Crocus poke their heads above the soil in early spring, before most other flower bulbs have awakened from winter slumber. These early spring flowers grow from a bulb, similar to tulips and daffodils. After flowering completes, the bulbs store energy and nutrients they receive via the roots and leaves to prepare for the next year's blooming period. They then sit dormant over summer and winter until the first breath of spring sets them to blooming once again.
Plant crocus bulbs in an area that receives full sunlight in early spring when the plant has foliage in place. Choose unobstructed areas or areas under deciduous trees and shrubs so that the light is not blocked during the bloom and leaf period of the bulb.
Water the bulbs in fall as needed to keep the soil moist but not soggy. While the bulbs appear dormant, the crocus is sending out new roots at this time. Stop watering when the ground begins to freeze, then resume irrigation in spring when foliage appears.
Lay a 3-inch layer of mulch over the garden bed once the ground begins to freeze in fall. Mulching protects the bulbs from temperature fluctuations, and also prevents frost heave in the soil, which can damage bulbs.
Fertilize crocus in spring when they first begin flowering with a fertilizer formulated for bulbs. Apply the fertilizer at the rate recommended on the package, but avoid getting it on the plants or the bulbs, as this can cause damage to them.
Leave the foliage in place until it has turned yellow and fallen over on its own. Cut off with clean shears at this point if desired. Removing the foliage prematurely can kill the crocus bulbs.