
I tried growing Corydalis 'Blue Panda' once, but I think the plants only lasted a year or two. It wasn't until later that I learned that the blue-flowering varieties were notoriously fussy.
I just got word of a new introduction that is supposed to remedy that. This information is straight out of a press release, though, so take it with a grain of salt:
"This new variety from the Sichuan region of China is not only fast-growing and very floriferous from spring into fall, but it also tolerates any soil pH, thrives in sun or partial shade, and may even reseed. The tubular blooms begin in spring, appearing in shades of blue that can range from powder to violet, in clusters atop glaucous, finely-cut foliage that may remind you of Corydalis' cousin Dicentra. This plant is just a few inches high out of bloom, but when in flower can reach from 4 to 12 inches tall, and spreads about a foot wide. The blooms continue all summer and into early fall, keeping this low-grower very colorful. Superb for the border, as edging, in the woodland garden, or even in containers, 'Ex Dufu Temple' is a standout for color, vigor, and length of bloomtime. Give it well-drained soil of reasonably good fertility and let it go. It is cold-hardy and long-lived."