Few perennial herbaceous plants can compete with peonies in terms of their floral display and foliage. The foliage serves as a backdrop for annual plants or other perennials, and its lovely, big blossoms, which are frequently scented, make great cut flowers. Paeonia japonica, Paeonia suffruticosa, Paeonia spp. hybrids, garden or herbaceous peonies, and intersectional peonies are the four types of peonies that are typically planted in the home landscape (also known as the Itoh, a hybrid of the garden and tree peonies).
The floral shape of peonies is used to classify them. All peony have a center of stamens or modified stamens, and five or more big outer petals called guard petals.
Broad petals mixed with pollen-bearing stamens make up the centers of semi-double forms.
The semi-double anemone type may have many rows of guard petals enclosing a central area with thin, petal-like features.
Japanese types resemble anemones but have staminodes in their cores instead of stamens that make pollen.
The overlap of the four varieties often begins in late spring with the white-flowered woodland variety for two weeks, followed by the tree peonies for two weeks, the herbaceous for two to three weeks, and finally the intersectional hybrids for two to three weeks. Flowering can be prolonged for six to eight weeks by choosing and planting early, mid, and late season bloomers. All colors but blue are available in flowers.
Peonies can reach heights of two to four feet. While tree and intersectional kinds typically don’t require support, tall, double hybrids frequently require it in the form of metal peony rings. They feature thick, emerald leaves.
Peonies’ Beneficial Function Peonies have a useful function in addition to adding beauty to a landscape. Unopened peony flower buds release extrafloral nectar, which draws the beneficial Spring Tiphia wasp, Tiphia vernalis. The Summer Tiphia, T. popilliavora, consumes the wild carrot’s nectar. By depositing their eggs on the side of the growing grubs, these wasps parasitize the grubs of Japanese and Oriental beetles. When the larva hatches, it firmly attaches itself to the grub’s side and starts to feed on it, killing it in the process. Additional details are available on the UConn IPM website Ornamental plants that support white grubs’ natural enemies.
Site choice Peonies prefer full light (8 hours or more per day), but they can also take part shade (such as 5 to 6 hours of sun each day), however they could have fewer blooms. Fertile, well-drained soils are preferred by peonies. They dislike having wet feet, so thick clay soils are not a good choice because the roots would quickly decay in such soil. On the other hand, soils with a high amount of sand will drain too quickly. The optimum growth occurs in soil that is deep, rich in organic matter, and has a pH range of 6.5 to 7.5.
With a few exceptions, they are hardy from zone 9 to zone 3. Peonies need a minimum of 6 weeks of temperatures below 40°F in order to flower in the winter. The amount of chilling hours needed for each cultivar is rated in flower catalogs and internet vendors. When it comes to Connecticut, where the zones span from 7a to 5b, this is typically not an issue.
They can be planted with spring flowering bulbs as well as iris, day lilies, chrysanthemums, and hardy asters for a straightforward border with year-round color. A multipurpose perennial, peonies are wonderful backdrop plants for low annual blooms.
Plant on a northern exposure and avoid mulching in the winter to promote flowering. Due to root competition from neighboring trees and bushes, flower size will diminish. Strong winds should be protected from, but the planting area should also be well-aerated to minimize disease issues. Avoid areas that have previously been used to cultivate peony.
Planting The greatest time to plant, transplant, or divide peony is in the early fall, but you may also do it in the spring as soon as the soil is workable. It’s possible that spring-planted tubers won’t bloom until the following year. At least two feet and four feet, respectively, should separate dwarf and standard varieties.
Beginning with a soil analysis from the UConn Soil Nutrient Analysis Lab will allow for the addition of any amendments at planting. Test your soil for vital nutrients every three years. Peonies don’t need a lot of fertilizer, and too much nitrogen will actually make them blossom less. Fill the bottom of the hole with 1/4 to 1/2 cup of 5-10-10 fertilizer per plant. Instead of putting amendments in the soil that will be a few inches below the tuber because the deep roots will grow down into it, avoid putting fertilizer in the soil that will be around the roots. Superphosphate or bone meal may also be added in the amount of a half cup at planting.
Create a generous hole that is big enough to fit the roots and to include aged organic debris at the bottom. Generally speaking, peonies are offered as bare-root tubers, so only choose specimens that are firm and rot-free. With a knife, trim any soft areas. The eyes (small, reddish buds) of the tuber should be one to two inches below the soil’s surface when it is inserted into the hole that has been created. A plant won’t bloom if it is planted too deeply.
