While Louisiana Iris will tolerate moderately dry conditions for short periods of time, they should never be allowed to dry out completely. Upon being planted, young rhizomes need to be kept constantly moist for at least one week. Once established they will grow and bloom in a normal perennial bed or border. These Iris respond well to deep watering rather than a mere “sprinkling.” Drip irrigation can be very effective.
Louisiana Iris will always produce best if given lots of water. They will even grow and bloom in standing water. They are ideal for growing in pots sunken into fishponds.
Obviously, Iris growing in standing water will need more attention to feeding than ones planted in soil. The standing water can dissolve nutrients quickly, requiring more frequent feedings.
Given their preference for even moisture, Louisiana Iris respond well to being mulched. Mulching has the added advantage of regulating fluctuations in soil temperature, and it also protects the rhizomes (which often grow right at the top of the soil line) from the dreaded sunscald and the extreme temperatures. Importantly, good mulch will deter weeds from invading your growing area.
Many long time growers of Louisiana Iris use pine needles (known as “pine straw”) to mulch their beds. They are long lasting and do not mat down. Leaf mold makes great mulch. Avoid mulches of heavy woody material as it might take nitrogen from you soil during the decomposition process. Be forewarned that hay might make good mulch, but it usually contains weed seeds.
In hot climates Louisiana Iris rhizomes are subject to sunscald, a common problem which can result in poor bloom, rot, and other afflictions.