These flamboyant bulbs herald the approach of autumn.
Colchicums are the harbingers of change in the gardening calendar, erupting into life from late summer with clusters of vibrant pink or white blooms. The fact they flower from bare earth at this time without a leaf in sight has given rise to their common name of autumn crocus or naked ladies. But they are not related to crocus at all, in fact in different families. Our native autumn crocus C. autumnale, the only species native to Britain, has long been cultivated in British gardens. The other 150 species come from the Mediterranean, Asia, India and even South Africa, from which around 30 are more easily grown, with about 10 reliable varieties proving really popular.
Colchicims produce corms, rather than bulbs, much larger than those of crocus. They can be planted right up to the point buds appear as they will flower irrespective of whether they are in the ground or not, as many will have experienced after placing a corm on a windowsill as a child. All parts of the plant are poisonous, so handle them with care and wash your hands after handling the corms.
After their spectacular flowers have faded colchicums produce a rosette of surprisingly large glossy spear-shaped leaves in spring, lasting until early summer before dying down for the summer, before flowering again in early autumn. So take care where you place them as while they might look great in autumn, they might create a problem after leaves appear. Colchicum will grow in most moist, well-drained soil, but especially those which are chalky. They thrive in sun or dappled shade and are ideal for naturalising in short rough grassland around trees and shrubs. They also create seasonal impact in pots of loam-based compost. Plant the dry corms in summer when available, with the nose planted around 7.5cm (3in) deep and 15cm (6in) apart. If planted in grassland avoid mowing the area until June, when the foliage starts to fade. Slugs and snail can damage the blooms, so take precautions.