There are different strains and types of crocus. The
bloom early with the large flowered Dutch crocus blooming 10 days to 2
weeks later. Crocus likes a well drained gritty soil and a sunny location.
The flowers do not open properly in shade or partial shade. Where crocus
are naturalized in the lawn delay mowing until the crocus foliage has matured.
Crocus are planted in early September. The corms
are planted 3 to 4
inches apart and 3 inches deep. If planted too deep they fail to bloom.
Divide when foliage dies down. Remove dead and decayed corms. Replant
the corms again in September.
Scab causes pale yellow, water soaked lesions on the corms. The lesions turn brown or nearly black and are sunken with raised brittle margins.
A gummy exudate may be seen. Discard diseased corms and plant healthy corms
in a new area.
Dry rot causes lesions on the corms and leaf sheaths decay. Use a new
planting area each year.
Corm rot symptoms are water-soaked spots.
Bulb mites cause corm deterioration. The leaves turn yellow and the
flowers blast. Mites are yellowish white, slow moving, shiny, and bead-like.
Discard infested corms. Corms not showing root development may be dipped
in 122 degree water for a few minutes.
Tulip bulb aphid is waxy gray. It clusters under the bulb coats and
may infest the above ground plant parts.