The biennial Corydalis species seem to be a lesser explored area of the genus, and are often spoken of in disparaging terms by some. Corydalis heterocarpa is a good example of why those people are wrong. Being a biennial, it forms a dense rosette of glaucous leaves in it’s first year. Despite looking too lush to be hardy, it has come through some vicious cold weather here with no trouble at all. In it’s second year it veritably explodes green and yellow: upwards and outwards with equal enthusiasm.
Like so many plants with a biennial life cycle, in nature it is an opportunist. It takes advantage of clearings and disturbed ground, completing it’s life cycle while conditions are favourable. Interestingly, in my garden it doesn’t seed around naturally. It grows very easily from seed (in pots or trays, before planting out), but has no inclination to self-seed.
Corydalis heterocarpa branches freely, so should you wish to tidy it up a little, deadheading and judicious pruning can be productive. To collect the seeds, you’ll need to allow it a little middle-age spread.
To explore further:
All in all, this a much overlooked plant. It is easy to grow, well behaved, and a very cheerful presence in any garden. It also bridges the gap between spring and summer flowering plants; a useful quality for any gardener.