When we think of crocuses, we imagine the first flowers of spring, daring the cold and snow to herald the coming change of seasons. And just as crocuses start the growing season, they can also be among the final flowers of fall. You may know them as Meadow Saffron or Naked Ladies (although that name also belongs to Amaryllis belladonna)—these goblet-shaped pink–to-purple flowers that spring leafless from the ground in early autumn. They don’t last long, only two or three weeks, but their presence when all else is fading makes them worth the effort.
To be fair, autumn crocuses (Colchicum sp., often C. autumnale) aren’t really crocuses. They’re among the lilies (family Liliaceae), not the irises (Iridaceae), and are not to be confused with true autumn-blooming crocuses, such as Crocus sativus (from which we get saffron).
Still, Colchicums look very much like spring crocuses and you grow them in much the same way. They’re best planted in late summer or early fall, and grow from corms, not bulbs. You bury them in the same way, however, two to four inches deep in amended, well-drained soil. They are happy in full sun to partial shade, but require some sun to open their flowers. Keep in mind that the flowers are easily crushed by wind or wayward footsteps, so plant them in a sheltered spot. Some supplemental irrigation may be needed to keep soil moist. The corms are hardy to zone 5; a thick mulch will provide some insurance in borderline areas.
In spring, the corms send up a few green, strap-like leaves but no flowers. Allow the foliage to grow—this is how the plants store up food for the year. Eventually, these leaves will fade and brown, and can be safely removed. Then, just when you’ve forgotten they’re there, the flowers emerge in showy clusters to add a final burst of beauty to the waning growing season.
Their warm violet color is beautifully set off by fall’s orange and russet hues—something to keep in mind when planting, as they are striking at the base of shrubs with bright fall foliage. Another option, since their own leaves are absent, is to plant them among a low-growing groundcover. Vinca minor, or Lamb’s Ears (as in the photo at top), are good options.
C. autumnale is the most popular species, and has a number of cultivars ranging from white to lilac pink, mauve, and violet. Some are bicolored, and ‘Waterlily’ (in the photos shown here) has double flowers. C. speciosum, C. byzantinum and C. agrippinum are three more similar species often found in cultivation. Look for them online, as garden centers rarely carry them.
If there’s one drawback to these flowers, it’s that all parts are poisonous. Their colchicine content keeps deer and rabbits away (but sadly not slugs and snails), but is a significant danger to dogs and children. Colchicine poisoning can be fatal, and there is no known antidote.