Peonies: planting, pruning and care

Description and botany

Genus Paeonia, comprising 33 deciduous species, originates mainly from temperate Eurasia, with two species native to North America. Peonies, formerly classified within Ranunculaceae — family that includes anemone and buttercup — are now recognised as forming their own family, Paeonaceae. Among them, Chinese peonies (Paeonia lactiflora) stand out for their significant contribution to the diversity of herbaceous cultivars, while the varieties suffruticosa, delavayi and lutea have enriched the range of shrub peonies.

These plants are characterised by a woody stump bearing fleshy, robust roots, ensuring remarkable longevity, sometimes lasting centuries. Their deciduous foliage is made up of dentate or lobed leaflets, giving shrub species a particular elegance, and some, such as Paeonia tenuifolia, display finely divided leaves. From spring, peonies announce their awakening with the opening of large red buds, either from the ground for herbaceous types or on branches for shrubs, revealing foliage initially mahogany that develops into a vibrant green.

In autumn, herbaceous peonies can put on a display of purple, ochre and bronze colours, especially after a sunny, moderately dry summer. However, it is advisable to accompany these queens of the garden with other flowers to maintain visual interest until leaf fall in September.

Flower buds, solitary and conspicuous at stem tips, herald a flowering that perfumes the surrounding air over about fifteen days, and even up to a month for Itoh hybrids. Each flower at full bloom, however, lasts only one to two days, offering an ephemeral moment of pure beauty.

Paeonia officinalis, a European species, is notable for its simple, bright red flowers. Highly scented, these flowers have more than five rounded petals, evoking the look of large wild-rose blooms with their short yellow stamens. In double-flowered varieties, these stamens are replaced by undulate filaments, creating an especially captivating visual display. Paeonia officinalis conceals between two and five large ovaries which, after fertilisation, develop into compact, villous follicles. It is important to note the toxicity of the seeds, which are large enough to attract attention.

Pollination of peonies, essential to their reproduction, benefits greatly from bee activity. However, many cultivars, notably double- or triple-flowered peonies, present an impressive array of transformed stamens, either into curled filaments in varieties such as Paeonia lactiflora ‘Bowl of Beauty’, or into extra petals in specimens such as Paeonia officinalis ‘Rubra Plena’ or Paeonia lactiflora ‘Felix Crousse’. These transformations offer a range of colour variations, from delicate gradations to distinctive purplish touches, with flower sizes from 5 to 30 cm in diameter. Some, particularly among shrub peonies, can become so heavy that they lean or even flop to the ground, recalling the morphological diversity of dahlias.

Flowering of peonies requires patience and time, often two to three years after planting to establish firmly. Once well rooted, peonies can flower for a century, producing up to 60 flowers per plant. Shrub varieties require an even longer period, around seven years, to fully reveal their splendour, which explains price increases with plant age. When purchasing, pay attention to the size of the stump, the number of eyes or branches, these being indicators of the age and ripeness of the plant.

Cut peonies, in particular, make splendid additions to bouquets, pairing perfectly with lilac and bellflowers, and should ideally be picked in the morning at the coloured-bud stage.

Beyond their beauty, Paeonia officinalis has medicinal virtues, reflecting its Greek name “Paeonia”, meaning “salutary”. This name may also derive from Paeon, a physician of ancient Greece. Pliny the Elder already considered the peony to be the oldest cultivated flower, testimony to its historical and cultural importance.

Some peony flowers: Paeonia lactiflora ‘Black Beauty’, Paeonia itoh ‘Julia Rose’, Paeonia lactiflora ‘Bowl of Beauty’ and Paeonia delavayi lutea

Main peony varieties

Herbaceous varieties with single flowers

Herbaceous varieties with double flowers

Bush varieties

Paeonia lobata Sunshine

Arguably the best of varieties derived from botanical species, this perennial rare in cultivation produces single, globular, shimmering flowers of a rare and brilliant red, a light gooseberry red shaded with orange and further highlighted by a large heart of golden stamens. Its luminous flowering makes a very beautiful backdrop in a border or a large rockery.

• Flowering time May, June
• Height at maturity 85 cm

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Paeonia officinalis Mollis

Its deciduous foliage, green tinged with purple, provides a setting for beautiful single, chalice-shaped flowers of a true vivid pink with no trace of blue, opening to a heart of deep yellow stamens. Flowering sometimes repeats in July. Plant in sun or partial shade, in calcareous, fertile, loose soil that remains cool.

• Flowering time July, August
• Height at maturity 45 cm

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Paeonia tenuifolia

Very fine foliage reminiscent of fennel topped by beautiful cup-shaped, ephemeral flowers of scarlet red. Deciduous foliage is dense and particularly fine, a brilliant dark green. Grow in sun or partial shade in a warm site, in moderately dry soil.