Refill and thoroughly irrigate. To keep weeds at bay and maintain moisture, a thin layer of mulch may be used.
With 4 to 5 inches of soil covering the graft, plant a tree peony tuber. The ridge on the stem and a variation in the bark’s texture help identify the graft. The graft can grow its own root system when it is planted deeply.
Maintenance and Care The procedure known as “disbudding” is advised in order to grow bigger flowers. Each stem tip’s terminal bud is kept, but all side buds are cut off. As soon as the buds are apparent, this should be done.
Flowering in subsequent years may be reduced if you cut flowers for indoor enjoyment. As much foliage as possible should be left on the plant and no more than one-third to one-half of the blooms should be cut for cutting.
Care after Bloom By cutting the stem down to a set of leaves within the foliage so that bare twigs are not jutting out, faded blossoms can be removed to stop the generation of seeds. Once a heavy frost has damaged the peony leaf, reduce it to 3 leaves. Tree peonies should not be pruned.
To get rid of diseases that may overwinter in them, remove any mulch that was used during the growing season as well as any fallen leaf. Only first-year plantings need to be mulched over the winter.
Lessening of Flower Production Peonies can grow for many years without being disturbed. When flower production declines, there is typically congestion and a need for division. To reveal the eyes, carefully lift the clump and remove the dirt. Divide the clump into parts, each with three to five eyes and sound roots, using a clean, pointed instrument. Replant right away.
Any of the following reasons could be the cause of a plant’s failure to bloom:
- digging too deep
- undeveloped plants
- more nitrogen encourages the development of leaves
- a lack of potassium or phosphorus
- insufficient sunlight
- overpopulation
- issues with insects or diseases
- competition from neighbouring plants’ roots
- drought
- final freezes
A few species of fungus in the genus Botrytis are responsible for botrytis blight, often known as gray mold. Our entire region is home to these fungus, and cool, rainy weather is ideal for plant infection. Young shoots and flower buds may die, along with blighted leaves or flowers, as symptoms. During humid conditions, affected plant portions will be covered in a brownish mass of spores that appear “fuzzy.” Symptoms of botrytis stem Photo by Bugwood
Spores are carried by the wind or splashed by rain to new infection sites. Sanitation, moisture control, and fungicides are examples of control methods for this and other fungal infections affecting above-ground plant sections. At the end of the season, a thorough clean-up of detritus is included in sanitation, along with the removal of badly infected plant sections or entire plants. Reduced leaf moisture and humidity lessen the likelihood that spores will germinate and infect the plant. If used, water early in the morning and stay away from overhead irrigation. Plants should be placed apart to promote optimum airflow between them. If necessary, use a fungicide with the right label to protect plants before wet weather. For home growers, there are biological, biorational, and conventional choices accessible.
leaf stains On peonies, spots or blotches on the leaves can occasionally be caused by a number of fungi and a bacterial pathogen. All of these diseases are carried by raindrops or irrigation water, so moisture control measures, such as not working among the plants when they are wet, would assist lessen transmission. The majority of the time, spots that take up 30% or less of the leaf surface area will not have an impact on the health of the plant. At the end of the season, thoroughly remove any sick waste; do not put it to your compost pile. A precise diagnosis would aid in the choice of products if the issue seemed severe enough to call for the usage of control products. This is due to the fact that not all fungicides will work against bacterial illnesses. Choosing a product with labels for both pathogen groups is one option.
Botrytis blight The water mold Phytophthora cactorum, which causes Phytophthora blight, can be a problem if peonies are planted in a soil that doesn’t drain well. Dark and leathery tissue is a hallmark of infections by this soil-borne pathogen at the soil line; subsequently, the plant or stem may wilt and die. The roots may also be impacted by disease. Spores can spread infection to portions of above-ground plants if they are splashed on them. The only remedy after an infection is plant removal. Don’t plant in areas with poor drainage.
Powdery mildew is a prevalent issue that can affect peonies. The offending fungus is called Erisyphe polygoni. Over the past few years, peony have seen an increase in powdery mildew occurrence. This disease, which is characterized by a white fungal growth or coating on leaf surfaces, is ugly, although it normally has little impact on the plant’s health. As a result, no control products are typically needed. By growing in full sun and spreading plants to allow for air flow that reduces humidity, illness can be avoided.
