These are not what you need if you are looking for something really showy but they really cannot be beaten for their subtlety and delicateness. The foliage is generally fine and feathery while the flowers are small, held above the foliage on slender stems. Each flower has 4 petals, 2 with long ‘tails’ and curved tips, while the other 2 petals are smaller and curve inwards. The result is a very delicate looking plant, which makes very well-behaved ground cover in semi-shade.
How to plant Corydalis:
Plant in a rich, well-drained site in partial shade - under deciduous trees is ideal. They will tolerate full sun if the soil doesn't dry out. Techincally not a bulb, but a tuber - plant in autumn at a depth of about 5cm. Add plenty of organic matter (homemade compost or leaf mould is ideal) to the soil before planting to ensure that happy medium of moisture-retentive but not waterlogged. A neutral soil is best, although they will tolerate slightly acidic or aklaline soils too.