Good gardeners know that the world of bulbs doesn't begin and end with daffodils and tulips in spring. Bulbs also bloom in fall and some of them are strutting their stuff right now. Those above are called autumn crocus and are so eager to bloom, they'll do it whether you plant them or not.
Not to confuse you, but there are actually two groups of plants called autumn crocus. The ones you see above aren't really crocus at all, but species and selections of Colchicum, also known as meadow saffron. Telling them apart from true fall-blooming crocuses is easy. The flowers of Colchicum are bigger and showier. Plus, the lush leaves that pop up in spring and die down in summer don't look anything like the small, spear-shaped leaves of true crocus.
Not For Human Consumption A chemical derived from Colchicum, called colchicine, has a long history of use in folk medicine. Until recently, you could buy it in over-the-counter supplements to treat gout. Trouble is, colchicine is very toxic and overdosing could quickly kill you. So don't chow down on autumn crocus. Don't let its poisonous potential prevent you from planting it, though. Guess what other bulb will kill you if you eat it? The daffodil.
Colchicine is very useful to plant breeders, because its application causes plants such as daylilies to double their number of chromosomes. This produces hardier, faster-growing plants with larger, showier blooms of greater substance. When you see a huge, ruffled daylily bloom, colchicine was likely involved.
How to Grow Plant autumn crocus bulbs (actually corms) in late summer and early fall in loose, well-drained soil in a full to partly sunny site. Plant 3-4 inches deep and 6-8 inches apart. Don't worry about rodents eating them. Leave them in place and they'll gradually multiply to form drifts. If you prefer an indoor show, set the corms on a pebble-lined dish filled with water or atop a bulb-forcing vase. Flowers will sprout right from the corms. After the flowers fade, plant the corms outside.