Quick Guide: summer, hardy, full sun, height: 60cm/24in, width: 15cm/6in

Bulbous irises are a small group which include the dwarf reticulated types ideal for rockeries and pot culture. For general garden cultivation hybrids of the xiphium group are best. These fall into three categories: Dutch irises are first to flower in early summer; the Spanish irises bloom about 2 weeks later, and finally the English irises 2 weeks later still. All come in a range of delectable colours, but the English group, while it bears flowers 12.Scm/Sin across, contains no yellows.

GROWING Plant the bulbs in autumn 10-15cm/4-6in deep, in light, fertile soil in the case of Dutch and Spanish hybrids. The English hybrids like rich, damp soil.

PROPAGATION Lift the bulbs after flowering. Detach the offsets and replant immediately, placing the smallest specimens in a nursery bed for a year.

VARIETIES Dutch: `Golden Harvest', vivid yellow; `National Velvet', deep purple, blotched orange. Spanish: `Frederika', white blotched yellow; `Blue River', aquamarine blotched orange. English: `Prince Albert', silvery blue; `Mirabeau', purple blotched white.

POSSIBLE PROBLEMS Narcissus fly larvae; grey bulb rot.