Tree Peony Design, planting, and Care

Tree Peonies are woody perennial shrubs. They bloom in early spring, after woodland peonies and before herbaceous peonies. Their woody structure supports gigantic dinner-plate-sized flowers on plants that can grow up to 7 feet. While tree peonies can take full sun, they thrive in dappled light. After the bloom, tree peonies provide structure to the garden, with deep green foliage in summer that turns bronze and purple in fall. Native to China and cultivated for millennia, these deer-resistant plants thrive in zones 4-9. Some die-back may occur in zone 4 during particularly harsh winters. Tree peonies grow slowly, producing 1 to 6 inches of new woody growth each year. They require well-drained soil. A plant for the landscape. Stately, rare, breathtaking flowers, simply fabulous.

Looking for information on other types of peonies: Intersectional Peony Care | Intersectional Peony Care | Woodland Peony Care

New tree peony plants should be planted 5 feet apart on center, and approximately 2.5 feet from any edge or border. Once you have determined the site, measure the space you have available. If you are planting one plant, then your calculations are simple; if you are designing a larger garden, scroll down for our recommendations.

Think long-term when you are laying out your peony garden; tree peonies will take about ten years to mature, and will live happily with minimal care for decades.

Be wary of planting in areas where snow can fall from roof lines and where snow gets piled by shovels or plows. If your tree peony is planted in such areas, precautions should be taken to prevent the branches from breaking.

Tips for Fall

Fall planting occurs from late August until the ground freezes solid for winter.

As with all cold-hardy plants, fall is the traditional time to plant and historically the only time peony roots were available. Thus, typically peonies are shipped bare root in the fall. They are freshly dug, and should be planted immediately.

PEONIES ARE COLD-HARDY PERENNIALS. They should be planted the first chance you can get a shovel in the ground, regardless of frost or freeze potential. Do not wait for the frost date to plant your peony roots.

PLANT THEM AS SOON AS POSSIBLE. Utilize the day or so between cold periods, when the ground is thawed enough to dig. New peonies are susceptible to frost heaving; any peonies heaved out of the ground should be put back to their original location. If it is too frozen to do so, they can be covered in place with soil until the ground thaws or taken in and placed in peat moss in the refrigerator until the ground thaws enough to dig. Do not mulch your peonies; they need the cold to flower in the spring, and mulch will insulate peonies from the cold.

Tips for Winter

Winter planting occurs from the time the ground freezes solid, until the time the ground starts to thaw.

Follow the same instructions for winter planting as you would for fall planting. Here are some additional tips for the winter months:

IF THE GROUND IS FROZEN SOLID at the time of purchase or delivery, it is best to store your peony roots in the fridge until you are ready to plant. Keep them in the bag as they came, do not add water.

PEONIES ARE COLD-HARDY PERENNIALS. Plant them the first day that the ground has thawed enough to get a shovel in the ground. Do not worry if the ground has the potential to freeze again, or if it will snow.

IF YOUR PEONIES HAVE SPROUTED, plant as above. Make sure to protect new shoots from frost, as they are more susceptible to frost damage if not planted the correct distance underground.

Tips for Spring

Spring planting occurs from the time the ground starts to thaw, through mid June.

PEONIES ARE COLD-HARDY PERENNIALS. They should be planted the first chance you can get a shovel in the ground, regardless of frost or freeze potential. Do not wait for the frost date to plant your peony roots. It is best to plant them while you still have cold or snowy days in the forecast.

IF THE GROUND IS FROZEN SOLID at the time of purchase or delivery, it is best to store your peony roots in the fridge. Plant them the first day that the ground is soft enough to dig, regardless of future temperatures. Keep them in the bag as they came, do not add water.

If you are planting bare-root peonies in spring, it is likely that your peonies will produce minimal growth above ground the first year. If you are planting peonies that have been grown in pots, there is potential that the buds will wither and the leaves will die back early. Don’t worry, this is normal. That said, diseases are more prevalent on peonies that have been planted in spring. Watch for botrytis and treat accordingly.

There is an old adage when planting perennials: "First year roots, second year shoots, third year flowers." Getting your peonies in in the spring gets a jump on things, giving your plant a good first spring of root development. Next year you are likely to have a reasonably sized peony with the potential of a flower or two.

