Corydalis: Dainty Native Perennial for Your Woodland Garden

Corydalis is a small and charming native perennial which deserves a spot in woodland borders. Surprisingly, few gardeners seem to know of the plant and yet, it has a lot to offer when planted in the correct conditions. Once you become familiar with this small gem, you'll want to give it not only a spot, but a spotlight in your garden.

With very lacy, delicate bluish green leaves, Corydalis bears some resemblance to a maidenhair fern, or perhaps bleeding heart, which has given it a common nickname of yellow bleeding heart. Other nicknames include scrambled eggs, fumewort, and turkey corn. It grows about 12" tall, with slim flower stems held above the foliage.

According to the US Department of Agriculture Natural Resources Conservation Service website, Corydalis species are native to most of the US and Canada, except for the Southeastern states. About 300 different species of the plant are known. In the wild, they are threatened or endangered in at least five states.

Being a woodland native, Corydalis enjoys cool, rich soil in shady locations. It can be planted in rock crevices or in a little niche in a wall if the location is shady. While it will withstand full sun when kept cool and moist enough, that's not an ideal location. In the hottest, driest weather, the whole plant can look bedraggled, and even go dormant until cooler fall weather revives it.

Spring is the time of heaviest flowering for Corydalis, but if the plant is happy in it's location, it may flower all through the summer until frost. In my shady Zone 6 front yard, the plant requires no care at all. After a heavy freeze it disappears with no clean up, and at the earliest sign of spring, it reappears. I'm lucky to enjoy yellow flowers from April through frost.

While Corydalis self-seeds easily, it is mild mannered enough that it's not invasive and any unwanted volunteers are easily pulled. As a bonus, this plant is deer and rabbit resistant. Like many lovers of moist shade, Corydalis can fall prey to slugs, but I haven't seen that problem.

In the wild, this plant was used in Native American medicine, but it is actually potentially toxic in some cases, especially to horses, and care must be taken to never allow it to spread into a horse pasture.

New hybrids are available, among them: Corydalis 'Berry Exciting', with yellow variegated leaves and purple flowers, Corydalis 'Blackberry Wine', with fragrant wine-colored flowers, and Corydalis flexuosa 'Blue Panda', which features blue flowers.

Resources:
Department of Horticulture, University of Wisconsin-Madison, Corydalis lutea by Susan Mahr, http://www.hort.wisc.edu/mastergardener/features/flowers/corydalis/corydalis.htm