When grown in the ideal environment, yellow corydalis is even sometimes considered to be weedy due to its prolific growth, however, it is easily removed where it is not wanted. Yellow corydalis has a mounding growth habit, reaching a maximum of around 15 inches tall, although it normally stays much smaller.
Light
Yellow corydalis is a shade-loving perennial, ideally grown in a location that receives part shade, or a maximum 6 of hours of direct light a day. While it can technically tolerate full sun, in extreme heat and sun conditions yellow corydalis may suffer from leaf burn.
Soil
Moist, well-drained soil is best for yellow corydalis, although it does tend to tolerate drier conditions better than other corydalis species. It appreciates alkaline soil (between 6.5 and 8). Yellow corydalis likes ordinary to humus-rich soil but can tolerate a wide range of soil types.
Water
Yellow corydalis needs consistently good moisture during the growing season in order to thrive. However, it does not tolerate wet soils during the winter when the plant is dormant. Water yellow corydalis regularly during the growing season and do not allow the soil to dry out. In the winter, cut back on any supplemental watering to avoid root rot or drowning the plant.
Temperature and Humidity
Hardy in zones 5 through 7, yellow corydalis is generally intolerant of extremely hot, humid temperatures. It prefers cooler climates with average humidity as it also doesn’t tolerate dry conditions well. In the British Isles where cooler temperatures with low humidity are the norm, yellow corydalis grows prolifically and is even considered to be a weed.
Fertilizer
Yellow corydalis does not require regular fertilization but does benefit from soil rich in humus and organic matter. While not necessary, fertilizing at the beginning of each growing season with a gentle organic fertilizer can help give the plant a boost. Alternatively, adding a shovel-full of compost or manure into the soil each year will help to provide yellow corydalis with the nutrients that it needs to thrive.
Growing from Seeds
While yellow corydalis self-seeds prolifically when grown outdoors, it is not as easily grown from seeds otherwise due to its complex dormancy requirements. However, it is also not easily divided or transplanted, so if you are looking to add yellow corydalis to your garden starting with seeds is the best option. To start yellow corydalis seeds indoors, sow seeds into moist potting medium and place the potted seeds in plastic bags at room temperature (approximately 70 degrees Fahrenheit) for about 5 to 6 weeks. Next, the seeds need to be cold-stratified and should be moved to near freezing conditions for 6 to 8 weeks. Last, the seeds should be moved back to slightly warmer conditions and kept at 50 to 60 degrees Fahrenheit until they germinate. Once the last frost has passed, plant young seedlings directly in the garden.