Dig Your Hole

New tree peony plants should be planted 5 feet apart on center, and approximately 2.5 feet from any edge.

Start by digging a hole at least 2 feet deep and 1 foot wide. This will seem like a huge hole, but it is necessary for root growth and drainage. Your tree peony prefers to be planted and left in one location for generations, so it is worth taking the time to do it right. Amend your soil, as mentioned below.

Tree peonies should be planted deeply.

Grafted tree peonies should be planted so that the graft is six inches below the surface of the soil. This deep planting allows the tree peony to grow its own root system and prevents the grafted herbaceous root from growing herbaceous shoots. Any herbaceous shoots growing from a grafted tree peony should be cut back, and planting depth should be checked.

Tree peonies growing from their own root system should be planted so that the point at which the stems emerge from the root is two inches below the surface of the soil. This will promote additional branches to emerge from the root.

Once planted, press down on the soil to remove air pockets around the root and water your tree peony in well. During the first two growing seasons after planting a new tree peony, ensure that it gets a good soaking every two weeks. This will allow the plant to get enough water while the root system becomes established. Remember that peonies do not like wet feet and be careful to not over water. The soil needs to dry out fully between waterings. Watering daily or the use of foliar sprinkler systems can cause rot. It is essential that your peony be planted in well-draining soil so that the water does not pool around the plant. Established peonies are incredibly low maintenance and require little to no supplemental watering, except in times of extreme drought.

Amend the Soil

Peonies in Pots

We do not recommend planting peonies in pots, especially tree peonies. They do best when planted in the ground. Peonies are long-term perennials that will live for generations.

If you don’t have any space directly in the ground peonies can be successfully grown in raised beds. Drainage is the key to planting in any situation, especially raised beds. The beds need to be at least 2 feet deep to accommodate the deep planting necessary for tree peonies, see above. We line the boxes with landscape fabric and fill them with potting soil amended with compost, worm castings, and crushed limestone or granite. The beds are placed on the existing soil for optimal drainage.

If you have lots of experience growing other long term perennials in pots you may also have success with peonies but it is risky. Make sure your pot is large, more like a planter, is at least 2 feet deep and at least 5 gallons in size - the bigger the pot the better. Commercial potting mixes are available, we have yet to find one that we really like, look for those with extra porosity.

Containers will need to remain outside in the winter as peonies need the cold season to flower (do not bring them inside or store in a warm greenhouse). Be sure that your pots do not continually fill with water, as this will cause peonies to rot. Peonies are especially susceptible in winter when the bottom of the pot can be frozen and prohibit drainage if the weather switches to rain. This factor is easier to mitigate in warmer climates that get fewer extreme freeze thaw cycles.

We also do not recommend having peonies in pots for a few seasons and then moving them to the ground. Peonies should be planted originally in their permanent location. Moving them will cause undue stress to the plant.

The graphics below show growth expectations for tree peonies.

It is possible that a tree peony will not produce growth above ground or leaf out the first spring. This can be very scary but typically the tee peony will start to take off the following spring. Even it they do leaf out the first year, do not expect much out of your tree peony. Peonies are very resilient and hardy, but do take time to establish and become a mature flowering plant.

They follow the adage, ‘first year roots, second year shoots, third year flowers’.

Tree peonies should reach full height and size by year ten. The height, leaf coverage, and flower posture of your tree peony depends on the cultivar.

To choose the best cultivars for your particular garden, it is good to know more about the history and hybridization of each peony plant. This greatly influences how each cultivar behaves in the garden. These factors will also influence the bloom time. The main groups of tree peonies are, in order of bloom:

• Classic Tree peonies (Suffruticosa)

• Gansu Tree Peonies (AKA Rockii)

• Yellow Tree Peonies (Lutea hybrids),

We will review the characteristics of each type below, with suggestions on how to choose cultivars. We will start with the largest group, the classic tree peonies.

Using Classic Tree Peonies (Suffruticosa)

First to bloom is the Suffruticosa group of tree peonies. Originating from the Central Plains of China, Suffruticosa is one of the largest and most genetically-diverse classifications of tree peonies. Colors bloom in all varieties of magenta, from white and pink to a deep maroon (yellows, oranges, and true reds are absent from this group). Though the chrysanthemum form dominates, flower form ranges from single to bomb. The leaves range in shape from medium to round/orbicular, and they vary tremendously in leaf color. Fragrance dominates in this group.

