When to Plant Crocus
You should purchase your crocus bulbs in September or October but wait to plant them until soil temperatures are below 60 degrees F. (16 C.). As a general rule, crocus bulbs are planted in November. The crocus plant is hardy to USDA zones 3 to 8 but planting times will vary slightly depending when you receive your first freeze. The crocus bulbs should be in the ground before the first frost. Crocus need a chilling period of 12 to 16 weeks before blooming, so plan accordingly when growing crocus in your garden.
How to Plant Crocus
Crocus bulbs need well drained soil in a sunny to partially sunny location. They thrive in a soil pH of 6 to 7 and are tolerant of a wide range of soils. You may even grow crocus in the lawn but be careful as they will naturalize and spread to become a potential nuisance. Plant the crocus bulbs in groups in the garden bed for impact or even under trees, as they need little root space. Bulbs are planted 3 inches (8 cm.) deep and 3 to 4 inches (8-10 cm.) apart. Provide mulch over the planting area in very cold zones but rake it away in early spring so the flowers can emerge. Gardeners in zones where the winters are too harsh or too warm to plant in fall can force the crocus bulbs indoors in time for a spring planting.
Crocus Flower Care
Animals can be a big problem with crocus bulbs. Squirrels and other rodents will dig up the bulbs and eat them, and deer will graze on the early foliage. You can cover the spring bulb bed with wire mesh to prevent squirrel damage, and there are deer repellents you can try to prevent their feeding on your flowers. When the flowers are spent, leave the foliage until it dies back to collect solar energy to feed the bulbs for the next bloom. Every two to three years, crocus clumps should be divided in fall when they are dormant. Dig up the clump and cut it into pieces with several bulbs attached and at least four healthy stems. Fertilize crocus beds with a slow release fertilizer in fall according to the manufacturer’s instructions.
Choosing Crocus Varieties
Crocus are low growing plants that fit best into the front of a color display or even in pots. There are over 80 known crocus species with approximately 30 in common cultivation. The usual colors found are white, mauve, lavender, yellow, and even striped. It is best to shop early for the best selection of unique varieties like Zwananburg Bronze, a yellow flower with a bronze exterior. Consider the specific hardiness range of the bulbs, as some are more tolerant of cold than other types.