Prefers a moist to wet soil in sun or partial shade. Plants also grow on walls in the wild and so should tolerate drier conditions. This species is not hardy in the colder areas of the country, it tolerates temperatures down to between -5 and -10°c. It grows and spreads very well outdoors during the summer in most parts of the country and is very easy to increase by division. It can therefore be grown as a summer crop with divisions being taken during the growing season and overwintered in a greenhouse in case the outdoor plants are killed by winter cold.

Leaves - raw or cooked. Used in salads and in curries. Cooked as a vegetable. An aromatic flavor, we have found them to be rather overpowering in salads when used in any but small quantities.

Seed - sow spring in a greenhouse. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a greenhouse for their first winter. Plant them out in late spring or early summer of the following year, after the last expected frosts. Division is simple at any time in the growing season, though the spring is probably best. We find that it is best to pot up the divisions until they are rooting away well, though in selected mild gardens it should be possible to plant the divisions out directly into their permanent positions.

Old stone walls and rocky sunny places in lowland hills and especially by the coast in central and southern Japan. Shady, damp and wet places such as paddy fields, and in grass thickets.