Plant Shape

Typically, a ten-year-old tree peony will measure 5 feet tall and 5 feet wide. Vertical growth and spread develops at the same rate. That said, the shape of the plant is determined by the individual cultivar. Tree peonies are broken up into three major shapes:

• Tall/Conical

• Medium/Part Spreading

• Dwarf/Spreading.

They grow slowly and take 10+ years to reach full size. Taller varieties tend to grow a bit faster than dwarf varieties. Three to four inches of growth each year is common. As a general rule, plant tree peonies 5' apart and give them plenty of time to mature. Tree peonies planted in cold climates will experience slight to significant die back, depending on the conditions and the cultivar, and should not be expected to reach their full height or spread.

Flower Posture

Generally, tree peony flowers are upright, with flowers blooming above the leaves of the plant. Sometimes, the flowers present laterally, with the flowers being at the edge of the leaves. Occasionally, as with some Lutea yellow and orange hybrids, flowers will be pendulous. Upright flowers are carried at the ends of stiff stems, well above the leaves, and grow at the top and sides of the bushes. Pendulous flowers have short, flexible stems and hang down under the leaves.

Bloom Time

The bloom times listed in our catalog are relative to other tree peonies. All tree peonies will bloom within a 3 week window. Each individual plat will bloom for 5-10 days within that period. The timing of this period is based on your location. Here in NJ our tree peony bloom is typically from around May 1 to May 20. South of here will have an earlier bloom, north will have a later bloom.

• The suffruticosa group typically blooms before the Gansu group, which blooms before the Yellow Lutea group.

Flower Color

The Suffruticosa group is responsible for every color listed below except yellow, copper and coral. Those come from the Lutea group.

Leaf Shape

Tree peony leaves provide beauty in the garden for three seasons. They leaf-out in early in April and provide spring, summer, and fall color. The size of the leaf varies from long and thin to big and round. Most of the Suffruticosa peonies have either Medium or Round leaves, while all of the Gansu have Long Thin leaves.

The Gansu group of tree peonies is a subset of the Suffruticosa group, distinguished by a purple flare at the center of each flower petal. Originally from the Gansu region of China, these plants are also referred to as Rockii peonies, as Joseph Rock helped make them famous outside of China. These plants are fast-growing for tree peonies, exceptionally hardy, and grow up to 7 feet tall. This group has thin billowy leaves that give a more informal appearance. They tend to cross-pollinate and produce wonderful seeds that can be grown into new cultivars. Peony’s Envy boasts a large collection of Gansu tree peonies.

Last of the tree peonies to bloom is the Lutea group, often overlapping with the bloom period of herbaceous peonies. Sometimes referred to as Delavayi, this group is a Tibetan species that has a wide variety of yellows, bronzes, and oranges.

Of special note is that lutea hybrids are the main tree peony group that has been used to create intersectional peony hybrids-intersectional peonies have inherited the wonderful colors of the lutea hybrids.

Tree peonies can tolerate more heat than herbaceous peonies and can grow all the way south to Horticultural Zone 9! No additional care is recommended or required for these types of peonies in zones 7 through 9.

Feed Peonies

Planted in full to half-day sun with rich soil and great drainage, tree peonies can thrive almost entirely on their own as the nutrient cycle is self-sustaining. Nonetheless, a little food will help keep your peonies healthy and floriferous.

Feed lightly three times a year—in the fall when you clean up your garden and prepare plants for winter, in early spring just as shoots emerge, and again in early summer after plants have bloomed.

Compost: At Peony’s Envy, we primarily use locally-sourced compost, Neptune’s Harvest Fish and Seaweed Emulsion, and OMRI-certified worm castings. When applying compost, thin layers are better than thick, and remember to apply at the drip line and not over the center of the plant, since applying on the root will bury the plant too deeply and eventually prevent flowering. For large-scale projects in the area, we recommend Full Circle Mushroom Compost.

