Crocuses can reproduce asexually through the process of creating new, smaller cormlets around the original bulb each year. Over several years, these will form dense clusters that increase in number, allowing for larger, more impressive displays.
If the clumps become too crowded (every 3 to 4 years), one can lift and divide them in early summer after the foliage has died back to create new, separate plantings.
Crocuses can also reproduce sexually by pollination and seed production.