What hardiness zones is Corydalis suitable for?

Corydalis is suitable for USDA hardiness zones 4, 5, 6, 7, 8, 9.

How much water does Corydalis need?

Corydalis has Medium water needs.

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Perennials

Corydalis spp.

fumewort

PapaveraceaeAsia, Europe, North America

At a Glance

TypePerennial

HabitMounding

FoliageDeciduous

Height6–36 inches (15–90 cm)

Width8–24 inches (20–60 cm)

Maturity1 years

Growing Zones

USDA Hardiness Zones

4 - 9

Zone 4

Zone 5

Zone 6

Zone 7

Zone 8

Zone 9

These zones indicate the coldest temperatures this plant can typically survive.

Frost Tolerancehardy

Key Features

Attracts Pollinators

Attracts Butterflies

Deer Resistant

Container Friendly

Native to North America

Maintenancelow

Overview

Corydalis is a large genus of approximately 500 species of annual and perennial herbaceous plants in the family Papaveraceae, distributed across temperate regions of the Northern Hemisphere with greatest diversity in China and the Himalayas. Plants range from small spring ephemerals a few inches tall to robust perennials exceeding 3 feet (90 cm), united by finely divided, fern-like compound foliage and distinctive tubular spurred flowers with four petals — the uppermost bearing a nectar-containing spur attractive to long-tongued bees. Species vary greatly in flower color, from yellow and white to blue, purple, and pink. Several species are important ornamental garden plants in Pacific Northwest conditions, including the golden-yellow Corydalis lutea, long-blooming and self-seeding in rocky walls and shaded borders, and the electric blue Corydalis flexuosa, a spring-blooming perennial suited to woodland gardens. Many Corydalis species are summer-dormant. The genus is notably the only dicot group known to possess a single cotyledon. Toxicity varies by species; some contain alkaloids and should be handled with care.

Native Range

The genus Corydalis is native to temperate regions of the Northern Hemisphere, with approximately half of the roughly 500 species originating in China and the eastern Himalayas. Additional species occur across central Asia, Europe, Japan, and eastern North America. Several North American species are native to the Pacific Northwest, including Corydalis scouleri and Corydalis aquae-gelidae, both inhabitants of cool, moist forest streambanks. European ornamental species such as Corydalis lutea are widely naturalized in Pacific Northwest gardens and urban environments.

Suggested Uses

Corydalis species are versatile shade garden plants suited to woodland borders, rock gardens, shaded wall crevices, and naturalistic underplanting beneath deciduous trees and shrubs. Yellow-flowered Corydalis lutea is particularly valued for its ability to colonize difficult dry-shade conditions and stone walls. Blue-flowered Corydalis flexuosa pairs well with hostas, ferns, and spring bulbs in sheltered woodland settings. Spring-ephemeral species are ideal companions for other early bulbs and woodland wildflowers that emerge before tree canopy closes.

How to Identify

Corydalis species are identified by their finely divided, two- to four-times compound leaves with a delicate, fern-like texture and glaucous to blue-green coloration in many species. Flowers are tubular and bilaterally symmetrical, with four petals: two outer petals with the upper one extended into a prominent nectar spur at the base, and two narrower inner petals fused at the tips enclosing the stamens. Flowers are borne in terminal or axillary racemes. The combination of finely divided foliage and distinctively spurred tubular flowers is diagnostic for the genus.

Appearance

Size & Dimensions

Height6" - 3'

Width/Spread8" - 2'

Reaches mature size in approximately 1 years

Colors

Flower Colors

yellow

blue

pink

purple

white

Foliage Colors

green

blue green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~6 weeks

Spring

Bloom time within the genus varies widely by species and type. Spring-blooming species such as Corydalis solida and Corydalis flexuosa flower from March through May, going summer-dormant by June or July. The yellow-flowered Corydalis lutea is notable for near-continuous bloom from spring through autumn, flowering April through October in Pacific Northwest conditions. Summer-dormant species typically complete their entire growth cycle — emergence, flowering, and senescence — within eight to twelve weeks.

Detailed Descriptions

Flower Description

Yellow, blue, pink, purple, or white depending on species

Foliage Description

Blue-green to medium green

Growing Conditions

Sun Requirements

Partial Shade

Full Shade

Requires 1-4 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 Range5.5 - 7.5(Neutral)

357912

Soil Types

loamsandrocky

Drainage

well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1–2 years

Care & Maintenance

Care Guide

Cultural requirements vary significantly by species. Most ornamental Corydalis perform best in cool, moist, humus-rich, well-drained soil in partial to full shade, though Corydalis lutea tolerates drier conditions and establishes readily in rock walls and pavement cracks. Spring ephemerals such as Corydalis solida require minimal care — plant tubers in autumn 3–4 inches (8–10 cm) deep and allow summer dormancy. For Corydalis flexuosa, maintain consistent moisture during the growing season and provide afternoon shade in warmer sites. Self-seeding species like Corydalis lutea require periodic editing to prevent unwanted spread. Most species require no fertilization in organically rich soils; top-dress annually with leaf mould or compost.

Pruning

For summer-dormant species, allow foliage to yellow and collapse naturally before clearing; removing foliage prematurely reduces carbohydrate storage in tubers or rhizomes. For continuously blooming species such as Corydalis lutea, no deadheading is necessary, though shearing back plants by one-third in midsummer can refresh tired foliage and encourage continued flowering into autumn. Remove dead stems at the base in late autumn or early spring before new growth emerges.

Pruning Schedule

summer

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 2 gallons

⚠️ Toxicity Warning

Unknown