Foliar Feeds: Plants absorb nutrients more efficiently through their leaf surfaces than through their roots. Liquid fertilizers, such as Neptune's Harvest Fish and Seaweed Fertilizer or Nature’s Source plant food, can be used to foliar feed during critical growing times. We recommend foliar feeding in early spring when peonies are setting buds.

Worm castings: When first planting, when planting in pots, or to reinvigorate a garden after long-term neglect, we recommend using worm castings as an extra boost. It is garden gold, and a little goes a long way. As an added bonus, peonies will love its high pH.

If you choose to use synthetic or partially synthetic fertilizers, choose one that is well-balanced and releases nutrients at a slow rate. A 10-10-10 fertilizer is best for spring and summer, and a 5-10-10 is best for fall. Rarely do we use synthetic fertilizers at Peony’s Envy.

Deadheading Peonies

After the bloom, unless you are interested in collecting peony seeds, deadhead your peonies to promote root growth over seed formation. Cut the stem just below the spent flower. Removing excess stem will reduce the amount of growth in the following year and should be avoided. This year’s green shoots will become next year’s woody branch.

Watering Peonies

With the more frequent droughts we have adjusted our tips on watering. Peonies like heavy infrequent soakings; when irrigation is necessary, consider drip lines instead of overhead sprinkler systems. During the first growing season after planting a new peony, ensure it gets a good soaking once a week. Weekly soakings keep the plant from being stressed by drought as it develops its fibrous root system. However, remember that peonies do not like wet feet, and be careful to not over water. Watering daily or use of foliar sprinkler systems can cause rot. It is essential that your peony be planted in well-draining soil so that the water does not pool around the plant. Established peonies require less supplemental watering but still benefit from heavy infrequent soakings, especially in times of drought.

Weeding/Mulching - Do Not Use Wood Chips or Weed Suppressants

Unlike herbaceous peonies, tree peonies can be mulched. Avoid any mulch with wood chips or bark, as this promotes artillery fungus growth. Remember that light layers of compost applied regularly around the drip line of your peonies (again, not on the crown) will feed your garden and can also help suppress weeds.

Weed around your peonies. The shade from mature peonies will act as a weed suppressant from late spring to late fall. The first application of compost in early spring helps combat weed growth. After applying this first thin layer of compost, remove any weeds before they seed—this will ensure they do not spread throughout the year.

We often recommend under-planting your peonies with small spring bulbs, like miniature daffodils and crocus. They bloom before peonies, don't compete with them, and provide a nice early summer groundcover that reduces weeds. Be careful not to plant anything larger or that is particularly invasive around your peonies, or anything that will compete with your peonies and cause them to suffer. This is especially important for tree peonies that should be planted in one location and not disturbed.

Do not use any pesticides or weed suppressants anywhere close to your peonies! We have had several customers contact us with dead plants only to find out after laboratory testing that the runoff from their lawns, that had been sprayed with weed suppressants, killed their plants.

Dead branches and any diseased portions should be removed spring and fall to promote the overall health of the plant. Otherwise, tree peonies do not need to be pruned.

Like all woody perennials, tree peonies can become leggy over time. If you wish to prune your mature tree peony for shape, this is best done over a few seasons. Plants can be trimmed in the spring and/or fall. Spring pruning will remove leaves and limit the ability of the plant to photosynthesize. Fall pruning will trim off next year’s flowers-buds are set in the spring right after the flowers fade. It is good to do a bit of trimming in both seasons to limit the impact. Spring pruning should be done early, as the plant begins to bud out. Fall pruning should be done just as the plant begins to go dormant.

If you are wanting to prune a large portion off your tree peony, know that you should never remove more than a third of the woody portion of the plant in one season. This is common practice with perennials, as taking more than a third of the plant puts too much stress on the plant and can cause it to die. It is best to be patient and take only a portion of what you are wanting to take the first year, and prune it to the shape you desire in the coming years. Prune branches at an angle, just above a leaf node, to promote branching

If you are experiencing heavy die back on your tree peony, and you are not in zone 4, this could be a sign of a fungus or insect problem. We recommend sending branches to an agricultural extension to determine the exact cause. We use Rutgers.

We have customers ask us what they can do with the portions of the tree peony they cut off. Unfortunately, you cannot stick the end of the stem in rooting hormone and expect it to grow a tree peony. However, you can graft the tree peony to an herbaceous nurse root. See our grafting section for details.

