The corydalis is in the poppy family, but also somewhat related to the dicentra (bleeding heart). It has a number of medicinal uses, for pain relief and circulation issues, among other applications. They have been used in various herbal medicine traditions in Europe, India, and China for centuries. In North America, it also has a history of being used medicinally by Native Americans, and the folk names include turkey corn or squirrel corn, after the bumpy tubers, which are the part used for medicine. In addition to being a useful medicinal plant, the flowers fairly early in spring and so are valuable in the garden landscape for early spring color that persists through summer. The flowers are quite small and delicate with an unusual curving tubular or trumpet shape. Corydalis come in a range of colors depending on variety, from pink to purple to blue, and some white and yellow.

Light

Corydalis are shade lovers, and useful to brighten up shady spots in your garden with color. They can tolerate some sun, but afternoon sun would probably be too much for them, especially in zone 7 during hotter summer temperatures.

Soil

Corydalis flowers like a rich well-drained soil that is not too moist. The roots can be subject to root rot if soil stays too wet, and if your corydalis does not overwinter, either you live in a zone that is too cold (below 5) and/or the soil is too wet and the roots stay frozen.

Temperature and Humidity

Plant corydalis in a cool shady spot. Basic temperate humidity is appropriate for these naturalizing shade plants. These flowers are somewhat fussy about temperature and will not survive in growing zones lower than 5 or higher than 7.

Propagation

Corydalis can be propagated by seed, division or separating plants. They self-sow readily, so one suggestion is to ask a gardening friend for a division of them! Most yards with corydalis growing should have plenty to spare. Or get some fresh seed, as packaged seed does not to tend to germinate as well. Collect seed in the fall, plant in containers and the plants should germinate in spring.