• Flowering time May
• Height at maturity 40 cm

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Paeonia lactiflora Bowl of Beauty

Excellent cut flower, this Japanese-type peony consists of two rows of petals of carmine pink and a large yellow heart turning to cream-white. Flowers measure up to 12 cm in diameter and are grouped on stems.

• Flowering time June, July
• Height at maturity 90 cm

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Paeonia lactiflora Do Tell

Japanese-form peony, particularly floriferous, with upright stems flecked with red, topped by large solitary, elegant and fragrant single flowers 7 to 10 cm across. Pale pink corolla bearing a petaloid heart of lilac-pink that fades at end of flowering.

• Flowering time June
• Height at maturity 80 cm

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Paeonia lactiflora Inspecteur Lavergne

An old, reliable peony with large pompon flowers of a deep carmine pink, fairly pure, anemone-shaped, borne on sturdy stems with impeccable performance in garden and vase.

• Flowering time June, July
• Height at maturity 80 cm

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Paeonia Itoh Julia Rose

Hybrid between a bush peony and an herbaceous peony, characterised by vigorous growth and the production of flowers similar to those of bush varieties. Semi-double flowers 16 cm across shaded with pink and apricot on a soft yellow background, borne on sturdy stems.

• Flowering time June, July
• Height at maturity 75 cm

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Paeonia suffruticosa Pink - Tree Peony

Bush peony with solitary, double flowers 15 to 18 cm across, shaded pale pink with a vivid pink centre, furnished with yellow stamens. Suited to warm situations sheltered from cold winds, in partial shade or non-burning sun, in well-drained, rich, humus-bearing, cool soil.

• Flowering time May, June
• Height at maturity 1,50 m

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Paeonia suffruticosa Lilac - Tree Peony

Bush peony with solitary, semi-double, open cup flowers 18 to 25 cm, lilac-pink maculate with black and pale yellow stamens. Flowering from mid-May to mid-June.

• Flowering time June, July
• Height at maturity 1,50 m

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Paeonia suffruticosa Lu Mu Ying Yu - Tree Peony

Hybrid variety forming a bush at least 1.50 m in every direction, with exquisite, fragrant flowers reaching 20 cm in diameter, fully double, whose crisped petals range from tender green to cream-white. Sculptural in borders or as a specimen, this rare variety also offers excellent cut flowers. Suited to any rich, cool soil. Sensitive to late frosts.

• Flowering time May, June
• Height at maturity 1,50 m

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Paeonia suffruticosa Wu Jin Yao Hui - Tree Peony

Luxurious, floriferous and robust bush peony within reach of beginner gardeners. The bush, of spreading habit, produces numerous rose-shaped flowers, slightly scented, 16 cm wide, composed of multiple petals of a very dark red with a glossy sheen. Give it a bright exposure and good, well-drained garden soil.

• Flowering time May
• Height at maturity 1,50 m

See the product sheet

Planting peonies

Where to plant peonies?

Peonies dislike being moved, so it is important to choose best possible spot so they are well displayed and, above all, do not suffer from excess moisture or competition from other plants. Bear in mind you are planting for next two generations!

• Herbaceous peonies require sun or part shade with heavy (clayey), rich, well-drained but remaining cool in summer, neutral, slightly acidic or calcareous soil (ideal pH between 6 and 7). Growth is slow there but flowering is more beautiful than in dry soil. Very sandy, free-draining soil produces lots of foliage with few flowers. You can lighten soils that are too wet in winter by adding some compost or leaf mould or by planting on a raised bed.

Itoh peonies appreciate semi-shaded locations such as woodland edge or shelter of a hedge and also require rich, cool, deep and well-drained soil.

• Place tree peonies in a warm position, west-facing, sheltered from severe frosts and cold winds. Choose a sunny but not scorching to lightly shaded position (4 to 6 hours’ sun per day). Buds and young leaves are sensitive to late frosts.

Tree peonies prefer rich, humus-bearing, deep, cool and well-drained soil and tolerate lime well. They dislike very heavy, waterlogged soils in winter. Of slow growth during first years, tree peonies form a powerful, deep root system and produce few branches; it is only after 3–4, sometimes 5 years of culture that branching develops and flowering becomes spectacular. Mature plants do not like being moved.

For more information read Planting peonies: where, when and how? and How to get beautiful peonies in garden?

When to plant?

Plant herbaceous peonies preferably in autumn so they have time to establish.
For tree peonies, spring planting is preferable, especially if winters are severe.

How to plant?

This plant is somewhat capricious and sometimes takes a long time to flower.

• Dig a hole 40 to 50 cm deep.

To check whether soil drains sufficiently, dig a hole 30 cm deep and 20 cm wide and fill with water. After one hour, water must have completely drained away.

