Seed – this species is completely sterile and does not produce seed.
Division with care in the autumn once the leaves have died down. Replant immediately.
Bulb scales can be removed from the bulbs in early autumn. If they are kept in a warm dark place in a bag of moist peat, they will produce bulblets. These bulblets can be potted up and grown on in the greenhouse until they are large enough to plant out.
Bulbils – gather in late summer when they start to fall off the stems and pot up immediately. Grow on in a greenhouse until large enough to go outside. Plants can flower in three years from bulbils.
Prefers an open free-draining humus-rich loamy soil with its roots in the shade and its head in the sun. Prefers a lime-free soil according to some reports[28, 47, 143], whilst one says that it succeeds in a calcareous soil and another that it succeeds in ordinary garden soil[1, 42]. Prefers a deep acid loam. Likes a sunny position according to one report whilst others say that it is best grown in open woodland or amongst dwarf evergreen shrubs.
Stem rooting, the bulbs should be planted 15 – 20cm deep. Early to mid autumn is the best time to plant out the bulbs in cool temperate areas, in warmer areas they can be planted out as late as late autumn. Plants grow well in northern gardens in Britain.
A sterile triploid species, probably of hybrid origin.
A very ornamental plant, it is cultivated for its edible bulb in Japan[2, 42, 163].
This species tolerates virus infections, but it can transmit them to other species in this genus and so is best grown away from any of the other species.
The plant should be protected against rabbits and slugs in early spring. If the shoot tip is eaten out the bulb will not grow in that year and will lose vigour.