• In spring or late summer, plant iris rhizomes (modified stems) in a full sun location in fertile, well-drained soil.
Ensure that the upper surface of each rhizome is exposed to the sun (buried
rhizomes won’t flower). • To control iris borer, peel away leaves down to the rhizome in early spring to destroy any overwintering
eggs (do not compost). Destroy any rhizomes where
borer tunnelling is evident. • In Zones 3 and 4, rhizomes may be mulched with dry
straw, pine needles or horticultural sand for winter protection. Divide clumps every four years, five weeks