Tree peonies are very cold tolerant. Notice in the image above where the leaves in the forest have all but dropped and yet the tree peonies are still holding their leaves. Once the leaves begin to color and naturally fall, winter preparation consists of carefully removing any remaining old leaves and cleaning all leaves from the base of the stem. Tree peonies should not be cut back! Pruning can be done for shape, but this is best done in the spring right after the plants have flowered. See pruning section directly below for details. When removing the leaves in the fall snap them off with your hand, as indicated in the picture below, leaving the new buds on the branches intact. Those new buds will form next year’s woody growth and flowers. If the leaves do not snap off easily, cut them off close to the stem. All the leaves should be thrown away-your backyard compost pile does not hot enough to kill the spores and bacteria that may be on the plant.

Tree peonies can have flowers as large as dinner plates. Stems should be cut short, less than two inches, to avoid cutting off what will become next year's woody stem and flowers. They can be floated in large glass vases and bowls, making an incredible statement on any table.

Peonies are very resilient plants that typically thrive and grow without incident. However, every once in a while a fungus or virus may take hold and impact the health of your peony plants. Although infections generally start in early spring, they often go unnoticed until later in the summer. Left unchecked, these diseases can do real damage to your peonies.

Powdery Mildew - Erysiphales (Fungus)

If you are experiencing a white powder like covering on the leaves of your peony, you have powdery mildew in your garden.

SYMPTOMS: Leaves turn white. Onset is in late June through September. It is not fatal and tree peonies are less prone than herbaceous or intersectional peonies to this fungus. In some years, powdery mildew is worse than others. It can infect plants when there are hot days, high humidity, and cool nights. Once the plant is infected there are virtually no sprays or oils that will completely rid the plant of powdery mildew this year. However, there are some preventative remedies to keep your plants from getting powdery mildew in coming years.

TESTING: We encourage you to get your plants tested so you know exactly what you are dealing with. Send a sample to your State’s Agricultural University ‘s Plant Diagnostic Center for laboratory diagnosis and treatment recommendations. At Peony’s Envy we use both the Plant Diagnostic Laboratory of Rutgers NJAES and the Cornell Plant Disease Diagnostic Clinic.

OUTLOOK: Considered more unsightly than harmful in peonies.

TREATMENT: Bacillus subtilis to boost plant's natural defenses; neem oil or other horticultural oils after the leaves have formed; baking soda spray (1t baking soda, 1qt. water and a few drops of liquid soap) on the soil in early spring and on the plant itself in the summer; rhubarb leaf tea; cornmeal as a soil amendment; or mixed as a spray; products containing sulfur, or a biofungicide recommended to treat powdery mildew on peonies;. All pesticides should be used according to package directions, and remedies should be tried on portions of the plant prior to making large scale applications.

Another good natural preventative remedy is to regularly spray a solution of 30% milk to 70% water on your plants on sunny days. This helps not only peonies, but all plants susceptible to powdery mildew. 

PREVENTION: Healthy plants are less susceptible to disease. Peonies require the proper amount of sun, nutritious soil, good air circulation, and the right amount of water. Encourage good air circulation by spacing peonies at least 3 feet apart and by keeping the base of each plant clean and free of weeds. Water only as needed and always in the morning using drip irrigation; do not use overhead irrigation and avoid watering at night. Never plant peonies in low-lying areas where soils flood. Amend soils prior to planting to ensure good drainage and proper nutrition. Use compost to maintain nutritious soil. Keep a close eye on your peony plants especially during early spring rains when fungi and viruses begin to take hold.

Botrytis - Botrytis paeoniae (Fungus)

SYMPTOMS: Stalks wilt and die, buds turn black. Onset is typically in early spring but can be at any time when temperatures remain below 70 degrees. Botrytis is especially prevalent when the weather is cool, wet, and humid. Botrytis is common and when seen in your garden can persist for years through spores in the soil.

TESTING: We encourage you to get your plants tested so you know exactly what you are dealing with. Send a sample to your State’s Agricultural University ‘s Plant Diagnostic Center for laboratory diagnosis and treatment recommendations. At Peony’s Envy we use both the Plant Diagnostic Laboratory of Rutgers NJAES and the Cornell Plant Disease Diagnostic Clinic.

