Louisiana irises can be divided and transplanted now through early October. This will keep them from overcrowding and keep them looking their best!
Unlike most perennials, Louisiana irises are at their most dormant stage in late summer, making now the ideal time to divide them. You will need to dig up a clump using a shovel or garden fork. Be careful not to damage the rhizomes!!! When replanting, the top of the rhizome should barely show above the soil surface. Mulch the bed about 2 inches deep and water thoroughly.
This also is a good time to plant new Louisiana irises. Louisiana irises grow best in a sunny location with adequate watering!