How to Grow Peonies

Grow Peonies: Beauty queens in the early summer garden...

Peonies are one of our most beautiful and cherished garden plants. Their huge luscious blooms—typically in shades of red, pink and white but sometimes yellow— truly dominate the early summer garden.

Peonies are long-time garden favorites and over the years, for our gardening pleasure, plant breeders have produced a staggering array of cultivars, many with mesmerizing scents. Some are double-fluffy confections, others have an array of outer petals surrounding a froth of smaller petals (or petaloides). Still others have one or two rows of large petals encircling a mass of yellow stamens.

And best of all, given fertile soil, good air circulation and adequate sunlight, peonies are both easy to grow and extremely long-lived.

When and Where to Plant Peonies

Light: Herbaceous peonies should be located where they will receive at least 6 hours of sun a day. While tree peonies (Paeonia suffruticosa), as well as intersectional peonies (a cross between a tree peony and a herbaceous peony) both do best in full sun, they can also take partial shade. Woodland peonies ( Paeonia japonica) require dappled shade.

Soil: Choose a location where the soil will be consistently moist throughout the season, but which does not get waterlogged. Peonies are long lived and, once planted, they resent being moved. So, before you plant, take time to prepare the soil by digging out any existing weeds and their roots, and turning in aged compost or leaf mold throughout the top six inches of the planting area.

Spacing: Space your new peony roots a minimum of 3 feet apart. Eventually most peonies will grow to three to four feet in diameter, so choose a spot where each plant can remain undisturbed for many years.

Peonies will grow into strong, full plants. Be sure to give them plenty of room to grow into maturity.

Fall planting: Be sure to plant your peonies at least one month before you expect the ground in your area to freeze solid. This will give the roots enough time to get established in their new location prior to the onset of winter.

Spring planting: You can also plant peonies in early spring; just remember to water your new plants weekly throughout the first summer, unless you experience adequate rainfall.

Planting: Look for the pinkish buds or ‘eyes’ on the brown fleshy roots. Since these will eventually give rise to the flower stalks, be sure to plant the ‘eyes’ facing upwards. In addition, avoid planting your peony roots too deeply or flowering will be curtailed.

If you live in a cold climate, position the ‘eyes’ between one and two inches below the surface of the soil and the rest of the root angled slightly downwards into the amended soil. If you live in a warmer climate the ‘eyes’ should be an inch or even less below the surface of the soil, allowing them to maximize their exposure to cold winter temps. Mulch the whole area lightly, with no more than an inch of mulch covering the eyes.

How to Grow Peonies Throughout the Season

Growth Habit: While the height varies by cultivar, most peony flowers are around 3 feet high and the leaves are around thirty inches high.

Staking: Some peony cultivars are noted for their short, stout flower stalks which do not need staking. However, to avoid the stalks breaking under the weight of the heavy flowers, most cultivars benefit from staking. Some gardeners use metal ‘peony rings’ which offer an adjustable height. In early spring, position one ring over each plant so that the entire plant will grow up through the supports. Adjust the height as the plant grows so that the flower stalks are supported.

Other gardeners prefer to make their own support system using some garden twine and a circle of bamboo stakes. First, position the stakes in the ground outside the emerging peony stalks. Next run the twine around the circle of stakes. And finally, to support the stems more thoroughly, run the twine in a criss-cross manner diagonally across the circle of stakes.

Watering: Unless you live in a very arid climate, once established your peonies should not require regular watering.

Fertilizing: The occasional light application of a slow-release organic fertilizer will keep you peonies vigorous for many years to come. Sprinkle a little organic fertilizer around the root zone in spring.

Mulching: Use a light layer of bark mulch over the outer root zone.

Trimming & Pruning: Remove all spent flower heads. If any stems turn black during the summer this can be a sign of fungal disease. Cut off the diseased portions and dispose of separately—do not add to your compost pile.

Peonies: End of Season Care

Overwintering: Sprinkle about an inch of chopped leaves over the roots as a winter mulch. To avoid spreading fungal diseases, do not dispose of spent peony leaves into your compost bin.

Dividing & Transplanting: Unless you need to thin them out, you do not need to lift and divide your peonies. If necessary, peonies can be divided in early fall and replanted according to the guideline above.

Pests & Disease: Various fungal blights, especially Botrytis, can potentially attack peony plants. To avoid fungal diseases, plant your herbaceous peonies in full sun where there is good air circulation and avoid overhead watering.

To learn more about the plants we sell and how to grow them in your garden beds and patio containers, sign up for our inspiring emails.