OUTLOOK: Botrytis is easy to treat but can kill peonies and other plants when not treated, so it is especially important to pay attention to signs of the fungus.

TREATMENT: When noticed, cut off diseased portions of the plant, dipping the pruners in a 10% solution of bleach (or use Clorox wipes) between each cut to ensure the disease does not spread. Throw out the diseased portions; do not compost. A more aggressive option would be to use systemic fungicide labeled for use on peonies. The cooperative extension service of New Jersey recommends Ferban and Manebrom. Griffin Greenhouse Supply recommends products including Cease, Daconil, Medallion, and Veranda-O. Follow label instructions carefully and test fungicides on one plant before making large scale applications. Continue to treat according to the label instructions as the disease persists. Their are OMRI approved fungicides for the treatment of botrytis.

PREVENTION: Healthy plants are less susceptible to disease. Peonies require the proper amount of sun, nutritious soil, good air circulation, and the right amount of water. Encourage good air circulation by spacing peonies at least 3 feet apart and by keeping the base of each plant clean and free of weeds. Water only as needed and always in the morning using drip irrigation; do not use overhead irrigation and avoid watering at night. Never plant peonies in low-lying areas where soils flood. Amend soils prior to planting to ensure good drainage and proper nutrition. Use compost to maintain nutritious soil. Keep a close eye on your peony plants especially during early spring rains when fungi and viruses begin to take hold.

Peony Blotch/Red Spot/Measles - Cladosporium paeoniae (Fungus)

SYMPTOMS: Small circular round spots begin to appear in spring just before the plants flower. The spots will increase in size and are not often detected until mid summer. If left unchecked spots can eventually cover the whole plant.

TESTING: We encourage you to get your plants tested so you know exactly what you are dealing with. Send a sample to your State’s Agricultural University ‘s Plant Diagnostic Center for laboratory diagnosis and treatment recommendations. At Peony’s Envy we use both the Plant Diagnostic Laboratory of Rutgers NJAES and the Cornell Plant Disease Diagnostic Clinic.

OUTLOOK: Does not immediately kill the plant but successive years of the fungal disease will impact the health of the plant.

TREATMENT: When noticed, cut off diseased portions of the plant, dipping the pruners in a 10% solution of bleach (or use Clorox wipes) between each cut to ensure the disease does not spread. Clean up all debris around the plants, and throw all of this matter away - do not compost. Use a fungicide that is intended for Peony Blotch on peonies, apply according to the manufacturers instructions.

PREVENTION: Healthy plants are less susceptible to disease. Peonies require the proper amount of sun, nutritious soil, good air circulation, and the right amount of water. Encourage good air circulation by spacing peonies at least 3 feet apart and by keeping the base of each plant clean and free of weeds. Water only as needed and always in the morning using drip irrigation; do not use overhead irrigation and avoid watering at night. Never plant peonies in low-lying areas where soils flood. Amend soils prior to planting to ensure good drainage and proper nutrition. Use compost to maintain nutritious soil. Keep a close eye on your peony plants especially during early spring rains when fungi and viruses begin to take hold.

Phytophthora Blight - Phytophthora cactorum (Fungus)

SYMPTOMS: Phytophthora blight is a soil-borne fungus. The stems at the base of the plant will begin to darken and then wilt and die. Leaves may appear drought stressed. The entire plant may rot making it easy to pull from the ground. The fungus can survive in the soil for years as long as moist conditions persist. Can be spread by garden tools and contaminated soil. Symptoms are often more evident during periods of low rainfall making it easy to confuse the onset of this disease with drought.

TESTING: We encourage you to get your plants tested so you know exactly what you are dealing with. Send a sample to your State’s Agricultural University ‘s Plant Diagnostic Center for laboratory diagnosis and treatment recommendations. At Peony’s Envy we use both the Plant Diagnostic Laboratory of Rutgers NJAES and the Cornell Plant Disease Diagnostic Clinic.

OUTLOOK: Phytophthora can kill peonies and other plants.

