Crocus bulbs normally bloom outdoors with purple, white or yellow flowers during the spring, but improper care or the wrong growing conditions can cause them to fail to bloom. Gardeners can take several measures to help crocuses bloom.
The wrong planting environment can cause crocuses to fail to bloom, including growing conditions with poor soil fertility or lots of shade. Gardeners should plant crocuses in a sunny garden space during the fall; the flowers should bloom in the spring. Add a few inches of compost to gardens with poor soil fertility or poor drainage to help crocuses bloom.
Gardeners who store crocus bulbs in between plantings must make sure that the bulbs receive a chilling period of at least 8 weeks of temperatures between 1.67 and 4.44 degrees Celsius. Crocuses planted outdoors in the fall receive this chilling period naturally during the winter, but gardeners planting indoor bulbs must artificially provide this chilling period in the refrigerator.
To ensure that bulbs bloom, protect them from rodents outdoors, water them after planting, buy healthy-looking bulbs from a reputable source and plant them at depths of around twice their height. Protect bulbs from rodents by placing wire mesh over them until they start to shoot up during the spring.