On peonies, two fungus, usually found close to the soil line, can cause stem rot. Both southern blight (Sclerotium rolfsii) and white mold (Sclerotinia sclerotiorum) cause stem wilt and death in their victims. Both can result in a white fungal growth that is apparent in damp situations along the soil line or on affected plant sections. Black sclerotia, which are microscopic, rigid fungal resting structures, are generated within dead stems in white mold. Tan to reddish brown sclerotia develop on surfaces in southern blight. Sclerotia can endure for many years in soil. Furthermore, the host ranges of each of these fungi are extensive. Choose non-host plants to replace the diseased ones. Fungicides are normally not advised for use in landscapes.
Versicolor Wilt Verticillium wilt, which is brought on by the fungus Verticillium albo-atrum and V. dahlia, affects peonies as hosts. These soil-borne fungi attack the plant’s roots to cause infection. As soon as they get into the plant, the xylem begins to grow (conducting tissue for water and nutrients). As a result of the infection and the plants’ reaction, the xylem plugs up, obstructing the flow of nutrients and water. Wilt, a lack of nutrients, and poor development are the results of this. By cutting a problematic stem lengthwise, you can check for Verticillium wilt by looking for brown streaks of deterioration. Plants that are infected should be removed and replaced with non-host plants.
Numerous viruses have the ability to infect peonies. Dwarfing, unusual growth patterns, or recognizable yellow mottling, mosaic, or ring patterns on the leaves may all be symptoms. Viruses are transferred mechanically by sap flowing from one leaf to another or by vectors (insects and others) (i.e. when they rub together). No action is required if growth and plant vigor don’t appear to be affected. Plants that aren’t doing well should be pulled out and thrown away.
Ants frequently visit the peony flower buds, but this does not guarantee that scales are present. They are drawn to extrafloral nectar, sugary drops on the outside of the buds, or the honeydew secreted by scale insects, neither of which hurt the plant.
Pathogens that resemble microscopic worms called foliar nematodes feed on the leaf tissue. When leaf surfaces are wet, they travel between feeding locations and enter and exit the leaves through the stomates (pores). Vein-delimited patches of discolouration and dead tissue result from the restriction of their movement within the leaf by the veins. The use of insecticidal washing products and keeping leaves as dry as possible are some control techniques. Infested leaves should also be removed.
On the plant, scale scale insects appear as small raised bumps. During the early stages of growth, these insects choose a fixed feeding location and obtain their food by sucking or piercing plant cells to remove the sap. Plants can get weakened by large populations. Some also generate honeydew, a transparent feces with a lot of sugar. Ants that consume the honeydew find this to be appealing.
Thrips Thrips are tiny, slender insects that may pierce and sucking mouthparts harm buds and plants. Some viruses can be spread via them. Thrips can be controlled with insecticidal soap, but extensive covering of leaf undersides and crevices is required because these treatments must coat the pest in order to be effective. Many thrips might be eliminated by a powerful water spray. Additionally, a variety of naturally occurring predators aid in controlling population growth. Use insecticides only when absolutely essential and never during bloom to safeguard pollinators in order to preserve these beneficials.
For more information, go to the UConn Home & Garden Fact Sheet Insecticides: Low Toxicity Options.
The UConn Plant Diagnostic Laboratory accepts samples of insects or damaged plants for identification or diagnosis.
Even with sound cultural measures, pests and illnesses occasionally do develop. Use of chemical control should only be considered as a last resort.
When should peony be planted?
The peony has the fattest, most delicious petals and rich green foliage, making it outrageously attractive when it is in bloom. From spring to summer, savor stunning floral displays. Learn how to care for, grow, and plant peony.
About Peonies
Peonies are a perennial that will steal your breath away every year. The plants may even outlive you—some have been reported to survive for at least a century.
When Is Peony Season? When Do Peonies Bloom?
Depending on your location and the kind you are planting, peonies bloom from late spring to early summer.
You may extend the peony season across several weeks and take use of those magnificent blossoms for as long as possible thanks to the abundance of nurseries that provide early, midseason, and late blooming types.
Peonies may thrive as far south as Zones 7 and 8, and they are hardy to Zone 3. The key to success in the majority of the United States is to provide full light and well-drained soil. Peonies even enjoy the winter’s coldness because it helps their buds grow.
Types of Peony Flowers
You can pick from six different varieties of peony flowers: anemone, single, Japanese, semi-double, double, and bomb. The odors of different plants also differ; some, like “Festiva Maxima” and “Duchesse de Nemours,” have seductive rose-like aromas, while others have a lemony scent or none at all.
