How to Propagate iris 'Dusky Challenger'?
Propagate by division of rhizomes after flowering, from midsummer to late summer; for more advice, see dividing irises

iris 'Dusky Challenger' · Iris 'Dusky Challenger'
Grow in well-drained, fertile, neutral to slightly acid loam in full sun; sun on the rhizome encourages flowering. See also bearded iris cultivation
Propagate by division of rhizomes after flowering, from midsummer to late summer; for more advice, see dividing irises