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Paeonia 'Cora Louise'

cora louise itoh peony

Paeoniaceae

Hybrid of garden origin; parent species native to central and eastern Asia

Attracts Pollinators Deer Resistant Fragrant (light)Container Friendly

SunFull Sun – Part Shade

WaterMedium

HardinessZones 4–8

Overview

Paeonia 'Cora Louise' is an Itoh (intersectional) peony — a cross between herbaceous P. lactiflora and tree peony P. suffruticosa — forming a clump 26-32 inches (66-81 cm) tall and 30-36 inches (76-91 cm) wide at maturity. Stems emerge red-tinged in spring, dying back to a woody base 4-6 inches (10-15 cm) above the soil rather than fully to the ground as in herbaceous peonies. Compound leaves are deeply cut and finely divided, dark green with reddish veining, holding shape into autumn before turning bronze. Flowers open in late spring as semi-double blooms 7-9 inches (18-23 cm) across, with white petals overlapping in 2-3 layers; the inner petals show prominent lavender-purple flares radiating from the petal base, surrounding a central boss of golden-yellow stamens. Light sweet fragrance is detectable within 12-18 inches (30-45 cm). Each plant carries 30-50 flower buds at maturity that open in succession over 3-4 weeks, longer than the 7-10 day bloom of herbaceous peonies. Stems are stout enough to remain upright through rain. Itoh peonies are long-lived, with established plants flowering for 25 or more years in the same site.

Native Range

Itoh peonies are hybrids of garden origin, derived from Paeonia lactiflora (native to central and eastern Asia) and P. suffruticosa (native to central China). 'Cora Louise' was bred and introduced by Roger Anderson in the United States in the 1980s and has no native range.

Suggested Uses

Commonly planted as a long-lived specimen or in mixed perennial borders at 36-42 inch (90-105 cm) spacing. Used as a structural backbone in herbaceous borders due to the persistent woody framework and large flowers. Container culture is possible in 20-25 gallon (76-95 L) pots with insulation against winter freeze in zones 3-5; plants typically remain shorter-lived in containers.

How to Identify

Distinguished from herbaceous peonies by woody stems that persist 4-6 inches (10-15 cm) above the soil through winter, and from tree peonies by stems that die back partially each fall. Flowers are semi-double, 7-9 inches (18-23 cm) across, white with prominent lavender-purple flares at the petal base. Foliage is deeply cut and finely divided, more dissected than typical herbaceous peony leaves.

Appearance

Size & Dimensions

Height2'2" - 2'8"

Width/Spread2'6" - 3'

Reaches mature size in approximately 5 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Blooms late May through mid-June in zones 4-7. In zone 8, flowering may begin in late April and end by mid-May. Each plant carries 30-50 buds opening in succession over 3-4 weeks, longer than the 7-10 day bloom of herbaceous peonies. A late hard frost below 28°F (-2°C) damages emerging buds and reduces or eliminates that year's bloom.

Detailed Descriptions

Flower Description

White with lavender-purple flares and golden-yellow stamens

Foliage Description

Dark green with reddish veining

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-10 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

Soil Requirements

pH Range6.5 - 7.5(Neutral)

357912

Soil Types

loam clay

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

4-5 years to peak bloom

Care & Maintenance

Care Guide

Water deeply at planting and weekly through the first 2 growing seasons; established plants tolerate 3-4 weeks without rain. Crowns are planted with eyes 1-2 inches (2.5-5 cm) below the soil surface; deeper planting reduces or prevents flowering. Itoh peonies are slow to establish, often producing only 1-3 buds in the first 2 years, with full flower count reached in years 4-5. Plants resent transplanting and may take 2-3 years to resume normal bloom after division. Botrytis blight develops in cool wet springs, blackening buds and stems; affected tissue is cut off and removed. Cool winters with 400-500 hours below 40°F (4°C) are required to break dormancy; flower production declines in zones 9-10 due to insufficient chilling.

Pruning

Spent flower stalks are cut to a leaf node after bloom to prevent seed formation. Foliage is left intact through summer to allow nutrient transfer to the rhizomes. In late fall after foliage blackens with frost, herbaceous stem portions are cut back to the woody base 4-6 inches (10-15 cm) above the soil; the woody base is left intact through winter and produces new growth from buds at its tip in spring.

Pruning Schedule

summerfall