Herbaceous peonies (Paeonia hybrids and cultivars) form clumps about 60–90 cm tall and 75–90 cm wide. Their showy flowers may be white, pink, red, magenta, coral, yellow or bi-coloured. Plants emerge in early spring, bloom from late spring into early summer, and retain attractive foliage through summer when moisture is adequate. Stems and leaves naturally decline and blacken after autumn frost. These are long-lived perennials, commonly used as border plants, specimen clumps, foundation plantings, mixed-bed plants and cut flowers.

Where it grows best

Choose full sun, with partial shade acceptable. Deep shade can reduce flowering. In warmer southern and western regions, afternoon shade or a cooler site with morning sun may help flowers last longer and foliage remain attractive. Plant in humus-rich, fertile loam that is well drained and moderately moist, with a preferred soil pH of 6.5–7.5. Avoid waterlogged sites, standing water, heavy clay and very sandy, rapidly draining soil. Herbaceous peonies are rated for Canadian hardiness Zones 2–8 and require winter chill to flower well.

Garden and wildlife value

Large flowers provide strong ornamental interest and are excellent for cutting. Flowers may be visited by bees, hoverflies and butterflies. Ants commonly visit the buds for nectar, although they do not pollinate the flowers. Herbaceous peonies are not native to North America and are primarily cultivated hybrids and cultivars derived from Eurasian Paeonia species. They are generally deer-resistant or rarely damaged.

Everyday care

Keep soil evenly moist, especially in spring and early summer, without creating standing water. Once established, water deeply during dry periods rather than using frequent light sprinkling. Increase irrigation during hot spells or when plants are grown in containers, where drying risk is moderate. Routine care is generally low to moderate. Staking or another support system may be useful where stems could flop.

What to do through the season

In spring, monitor moisture as shoots emerge and flower buds form. During late spring flowering, deadhead spent blooms promptly and remove fallen petals from around the plant. After the first hard frost, cut herbaceous stems and all foliage close to ground level, then remove the debris to reduce fungal disease carry-over. In warmer climates, cut back in late autumn to support dormancy. Divide or transplant dormant plants in fall.

Problems and symptoms

Wet conditions can increase the risk of botrytis and other fungal diseases. Poor drainage, waterlogging and heavy clay can cause poor performance and root problems, while very sandy soil may drain too quickly. Plants may flop, particularly when flower heads are heavy or conditions are wet. Flowering may be reduced in deep shade. Drought can also reduce performance, especially during active growth, bud formation and flowering.

Corrective and preventive care

Start with a well-drained planting site and avoid standing water. Maintain moderate, even moisture, then water deeply during dry periods and hot spells. Provide support as stems emerge if flopping is a concern. Remove spent flowers and fallen petals, and cut and remove all foliage after frost rather than leaving diseased material in the bed. In warm regions, provide morning sun and afternoon shade and maintain regular deep irrigation.

Before you plant

Allow about 75–90 cm between plants for mature clumps. Confirm that the site receives full sun or suitable partial shade, has fertile loam with good drainage, and can maintain moderate moisture without becoming waterlogged. Consider the plant’s mature size, need for winter chill and possible support. For propagation or renewal, plan division of crowns in fall while plants are dormant.