Where to Plant Peonies
When planted as a low hedge or along sidewalks, peonies make excellent sentinels. As majestic and dignified as any flowering shrub, the peony’s bushy cluster of attractive glossy green leaves lasts all summer before turning purplish-red or gold in the fall.
Peonies work nicely with irises and roses in mixed borders and blossom alongside columbines, baptisias, and veronicas. Plant pink peonies with blue Nepeta or violets, then surround white peonies with yellow irises and a froth of forget-me-nots.
Peonies are not overly picky, but you should pick your place carefully because they dislike disruption and do not transplant well.
Although they can survive in partial shade, peonies like full sun, and they flower at their best in an area that receives 6 to 8 hours of sunlight per day.
Because of its huge flowers, peonies can become top-heavy in severe winds. Therefore, provide shelter. (If necessary, stakes can be used to hold them up.) Planting too close to trees or bushes will cause peony to compete with them for nutrients, sunlight, and moisture.
Grow peony in rich, wet, humus-rich soil that is deep, fertile, and well-draining. pH in the soil should be neutral.
When to Plant Peonies
As long as they are planted correctly and become established, peony plants require minimal upkeep. However, keep in mind that they do not adapt well to transplanting, so you should consider this when choosing your planting location.
- Plant peony in the fall: in the majority of the United States, in late September or early October, and even later in the fall in Zones 7 and 8. Your planting zone can be found here.
- If you need to move an established plant, the fall is the ideal season because the plant will be dormant.
- About six weeks before the ground freezes, peonies should be planted.
- While planting peonies in the spring is absolutely a possibility, the results aren’t always favorable. They often trail behind plants planted in the fall by roughly a year, according to experts.
How to Plant Peonies
- Peonies are typically offered as divisions of a 3- or 4-year-old plant, bare-root tubers with 3 to 5 eyes (buds).
- Peonies should be placed 3 to 4 feet apart to allow for enough air circulation. The development of disease can be facilitated by stagnant, damp air.
- In a sunny area, dig a generously sized hole that is about 2 feet deep and 2 feet wide. The inclusion of organic matter in the planting hole will improve the soil. Add additional compost to the soil to improve it if it’s sandy or heavy. Add about a cup of bonemeal to the ground. Find out more about soil improvements and getting the soil ready for planting.
- The roots should be positioned in the hole just 2 inches below the soil’s surface, with the root’s eyes facing upward on top of a mound of soil. Avoid planting too deeply! Choose early-blooming species, put them approximately 1 inch deep, and provide some shade in southern states.
- Backfill the hole after that, being careful to prevent soil settlement and a 2-inch root burying. Gently tamp the ground.
- Plant a container-grown peony no deeper than it was when it was in the pot.
- When planting, give everything plenty of water.
How to Care for Peonies
Young peony take time to develop, just like children. In order to establish themselves, blossom, and flourish, they typically require a few years. They eventually leave home on their own, fully grown and adjusted… No, that’s just kids, I suppose.
Peonies benefit from gentle neglect. They don’t require digging and dividing every few years like the majority of perennials do.
- Don’t use any fertilizer. Before planting, till the soil thoroughly while adding compost and a small amount of fertilizer.
- Early summer, after the peonies have flowered and you have deadheaded the blooms, is the ideal time to apply fertilizer (such as bonemeal, compost, or well-rotted manure) to a soil that is deficient in nutrients. Keep fertilizing to a few years at most.
- assist the stems Peonies’ stems, which occasionally are not strong enough to hold their enormous blossoms, are the only part of their structure that may be considered weak. Think of structures that allow the plant to grow through the middle of the support, like three-legged metal peony rings or wire tomato cages.
- Peony blossoms should be deadheaded as soon as they start to fade, cutting to a sturdy leaf so that the stem doesn’t protrude through the foliage. To prevent any infections from overwintering, trim the foliage to the ground in the fall.
- Avoid covering peonies with mulch. For the first winter following planting, you can VERY LOOSELY mulch with pine needles or shredded bark when the winters are bitterly cold. In the spring, get rid of the mulch.
Peonies bloom between late spring and early summer, but by planting a variety of cultivars, you may arrange your garden for a succession of blooms from mid-May to late June. Here are a few options:
- ‘Early Scout’ has red solitary flowers that open incredibly early.
- “Firelight”: very early-blooming, single, pale-pink flowers
- ‘Karl Rosenfield’: double, midseason bloomer with substantial crimson blooms