How to Propagate unusual iris?
Propagate by seed, or by division of rhizomes after flowering; for more advice, see dividing irises

unusual iris · Iris paradoxa
Grow in very well-drained soil, in full sun, and with the top surfaces of the rhizomes exposed so that they get baked in summer sun, which encourages flowering; best grown in a bulb frame or alpine house in containers using gritty, free-draining compost, and kept dry during late summer and winter
Propagate by seed, or by division of rhizomes after flowering; for more advice, see dividing irises