How to Grow and Care for Peonies

Peonies are the spring-blooming stars of your garden with large, showy blooms, heady aromas, and plenty of personality. By some estimates, there are as many as 33 species within the genus Paeonia, known collectively as peonies. Most are herbaceous perennials, though a few are woody shrubs. Peonies are medium-sized with tuberous thick storage roots and thin roots designed to absorb water and nutrients. It's critical to carefully handle the roots when planting, transplanting, or dividing peonies to propagate. Peonies contain the compound paeonol, which is mildly toxic to animals.

Planting and Transplanting Peonies

Peonies are typically purchased as potted plants in ½- or 1-gallon containers at the nursery or as bare roots, often packaged with peat moss or wood shavings in plastic bags. The peonies offered at plant society sales or plant swaps are usually the tuberous bare root varieties.

When choosing potted peonies, look for healthy specimens without leaf spots or weak-looking stems. When planting from bare tuberous roots, ensure the root clump has at least three to five eyes. These eyes will eventually elongate and become the plant's stems. A mature peony should be at least three to four years old before it is divided into bare roots. Tuberous clumps with only one or two eyes may still grow, but they will take longer to become established blooming plants.

When to Plant

Bloom time for peonies varies from late spring to late summer, depending on the variety, but all types are best planted in the fall, about six weeks before the ground freezes. This gives the plant time to settle in and establish roots before winter. This is especially true when planting bare-root peonies or transplanting. Planting potted peonies in the fall also offers better results.

Selecting a Planting Site

Choose a location that is sheltered from strong winds. The large heavy blooms of this plant can cause the stems to flop over during heavy rain and inclement weather. Plant them well away from other trees and shrubs, since they don't like to compete for nutrients and water.

Spacing, Depth, and Support

Give each peony plant enough space to grow to maturity without being crowded. That means a 3- to 4-foot diameter for each plant.

Peonies like a good chill in the winter. Set their flower buds by planting peony roots relatively close to the soil surface—only about 2 inches deep. It may feel odd to leave roots exposed but peonies need this chilling to attain dormancy and set buds.

Your peonies will benefit from some support staking.

Transplanting

If an established peony needs to be moved, transplanting should be done carefully to avoid disturbing the roots any more than necessary. These plants can thrive in the same spot for decades, but moving one hastily can bring about its demise. Fall is the best time to move a peony. Transplanting requires compost or peat moss, a sharp spade, and a tarp. Here's how to transplant a peony plant:

1. At the new planting site, till up the soil 12 to 18 inches deep, and mix in a 4-inch layer of compost or peat moss.
2. Water the peony with 1 inch of water a day or two before transplanting. Your plant must be well-hydrated before moving it.
3. Dig around the root ball of the peony using a sharp spade, getting as much soil as possible. Slide a tarp under the root ball to keep it intact, then lift the plant from the ground and carry or slide it carefully to the new location.
4. At the new location, dig a hole twice as wide as the peony's root ball, and exactly as deep as the root ball. Plant the peony at the same depth as in its old location.
5. Backfill around the plant. Tamp the soil down with your hands, but do not pack it too tightly.
6. Water thoroughly. Add a 3-inch layer of compost or mulch around the base of the plant. This will keep the roots moist and cool while the plant gets established in its new location.

Peony Care

Here is an overview of the basic and main care requirements for growing a peony plant:

• Place peonies in a spot with six or more hours of full sun.
• Plant peonies in well-drained, slightly acidic soil.
• Provide peonies with 1 to 2 inches of water weekly.
• Hardy to USDA zones 3 to 9, know that peonies require a chilling period of around six weeks of temperatures below 40°F in the winter to set spring buds.
• Right after blooming, feed peonies with a mix of compost and a small amount of fertilizer once a year.

Light

Peonies need a location that receives at least six hours of sun each day and a full day of sun is even better. Without sufficient sunlight, you’ll get fewer blooms and smaller flowers, and the plants will have a greater risk of fungal diseases.

Soil

Peonies are adaptable but prefer a well-drained, slightly acidic soil (6.5-7.0 pH). If you are planting in heavy, clay soil, amending with compost or a soil mix labeled for azaleas and rhododendrons will help your peony settle in. Since peonies can remain in the same spot for nearly 70 years, the time is well spent preparing the soil before planting.

Tree peonies like slightly more alkaline soil than standard herbaceous peonies and do not want to compete with other shrubs.

Water

Peonies need moist, well-drained soil to thrive. Ideally, they should receive 1 to 2 inches of water weekly. They can thrive in relatively wet areas but are not drought-resistant. Mulch your peonies to help them retain water and lessen the likelihood of weeds.

Temperature and Humidity

Peonies prefer cooler areas (hardiness zones 3-8) and do best when they experience cold winters.

Fertilizer

Feed peonies lightly. An annual application of compost mixed with a small amount of fertilizer around the base of the plant is all that is needed. When you feed with compost and fertilizer, do it just after the plants have finished blooming.

Don’t smother peonies withmulch in winter. In the first winter season, you can mulch loosely with pine needles or shredded bark, but mulch should be promptly removed in spring.

Tree peonies need iron and phosphate and do well with an annual feeding of sulfate and bone meal in spring. Unlike herbaceous peonies, they prefer regular feeding with a 5-10-5 fertilizer.