TREATMENT: When noticed, cut off diseased portions of the plant, dipping the pruners in a 10% solution of bleach (or use Clorox wipes) between each cut to ensure the disease does not spread. Clean up all debris around the plants, and throw all of this matter away - do not compost. Rutgers Diagnostic Lab notes that the fungicide Subdue can be used to treat Phytophthora on peonies, apply according to the manufacturers instructions. Be sure to treat both the plant and the soil. Improve soil drainage and prevent water from pooling near plants.

PREVENTION: Healthy plants are less susceptible to disease. Peonies require the proper amount of sun, nutritious soil, good air circulation, and the right amount of water. Encourage good air circulation by spacing peonies at least 3 feet apart and by keeping the base of each plant clean and free of weeds. Water only as needed and always in the morning using drip irrigation; do not use overhead irrigation and avoid watering at night. Never plant peonies in low-lying areas where soils flood. Amend soils prior to planting to ensure good drainage and proper nutrition. Use compost to maintain nutritious soil. Keep a close eye on your peony plants especially during early spring rains when fungi and viruses begin to take hold.

Sclerotinia Rot/Southern Blight (Fungus)

SYMPTOMS: Sclerotinia Rot is a soil-borne fungus.Rot begins at the base of the plant with water-soaked stem lesions. Leaves will turn yellow and die. During times of high humidity a white cotton-like fungus spreads around the base of the plant and the soil. The fungal fruiting bodies appear like small collections of mustard seeds on the ground near the base of the plant.They may eventually form a crust on the soil.

TESTING: We encourage you to get your plants tested so you know exactly what you are dealing with. Send a sample to your State’s Agricultural University ‘s Plant Diagnostic Center for laboratory diagnosis and treatment recommendations. At Peony’s Envy we use both the Plant Diagnostic Laboratory of Rutgers NJAES and the Cornell Plant Disease Diagnostic Clinic.

OUTLOOK: Sclerotina can kill peonies and other plants.

TREATMENT: Rutgers Diagnostic Lab recommends using either Heritage or Headway for use on peonies for Sclerotina Rot, apply according to manufacturers directions. Be sure to treat both the plant and the soil. If that fails, remove diseased plants and the surrounding soil from your garden, do not compost. Sterilize all tools. Cover the area with clear plastic and leave it for two to three months in the heat of summer. After this period, increase the drainage in your soil and leave the soil fallow for at least one season before replanting.

PREVENTION: Healthy plants are less susceptible to disease. Peonies require the proper amount of sun, nutritious soil, good air circulation, and the right amount of water. Encourage good air circulation by spacing peonies at least 3 feet apart and by keeping the base of each plant clean and free of weeds. Water only as needed and always in the morning using drip irrigation; do not use overhead irrigation and avoid watering at night. Never plant peonies in low-lying areas where soils flood. Amend soils prior to planting to ensure good drainage and proper nutrition. Use compost to maintain nutritious soil. Keep a close eye on your peony plants especially during early spring rains when fungi and viruses begin to take hold.

Viral Diseases

Peonies are also susceptible to a small number of viruses including peony ringspot virus, leaf curl, Le Moine disease, and the mosaic virus. These are rare, difficult to cure, and it is generally recommended to remove infected plants from your garden.

SYMPTOMS: Poor growth and stunted growth. Leaves will have a mottled/mosaic appearance. Portions of the leaves can turn yellow and die. Can be spread by insects or tools.

TESTING: We encourage you to get your plants tested so you know exactly what you are dealing with. Send a sample to your State’s Agricultural University ‘s Plant Diagnostic Center for laboratory diagnosis and treatment recommendations. At Peony’s Envy we use both the Plant Diagnostic Laboratory of Rutgers NJAES and the Cornell Plant Disease Diagnostic Clinic.

OUTLOOK: Viral diseases can kill peonies and other plants. Remove and dispose of infected plants, do not compost.

PREVENTION: Healthy plants are less susceptible to disease. Peonies require the proper amount of sun, nutritious soil, good air circulation, and the right amount of water. Encourage good air circulation by spacing peonies at least 3 feet apart and by keeping the base of each plant clean and free of weeds. Water only as needed and always in the morning using drip irrigation; do not use overhead irrigation and avoid watering at night. Never plant peonies in low-lying areas where soils flood. Amend soils prior to planting to ensure good drainage and proper nutrition. Use compost to maintain nutritious soil. Keep a close eye on your peony plants especially during early spring rains when fungi and viruses begin to take hold.

