Colchicums should be planted immediately after delivery in August or September. 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.
Alboplenum' has double, white 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.