Overview
A genus of approximately 33 species of perennial herbs and deciduous shrubs in Paeoniaceae, grown in Pacific Northwest gardens primarily as herbaceous peonies (P. lactiflora hybrids), tree peonies (P. suffruticosa hybrids), and intersectional Itoh peonies. Herbaceous types produce large fragrant flowers 4–10 inches (10–25 cm) across in May–June then die to the ground each winter. Tree peonies are deciduous shrubs reaching 3–7 feet (90–210 cm) retaining woody stems year-round, with flowers up to 12 inches (30 cm) across in April–May. Intersectional peonies combine large tree-peony flowers on herbaceous plants. All parts mildly toxic to pets. Long-lived — established clumps may persist 50+ years. Hardy in USDA zones 3–8.
Native Range
Paeonia lactiflora (herbaceous peony) is native to Siberia and China. P. suffruticosa (tree peony) is native to western China and has been cultivated in China and Japan for over a millennium. Intersectional Itoh peonies are hybrids of Japanese garden origin developed in the 1940s.Suggested Uses
Planted in mixed borders, cottage gardens, and cutting gardens at 3–4 foot (90–120 cm) spacing. Herbaceous peonies (P. lactiflora) are among the longest-lived perennials — established clumps may persist and flower for 50 years or more with minimal care. Tree peonies (P. suffruticosa) provide a shrub-scale flowering specimen for late April–May color with extraordinarily large blooms. All parts mildly toxic to pets.How to Identify
Appearance
Size & Dimensions
Height2' - 7'
Width/Spread2' - 5'
Reaches mature size in approximately 4 years
Bloom Information
Herbaceous peonies (P. lactiflora) bloom May through June, for 1–2 weeks per cultivar — planting multiple varieties extends the season. Flowers 4–10 inches (10–25 cm) across, single to double, fragrant in many cultivars. Tree peonies (P. suffruticosa) bloom late April through May, slightly ahead of herbaceous types, with even larger flowers. Intersectional peonies bloom May–June, often with longer season than herbaceous types.Detailed Descriptions
Flower Description
Large, 4–12 inches (10–30 cm) across, in white, cream, yellow, pink, rose, coral, red, and bicolor; single, semi-double, or double; many are fragrantFoliage Description
Herbaceous types: deeply divided compound-pinnate leaves with 9–15 elliptic leaflets, medium to dark green. Tree peonies: deeply lobed blue-green compound leaves, more texturalGrowing Conditions
Sun Requirements
Requires 5-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Plant herbaceous peonies (P. lactiflora) with eyes (buds) 1.5–2 inches (4–5 cm) below the soil surface — planting too deep prevents flowering. Plant tree peonies (P. suffruticosa) with the graft union 4–6 inches (10–15 cm) below the surface. Full sun essential. Well-drained, fertile, slightly neutral soil (pH 6.0–7.0). Space 3–4 feet (90–120 cm) apart. Water regularly. Stake tall varieties to prevent flower stem breakage in wind and rain. All parts mildly toxic to pets.Pruning
Herbaceous peonies: cut stems to the ground in fall after frost. Tree peonies (P. suffruticosa): remove dead wood in early spring — do not cut back to the ground as the woody framework is permanent. Intersectional peonies: cut stems to ground level in fall, leaving 3–4 inches (7.5–10 cm) of stem. Deadhead spent blooms promptly.Pruning Schedule
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fallearly spring