Chafer Beetles

SYMPTOMS: Peony flowers being eaten. Chafer beetles look similar to Japanese beetles. They can be removed by hand or killed with almost any insecticide. Neem oil is an organic option, read the product label for more detailed instructions. Ants are a natural predator and chase away chafer beetles.

Bud-Blast

A wide variety of stressors can prevent peony buds from opening. This can include poor soil, immature plants, plants being buried too deeply, excessive mulch, not enough sun, and early spring frosts. Check the depth of your peony and adjust if necessary.

Tree Peonies Not Blooming

In most cases, if your tree peony is not blooming, it is simply not mature enough to produce flowers. This will self-correct as the plant becomes larger. See our section on growth expectations for images of what to expect of your tree peony. Know that when you do begin to get flowers on a newly planted tree peony, they will be small, about the size of a quarter, and that the flowers will enlarge as the plant matures.

It is uncommon to have mature tree peonies that do not bloom, but if you do you should first check the depth of the plant and make sure that it is buried sufficiently and the roots are not exposed, causing stress on the plant. If you have a very mature tree peony that has begun to bloom less, this could be to surrounding root and sun competition. Over time, surrounding trees and shrubs can shade out your peonies resulting in fewer and fewer flowers. The less sun you have the fewer flowers you will get.

Tree Peony Blooms Twice

If you are getting two sets of blooms on your tree peony, one early and one a few weeks later, you have a grafted tree peony. What is happening is that the herbaceous root stock is flowering after the tree peony branches have flowered. This is something that should be prevented, as it could cause the herbaceous rootstock to flourish at the expense of the tree peony. In this case, you should cut back the herbaceous stems emerging from the base and mulch the plant in deeper to promote the tree peony to form its own roots.

New tree peony branches are multi branched, and should NOT be cut back. Herbaceous shoots emerging from the graft will be single stalks with no branches.

If you are lucky enough to have mature peonies in your garden and they are blooming beautifully, first consider leaving them where they are, as peonies will sulk for a year or two after they are transplanted. If transplanting is inevitable, the time to do this is in the fall when the plants are dormant. If you are in a crunch, peonies can be transplanted successfully at other times of the year, but this is not recommended.

Before you start digging up your peony it is important to prepare the new location as mentioned on our Planting section.

The time to transplant tree peonies is in the fall, when the plants have become dormant. To lift your established tree peony, begin at least eighteen inches from the base of the stem, loosen the plant from the soil with a large garden fork, work your way around the plant, and gently pry it from the ground. The roots will be deep and tough. Have burlap ready to help secure the root ball. Cut off any remaining leaves, being careful not to remove what will become next year’s woody stem. Plant immediately and water in well. Note that when moving a tree peony, it will take several years for it to return to its previous health.

Grafting Tree Peonies

Below is a step by step guide to grafting tree peonies. Note that the type of herbaceous nurse root can influence your outcome. One peony that is particularly well-suited for growing tree peonies is Scarlet O'Hara, a plant we often carry in our online catalog. Here are a few places to buy grafting tools: Fedco Seeds, Orchard Valley Supply, Ben Meadows

If you are interested in propagating peonies from seeds, wait to see if a seedpod begins to form as in the first picture. Seeds will ripen and be ready to plant in early fall. Note that not all peonies can produce seeds, as the stamens have been diminished or lost in the hybridization process. If a peony is not able to produce seeds, the stem will not produce a seedpod. In this case, cut the stem right below the old flower.

Note that to get a peony the same as another you currently grow, you must divide the root or graft the tree peony. If you are lucky enough, however, to have a variety of peony that produces seeds, the seeds will produce peonies distinct from the parent and unique to you.

Plant the seeds one inch below the surface of the soil immediately after the pods open. Plant them outside in similar conditions favored by the mother plants. Mark them well and wait. We often plant our seeds in bulb crates. This helps us keep track of their progress and makes them easy to transplant once they have grown. Below is a photo of tree peony seedlings growing at our nursery.

Expectations: It may take two years for a seeding to emerge, as many as ten years for the plants to produce flowers, and as many as twenty years for the plant to reach full size.