Common Crocus Crocus

Crocus is a genus comprising about 90 species of perennial, early spring blooming corms. The flowers bloom in early spring, typically closing at night or on cloudy days and opening up with the morning sun, with many popular hybrids available. The plant foliage, basal, grass-like leaves with a central white stripe, turns yellow as plants go dormant several weeks after bloom. The plant is often used in rock gardens, beds, ground covers, lawns, and woodland gardens. It tolerates drought, but you should keep it moist during the growing season.

Crocus prefer full sun to partial shade and gritty, well-drained soil, sandy loam with composted organic matter. It will not grow in full shade. Avoid heavy clay. To plant from corms, plant in the fall about 2.5 inches deep and 2 inches apart, 35 to 70 corms per square foot. Plan to divide the corms about every 4 years. Note that plants are injured at temperatures below 14 degrees F (-10 degrees C).

Yellow-flowered crocuses and smaller sized crocuses belong to other species, but all have ephemeral flowers which last about a day before drying and withering. Crocus flower colors vary enormously, although lilac, mauve, yellow, and white are the most common. Keep the foliage intact for about 6 weeks after blooms, as the leaves generating food for next year's floral production. 

Diseases, Insects, and Other Plant Problems:

Crocus are susceptible to numerous pest and disease problems, including small mammals. Squirrels seem particularly adept at locating, digging up, and eating newly planted corms.

VIDEO Created by Elisabeth Meyer for "Edibles, Bulbs, and Houseplants" a plant identification course offered in partnership with Longwood Gardens.