uestion:
How do you grow herbaceous peonies?
Question:
How do you grow herbaceous peonies?
The following answer refers to the common herbaceous peonies, and not to tree peonies:
Herbaceous peonies are beautiful, fragrant, late spring/early summer blooming flowers that are fully hardy in our winters. The ancient Chinese first enjoyed them over 2500 years ago. The flowers of today’s hybrids may be single, semi-double, double, or Japanese (wide petals with a puffy center) and come in a wide range of colors...pink, red shades, yellows, peach, lavender, and white. Sorry, blue is not available. Double flowers are more fragrant than singles; pink shades tend to be more fragrant than other colors. Some varieties are so loaded with heavy flowers that they need peony rings or other supports, especially when blooming. Add supporting structures early in the spring before leafy growth appears. Peonies are long-lived; some farmhouse clumps are over 100 years old and have not been divided. They are low maintenance plants that resist deer and drought. Most varieties bloom for only 7 to 10 days, but by selecting a range of different cultivars – early, mid-season, and late bloomers - you can have blooms for up to six or seven weeks. They grow 2 to 4 feet tall and wide. After the flowers fade, the dark green foliage provides a nice backdrop to shorter annuals or perennials. Fall foliage color is often reddish maroon.
Plant container grown peonies in the spring or fall. Plant bare root peonies in fall about six weeks before the first hard frost. Choose a sunny (or lightly shaded), well drained location for your peony bed. Rich, moist soil high in organic material is best. Dig a hole big enough to fit the roots; spread out the roots if they are crowded. Add compost or other organic fertilizer to the planting hole. Always plant peonies so that the buds are only one inch below the soil surface. Firm soil well to remove air pockets. Water well.
Space plants at least 4 feet apart. Fertilize established plants around the crowns with organic fertilizer, well-rotted manure, or Milorganite in the fall to provide nutrient and to improve the soil structure. Granular fertilizer may be used instead, but choose one that is lower in nitrogen (the first number on the fertilizer container) and higher in phosphorus and potassium (the second two numbers). Avoid placing fertilizer right on top of the crown. Water when new growth comes up in the spring and deeply during dry spells. Remove all spent flowers, so that the plant does not spend energy forming seeds. Mulch well during the first winter; mulch (2-3”) during the growing season to discourage weeds and to reduce the need for watering. Avoid cutting the shallow roots when weeding.
As long as they have enough growing room, established plants do not need to be divided very often, if at all. If you do choose to increase the number of your plants, divisions may be made in early September and planted bare root. Carefully lift the entire plant, wash the roots well to remove soil, and use a sharp knife to divide the roots. Use care in dividing your plants since the eyes (buds on the roots) are fragile and can be rubbed off easily. Cut so that 3 to 5 eyes remain on each piece and several strong roots 4 to 6 inches long are present. Replant as soon as possible. It may take 3 years for the new plants to bloom. Removing all flower buds during the first few years helps the plant make a good root system.
Sometimes peonies do not bloom. Possible causes are:
(1) Not enough sunlight.
(2) The peony is planted too deep (over 2 “), the plant has settled too deep, or added soil covers the eyes.
(3) The plant is too young and not fully established.
(4) Over-fertilization, especially with excessive amounts of Nitrogen, encourages leafy growth over flower formation.
(5) Competition from nearby trees and roots, or crowded plants.
(6) Disease, such as botrytis blight, can infect plants in the spring and cause gray, fluffy fungal growth on stems, buds, and leaves. Black or brown spots may be seen. Remove diseased tissue, cut foliage as low as possible without damaging root buds, and use Mancozeb or Cleary 3336 for control in severe cases. Follow label instructions carefully. Disinfect your pruners after use with a 10% bleach solution (1 part bleach, 9 parts water). Practice good garden sanitation by cutting away all dead stems and leaves in late fall; cut as close to the ground as possible without injuring the eyes of the plant. Destroy dead material; to reduce disease, do not compost.
(7) Sometimes small sucking insects, called thrips, will attack the flower buds. Control by spraying with an insecticidal soap.
(8) Late freezes will sometimes damage the flower buds.
Happy Gardening,