A Chorus of Corydalis

March, 2022

If one word might convey the effects brought to the garden from the genus of Corydalis, I would consider “bejeweled”.

Dan Hinkley, Heronswood catalog, 2003

Enchantment came easily on my first acquaintance with corydalis (pronounced koh-RID-ah-liss) as a novice gardener about 30 years ago. Hooked at the time by the cottage garden look, I found utterly charming the cheerful yellow mounds of Corydalis lutea, with billowing, lemony blooms riding atop glaucous, finely cut, ferny foliage. Its elegant and somewhat shier ivory cousin, C. ochroleuca,¹ quickly tagged along, and both have become steady if somewhat itinerant (given their tendencies as short-lived but ready self-sowers) garden residents ever since. 

Just a few years later this unfussy pair was nearly eclipsed into irrelevance when about a dozen dazzling and ethereally dreamy, blue-flowered cultivars of the Chinese species C. flexuosa burst onto the scene. As British garden luminary Graham Rice wrote in 1995, “Corydalis flexuosa must be the plant of the decade.” With alluring names such as ‘Blue Panda,’ ‘China Blue,’ ‘Golden Panda,’ ‘Nightshade,’ ‘Pere David’ and ‘Purple Leaf,’ these posh and pricy forms brought out an uncharacteristic panting, covetous and grasping aspect in many a Pacific Northwest gardener —or at least in me, for a while.

Let’s back up for a bit of background as I catch my breath. A member of Papaveraceae (the poppy family), the genus Corydalis² comprises around 300 species found in most parts of the temperate Northern Hemisphere. There is an attractive, rhizomatous PNW native, Corydalis scouleri, common in Western Washington and Oregon along shaded, low-elevation stream banks. Its rosy-lavender flowers rise on stems that can reach 5 feet. As indicated by “Corydalis: Jewels in Many Hues,” the title of Chapter 7 in Dan Hinkley’s essential book³, The Explorer’s Garden, blossoms in the genus as a whole cover the color wheel, from the whites, yellows and blues already mentioned to the pinks, reds and purples we’ll discuss below.

Eventually burned by the prima-donna demands of the blue bloods, my fascination for them faded. Neglect settled in and my azure collection withered and waned just as I was initiating a firmer and more reliable relationship with the tuberous C. solida. Native to a wide swath of Eurasia, from Sweden and the Baltic States south to Romania and eastward across Western Asia, these cold hardy and undemanding, low-growing (6 to 8 inches), March-blooming beauties yield rewards year after year. Even though the straight species is rather homely (Dan Hinkley describes its color as “murky puce,”) a host of vividly hued, named cultivars caught my eye and soon thereafter claimed my heart. My favorites are the rosy-pink vigorous grower ‘Beth Evans’, the brick-red ‘George Baker’ and the aptly named ‘Purple Bird.’

Order tubers in bulk and save a bundle. Plant in October along with crocus bulbs, which these corydalis corms closely resemble. If your bulb beds are prone to predation by aggressive squirrels, consider frequent application of cayenne pepper for a few weeks after planting. Also dastardly in my experience is the plague of rabbits: One particularly bad bunny, pictured here, had the audacity to munch several mouthfuls of ‘Beth Evans’ while I was working just inches away. Fortunately, C. solida tubers are strong enough to grow through such insults; you can count on them to bulk up and multiply. After flowering, the spent foliage crisps up neatly and can be effortlessly brushed away with your fingers in May. Their summer dormancy is prime time to lift and divide the clumped tubers. You can either replant right away or keep them dry and shaded for planting in autumn.

On that note, I’ll take leave, as I feel compelled to patrol for marauding rabbits. We’ll meet again on the other side of the vernal equinox.

Horticulturally yours,

Daniel

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1. Although still marketed as Corydalis, both species have been reclassified by taxonomists and assigned to the genus Pseudofumaria. The yellow one keeps its specific epithet and is properly called P. lutea, while the white one is now P. alba.
2. Linnaeus named the genus from the Greek for “crested lark,” as the flower’s shape resembles the prominent spurs on the feet of that melodious ground-nester. Curiously, Linnaeus also coined the scientific name of the bird itself, designating it Galerida cristata, from the Latin for, you guessed it, “crested lark.”
3. A superb trio of resources on the genus Corydalis awaits readers at the UW’s Elisabeth C. Miller Library and at Seattle Public Library:
4. Bleeding Hearts, Corydalis and Their Relatives, by Mark Tebbitt, Magnus Lidén, and Henrik Zetterlund. Published in association with Brooklyn Botanic Garden. (Portland: Timber Press, 2008).
5. Buried Treasures: Finding and Growing the World’s Choicest Bulbs, by Jānis Rukšāns. (Portland: Timber Press, 2007).
6. The Explorer’s Garden: Rare and Unusual Perennials, by Dan Hinkley. (Portland: Timber Press, 1999).