Corydalis scouleri
Western Corydalis is a graceful, upright to arching woodland perennial that thrives in shady habitat gardens. Throughout spring and early summer, it produces voluminous stems of finely-divided blue-green leaves. Then, this lush, fern-like foliage becomes accented by numerous pinkish-purple tubular flowers in long spikelike clusters, which give the plant a luminous presence before it recedes with the heat of mid-summer. Beyond its beauty, its blooms are an important nectar source for native pollinators such as bees and hummingbirds, adding meaningful ecological value to shaded garden spaces.
- Plant type/canopy layer: deciduous, perennial, herbaceous plant
- Size at maturity: 12-48” tall, equally wide
- Light requirements: partial to full shade
- Moisture requirements: moist to seasonally wet soil
- Bloom time: April - June (April - May in the Portland Metro area)
- Growth rate/ease: medium growth rate, moderately difficult to grow
- Wildlife support: flowers attract and provide nectar to hummingbirds, adult butterflies, bees and other insect pollinators; overall plant is a caterpillar host plant and larval food source for native butterflies and moths
- Native habitat/range: grows in cool, moist, shady woodlands, streambanks and roadsides at low elevations up to 1100m, from the coast to the Western Cascades in Oregon, Washington and British Columbia. Portland Plant List - yes.
- Special features & uses: hummingbird favorite; landscape uses include pollinator gardens, raingardens and woodland gardens
Gardening with Western Corydalis: This show-stopping, shade-loving species will flourish in cool areas of your habitat garden, that best mimic its native woodland home. For the healthiest plants, be sure the soil is consistently moist, well-drained and rich in organic matter. Mulch with leaf litter (or, better yet, just “leave the leaves”) to conserve soil moisture, avoid disturbing the roots, and allow the plant to go dormant naturally after flowering. As it establishes, be sure to water it deeply, but infrequently, during dry spells. You may choose to continue providing supplemental water if your goal is to prolong its lusciousness into mid-summer. In the right conditions, it will spread slowly, enhancing your woodland understory with its elegance.
Try it in the understory of native trees such as western hemlock (Tsuga heterophylla) Douglas fir (Pseudotsuga menziesii) and bitter cherry (Prunus emarginata) and vine maple (Acer circinatum) and amongst shrubs such as evergreen Huckleberry (Vaccinum ovatum), red twig dogwood (Cornus sericea), salal (Gaultheria shallon) and osoberry (Oemleria cerasiformis). Down on the ground, its airy form pairs beautifully with native ferns, slender-foot sedge (Carex leptopoda) and spring ephemerals such as streambank violet (Viola glabella), Pacific bleeding heart (Dicentra formosa), Western buttercup (Ranunculus occidentalis) and candyflower (Claytonia sibirica).
Photo Credit 1 (leavesflowers): © Dominic Gentilcore, some rights reserved (CC-BY)
Photo Credits 2 & 3 (baby leaves and young plant): © giantcicada, some rights reserved (CC-BY)
Photo Credit 4 (foliage): © Gavin Slater, some rights reserved (CC-BY)
Photo Credit 5 (flowers): © rappman, some rights reserved (CC-BY)
Photo Credit 6 (flowering habit): © John Hibbard, some rights reserved (CC-BY)
Photo Credit 7 (mature streamside clump): © Ryan Sorrells, some rights reserved (CC-BY)
Photo Credit 8 (with nettle): © Kieran Hanrahan, some rights reserved (CC-BY)