The Time of Year to Plant Crocus

Characteristics

• Short-stemmed crocus grow within 6 inches of the ground and have minimal, slender leaves. People often think that crocus grow from bulbs, but in reality they grow from corms. Corms are similar storage structures, but they do not form the typical bulb shape. Instead, they are underground storage stems. Crocus are found in most primary colors except red and produce cup-shaped blooms with thin, tender petals.

Spring-Blooming Crocus

• The majority of crocus are spring bloomers that flower between February and April, depending on the temperature and weather conditions of the area. Spring crocus must experience the cold temperatures of winter to break dormancy. Without this influence, the plant doesn't release the proper hormones for flowering. Dormancy prevents the plant from flowering at an inopportune time when it could be killed by harsh conditions. It regulates flowering and seed generation. Spring crocus must be planted in fall to experience the cold winter temperatures.

Fall-Blooming Crocus

• Fall-blooming crocus produce leaves after flowering. They require the slow warmth of a summer to stimulate the proper hormones that cause flowering. Both fall- and spring-blooming crocus are hardy plants that can be left in the ground year-round. This means once you have planted them, you will not have to dig them up to overwinter them in milder conditions. Fall-blooming crocus can be planted in spring until early summer. The foliage should be left in place even after the bloom fades to gather solar energy to store in the corms.

Planting Crocus Corms

• Crocus need to be planted 3 inches deep in well-drained soil where sunlight will penetrate at the time of blooming. Corms are spaced 3 to 4 inches apart and are planted individually or in clusters. Groups of crocus make the best displays and provide a clump of low-growing color. Crocus corms should be dug up every few years to divide. They produce offsets and spread into wider areas. Dig them up and cut apart the clumps to plant in separate locations. This increases blooms and provides you with more plants.