How to Propagate Siberian iris 'Summer Sky'?
Propagate by division of rhizomes from midsummer to early autumn

Siberian iris 'Summer Sky' · Iris 'Summer Sky'
Grow in any good garden soil that is preferably moist but not waterlogged. In drier soils, dig in well-rotted organic matter before planting then apply as a mulch each spring
Propagate by division of rhizomes from midsummer to early autumn