Native over a tremendously wide range of the southeastern United States, Iris cristata is tough and has nobility in its diminutive size. Growing low to the ground and gradually spreading, the lovely flowers welcome spring for those who look for detail in the garden.
Iris cristata is a good choice in gardens that have perhaps the most difficult growing challenge of all: dry shade. This stated, if you grow Iris cristata in full sun, soil should be consistently moist. Spread is slow but steady and Iris cristata may be grown as a ground cover.
My favorite use however is small pockets of Iris cristata in unexpected places. The photograph below is of a very small patch of Iris cristata peaking from beneath a fence, flowering for a brief period every year before receding to be rediscovered next season.