Types of Peonies

• 'Big Ben': This peony boasts magenta flowers, 5 to 6 inches wide, and a heady aroma. It grows 3 feet tall and wide.
• 'Festiva Maxima': This variety shows white blooms with specks of magenta, growing 3 feet tall and wide.
• 'Pillow Talk': This variety offers giant pink flowerheads with touches of yellow and grows around 2½ feet tall.
• 'Spider Green': This unique peony has a yellow center and large white, separated petals.
• 'Sweet Marjorie': This variety grows around 2½ feet tall and presents hearty, dark-pink blooms 5 inches wide.

Pruning

Peonies require little pruning. Once yours has finished blooming, cut back dead stems and branches. If a stem appears diseased, cut back before the affected part. If two branches rub against each other, remove the least desirable branch. When pruning peonies, always cut back to right above the first bud.

Propagating Peonies

Peonies are best propagated by lifting and dividing the root clump, then immediately replanting the divided pieces. A peony may require this after about 10 years when it begins to lose its vigor and becomes root-bound. Here, too, fall is the best time for this activity. To propagate peonies, you will need a hose and a sharp knife. Follow these steps to propagate peonies:

1. Just before you plan to divide, cut the foliage of the peony back down to ground level.
2. Dig up the entire plant and remove as much soil as possible by soaking it with a hose.
3. Using your hands, manipulate the roots into dividable portions, each with three to five "eyes"—small reddish buds that resemble potato eyes—then use a sharp knife to cut the tuberous root clump into divisions.
4. Cut away all the tiny roots on each division, leaving only the large, fleshy roots.
5. Replant the divisions as soon as possible, following the instructions above.

How to Grow Peony From Seeds

Growing peonies by seed takes patience—it can take three years to develop seedlings, and it can take three to five years for the plant to bloom. For the most success, planting fresh seeds as soon as they are collected in summer or fall will increase the chances of germination. Use black seeds, the red seeds are not viable. Here's how to grow peony plants from seeds:

1. Designate a spot with full sun and well-draining soil to nurse these seedlings for two to three years.
2. Press seeds ½ inch deep into the soil, spaced 1 to 2 inches apart.
3. Cover the seed bed with a layer of fine wood mulch and a clear plastic sheet. Secure the plastic by burying the edges under soil or using rocks.
4. Remove the plastic in the early spring before the last frost while nighttime temperatures are still freezing.
5. It can take up to three years for seedlings to develop, with three or four true leaves, before they can be moved to their permanent location.
   

Potting and Repotting Peonies

Peonies are not typically grown in pots but if they are, their large root systems require a container at least 18 inches wide and deep. Potted peonies need full sun and demand more water. Dwarf varieties are the most suitable peonies for pots. To overwinter, move the pots to a garage or sheltered patio to shield them from the elements, and cover the roots with mulch to protect the plants from freezing.

Overwintering

Before winter, cut peonies down to ground level and remove leaves and debris. This will reduce fungal spores from lingering into spring to reinfect your peonies.

Common Pests & Plant Diseases

Peonies are especially prone to gray mold (botrytis). Combat this by making sure peonies are not planted too closely to each other so air does not circulate between plants. Using copper soap fungicides helps as well.

Gardeners often find peony blossoms covered by ants attracted to nectar secreted by the highly fragrant flowers. The ants do not harm the plant and can deter other floral-feeding insects that might carry disease or otherwise cause damage. The ants are likely an unwelcome addition to your cut flower bouquet. Give your cut peonies a gentle shake before bringing them indoors for decoration.

How to Get Peonies to Bloom

Bloom Months

Peonies typically bloom in early spring and summer between April and June.

What Do Peony Flowers Look and Smell Like?

Peony flowers can range widely in color, form, and scent. Flowers can be 3- to 6-inches in diameter with petals in single, semi-double, or double forms. Blooms can be white, pink, rose, red, purple, and coral with a heady fragrance or no detectable scent. Fragrant peonies can smell like roses, spice, citrus, or slightly sweet.

How to Encourage More Blooms

Give peonies at least six hours of sunlight daily. Ensure they are planted no more than 2 inches deep and fed lightly once a year. Lack of sunshine, smothering the roots and eyes, and too much nitrogen can stunt blooming. Deadhead peonies after the blooms have faded and as they wilt.

Common Problems With Peonies

Gray Mold

Gray mold on flowers, leaves, and stems can indicate botrytis blight, a fungus that can grow in cool, rainy weather. Remove and destroy affected parts of the plant. Cut down to the base if necessary. Remove debris, use ground irrigation, and improve air circulation. Use a fungicide as a preventative.

Powdery Leaves

Powdery mildew can grow on peony leaves when there’s too much shade or plants are crowded. Peonies need at least six hours of full sun and good air circulation.

Brown or Black Spots

A peony with dark brown or black spots on leaves, sometimes including root and crown rot, could have phytophthora blight, which stems from poor drainage. Remove affected parts of the plant, improve drainage, and avoid overwatering.

Dark Splotches on Leaves

Hot, humid weather can cause peony leaf blotch. Cut the peony to ground level in fall or early spring, improve air circulation, and use ground irrigation.

From: thespruce