meal or 5-20-5 plant starter diluted with water as per instructions. Fill the hole with soil to a level no more than 2 inches above the plant crown (the part of the plant that has buds or ‘eyes’ looking like pinkish roots). Peonies planted too deeply won’t get enough winter cold to flower. Water frequently until established. In the growing season fertilize lightly with half strength liquid fertilizer or sprinkle composted manure around the perimeter of each plant but not over soil where the stems meet the ground. Older varieties will need peony cones or stems to prevent them from bending over in wind and when the plants are heavy with blooms. After flowering, remove the spent blooms. In fall, after the first frost, cut foliage and stems back to 1 inch above the ground. Discard stems and foliage but don’t compost them because fungal disease can overwinter in the plant material. Don’t mulch or use other winter protection which can hinder next year’s blooming performance.
This should only be necessary if a plant has to be moved or in the case of an older peony no longer blooms in the centre. Divide peonies in early September if possible. Dig up the plant, shake off loose soil around the roots and place in a shady spot for a couple of hours. This will make the roots easier to divide. Use a shovel blade or sharp knife to divide each plant into several pieces. The divisions should have roots and at least 3 to 5 ‘eyes’ each. The pieces should be fairly small as they will flower sooner than larger pieces when replanted. Plant the divisions immediately. If this is not possible, store the roots of the divisions in moist but not wet peat moss.
Why Peonies Don’t Bloom
● Planted too deeply
● Plant is too young
● Plant not getting enough hours of full sun per day
● Plant divisions too large
● Root system damaged by moles or other animals
● Overfertilization, underfertilization, poor soil or poor drainage
● Buds fail to open due to a late frost, drought, or disease
Pests and Diseases
Ants may feed on the nectar of unopened buds but they are harmless to the plants and most will be gone when blossoms are fully open. Botrytis blight or gray mold is a fungal disease and the most serious peony problem. It is most likely to occur during a very damp and rainy growing season. Stems have a water-soaked cankerous look, young shoots rot off at ground level and foliage may wilt suddenly. Destroy all infected material. Powdery mildew may occur in summer. It is often the result of the overuse of automatic or other sprinkler systems. It will not affect flowering which usually occurs earlier. A solution is to cut back on watering.
For further information on garden peonies, consult the Canadian Peony Society’s website www.peony.ca