Spring-flowering bulbs, such as tulips and daffodils, are familiar to all gardeners. Though not widely planted, the attractive flowers and unique life cycle of the autumn crocus or colchicum make it a welcome addition to the garden.
Autumn crocus (Colchicum autumnale) is also known as meadow saffron, mysteria, or naked boys. It produces pink to lavender crocus-like flowers in the fall. The flowers arise directly from the corm. There is no foliage present when the plants are in bloom. The dark green leaves (approximately 1 to 2 inches wide and 10 to 12 inches long) emerge in the spring, remain until summer, then turn yellow and die to the ground. After which, the flowers magically appear in the fall.
Colchicums should be planted immediately after delivery in August or September. (They often bloom in their shipping container if not planted immediately.) Plant the corms in well- drained soils in full sun to partial shade. Good planting sites include naturalized areas under the filtered shade of large trees and shrubs, in rock gardens, or among low-growing groundcovers such as sedum. For the best visual display, plant colchicums in clumps. The corms should be planted 2 to 3 inches deep and 6 inches apart.
Gardeners can choose from several excellent cultivars. Colchicum autumnale 'Album' produces pure white flowers. 'Alboplenum' has double, white flowers. The flowers of 'The Giant' are 10 to 12 inches tall and violet with a white throat. 'Lilac Wonder' bears large, rosy- purple flowers. 'Waterlily' produces double, lilac-pink flowers which resemble a water lily. Colchicum autumnale and the aforementioned cultivars are hardy in USDA Hardiness Zone 5.
Colchicums are native to Europe and northern Africa. The scientific name comes from Colchis, an ancient country bordering on the Black Sea, now part of the Georgian Republic, where colchicums are abundant.
The dried corms and seeds of colchicums are the source of medicinal colchicum. It is also the source of colchicine which is used in plant breeding to induce polyploids.
This article originally appeared in the July 28, 2000 issue, p. 99.