An essential plant for the shady garden, Corydalis offers sprays of cheerful flowers and delicate, beautiful foliage early in the season.
Finding plants that will bloom well in shady conditions can be a bit challenging, but Corydalis will brighten up even a deep shade spot with very little trouble. The lacy, ferny foliage appears in late winter, and clusters of small, tubular, often fragrant flowers cover the plant from early spring into early summer, and sometimes even longer. A great filler or mass-planted ground cover, Corydalis blends beautifully with other early shade-lovers like bleeding hearts, Narcissus, violets, or primroses.
Ease of care and reliable bloom aren’t the only merits of this sweet little plant. Just look at the color! In addition to lavender and purple, you’ll find cheery bright yellow, and absolutely true blue. Yes, real blue--from azure to electric blue to robin’s-egg shades. And unlike certain other blue-blooming shade plants (we’re looking at you, Himalayan poppy), Corydalis won’t demand much from the gardener at all.
What Corydalis wants is a rich, well-drained soil in a cool spot. It’s primarily a woodland plant, so imagine the fluffy loam of a forest floor. Add plenty of compost to amend the soil, and give it a bit of organic flower food in late winter to keep the blooms coming. Consistent watering is important, but soil should not retain too much water, or the roots could rot, especially when the plant is dormant in winter or late summer. Corydalis tends to die back to the ground and go dormant when summer temperatures start to get hot, but if it is placed in a cool microclimate and gets regular water, you may be able to keep it going well into the summer or even into autumn.
Some varieties you can find at Portland Nursery include:
Corydalis flexuosa species:
8-14” tall and wide with light blue flowers
8-10” with bronze-tipped purplish foliage and blue flowers.
Corydalis lutea, Yellow corydalis
8-14” tall and wide with sprays of bright yellow flowers. Tolerates drier soils than other Corydalis.
Photo Credit: Bouba
Corydalis quantmeyeriana ‘Chocolate Stars’
12-16” tall and wide, with reddish-brown, bronzey foliage that fades to green, and light lavender flowers.
Corydalis ‘Berry Exciting’
10-13” tall and up to 2’wide. Chartreuse foliage and fragrant purple flowers.
Corydalis ‘Blackberry Wine’
8-12” tall and wide with fragrant pinkish-purple flowers.
Corydalis ‘Canary Feathers’
10x10” with spikes of yellow flowers.
Family: Papaveraceae (sometimes categorized Fumariaceae)
Common Name: Corydalis, fumewort
Origin: A large genus native to temperate parts of the Northern Hemisphere, especially China.
Culture: Plant in part sun to full shade. Morning sun or dappled all-day shade is best. Plant in loamy, well-drained soil rich in organic matter. Avoid planting in hot spots in the garden, as Corydalis prefers a cool situation. Needs consistent watering, though Corydalis can’t tolerate poorly drained soils, especially in dormancy. Hardy in zones 5-8.
Maintenance: Easy-care. Regular watering may keep plants from going dormant in the warmer summer months. Some Corydalis, especially yellow varieties (C. lutea), can self-seed prolifically, so keep an eye out for volunteers popping up where you don’t want them to. Divide crowded clumps in the fall or late winter. Transplant carefully.
Pest and Disease: Not usually bothered by pests or diseases. Powdery mildew can sometimes occur. Thin out crowded plants to promote good air circulation.