• Lay a 10 cm layer of gravel and lighten soil with coarse sand if necessary.
• Add well-rotted manure or blood meal to planting hole to stimulate flowering.

For herbaceous peony, position the crown of roots (griffe) less than 3 cm deep and space 60 cm to 1 m apart.

Roots of herbaceous peony (photo F. D. Richards – Flickr)

For tree peony, do not hesitate to bury graft union 10 cm deep so scion can produce its own roots. Indeed, grafting onto an herbaceous peony reduces longevity of tree peony. In addition, too shallow planting causes rootstock to send up shoots. However, keep same level as substrate if young plant is sold in container.

• Replace soil and firm lightly.
• Insert stakes such as hazel branches to support large flowers and mark location.
• Water generously.
• Avoid mulching with organic waste to prevent disease transmission. Instead plant low-competition groundcover such as hardy geranium or Sedum.

Care

• Apply well-rotted manure or blood meal every autumn at 15 cm from plant base. Avoid fresh manures!
• If an exceptional frost affects shoots of tree peony, and if you have buried the graft union, cutting shoots back to ground level in April allows branches to regrow within a year.
• During first years, water peony in dry spells, especially in spring before flowering.
• Cut faded flowers to avoid exhausting plant with seed production.

• In general, herbaceous peony does not require clump division, unless flowering declines. Tree peony is pruned little or not at all (thin or crossing branches).
• Peonies are little susceptible to diseases except in case of excessive soil moisture (white rot) or in the air (grey mould, rust), notably in herbaceous peonies. Cut diseased parts back to healthy tissue, spray 2% Bordeaux mixture or horsetail decoction as a preventive and do not leave plant debris at base. Rose chafers sometimes eat the flowers without serious consequences.

Clump of herbaceous peony in early spring

Propagation: dividing peonies

Shrub peonies are generally grafted onto roots of herbaceous peonies because propagation by cuttings is not easy. It is a specialist job. This propagation involves 2 to 3 years’ cultivation in a nursery, which explains their high cost.

Clump division is possible with herbaceous peonies and is obligatory if you move the plant, otherwise it may not flower again. Carry out in autumn or early spring.

Clump division

• Lift whole clump without damaging roots using a garden fork.
• Divide clump with a sharp knife, ensuring each division retains 3 to 5 roots and 3 to 5 eyes.
• Replant with eyes placed no more than 3 cm below surface.

→ Learn more in our tutorials: How to divide a herbaceous peony? and How to propagate a shrub peony?

Uses and companion plants

Peonies used to be among those plants that formed backbone of a garden. Every garden, from humblest to most elaborate, would proudly display in spring clumps covered with fragrant flowers that made their way into house, accompanying each bouquet with mauve lilac and blue campanulas. Japanese peonies fit perfectly into a mixed border alongside timeless perennials such as columbines, delphiniums, campanulas, irises, alyssums, carnations, foxgloves, lupins or Christmas roses, or ferns where area is semi-shaded. Just make sure to leave them enough space so they don’t compete. Only long-term container culture is not advised, as their needs will not be met. Over time, peony becomes majestic, multiplies and flowers more and more abundantly. It can also be planted at foot of a standard-trained rose. Planted singly, space 3 young plants 60–100 cm apart to create a spectacular effect.

An example of a combination: Paeonia lactiflora ‘Félix Crousse’, Geranium pratense ‘Mrs Kendall Clarke’, Rose ‘Astronomia’, Geranium ‘Johnson’s Blue’ and Rose ‘Munstead Wood’

The Itoh peony appreciates semi-shaded positions such as edge of a copse or shelter of a hedge. It is often planted in groups of 3 specimens in a bed of bushes or perennials.

Botanical peonies (officinalis, tenuifolia, etc.) that favour warm situations can be placed at top of a large rockery, even on limestone, or in a border or planted singly.

Place bush peony alone or framed by other plants depending on exposure, alongside ferns, rhododendrons, hydrangeas in partial shade, or with irises, nepeta, foxgloves, lupins, oxeye daisies, roses in a sunny spot. Consider pairing with plants that will take over summer flowering such as Phlox paniculata, dahlias or asters.

An example of a combination in light shade and fresh soil: Paeonia delavayi lutea (or why not a double-flowered variety such as ‘Alice Harding’), Dryopteris affinis and Iris sibirica ‘Butter and Sugar’ (or a similar variety such as ‘Snow Queen’)

→ Discover other ideas for pairing peonies in our advice sheet !

Did you know?

Herbaceous peony (Paeonia lactiflora), cultivated for more than 1,000 years in the East, was, however, known in Europe only at the end of the 18^th century thanks to a gift to Joséphine from the Emperor of China. The shrub peony, also Asian, was discovered by the West only a century later. There are also peonies native to the West, such as the officinal peony, described by the Greeks as possessing great medicinal virtues.