Louisiana ris are bog plants that can grow in boggy, wet or damp areas in the garden. Different varieties produce different colored flowers, and there are hundreds of varieties to choose from. Professional iris breeders are always producing Louisiana Iiris that bloom with different color combinations, and new varieties can be very expensive to buy. However, since they multiply readily, older varieties of Louisiana iris are available at a much lower cost and can be ordered through mail order catalogs or from searching the Internet and finding plant breeders in Louisiana. The active growing season is September through April, with blooms occurring in April.
Locate an area in the garden that remains damp and receives between 4 and 6 hours of direct sunlight each day. Louisiana Iris do not perform well in direct sun. If unable to plant right away, submerge the rhizomes in a bucket of water with the green parts of the plant remaining above the water. The rhizomes can remain in the water for up to a month before planting. However, to prevent the chance of rot, plant as soon as possible.
Plant the Louisiana Iris rhizomes in the planting bed after removing all weeds and enriching the soil with 2 to 3 inches of well-rotted compost. Plant the rhizomes 1/2 to 1 inch deep and about 12 inches apart. They can survive in average garden soil if the soil is kept constantly moist or in a boggy area with up to 6 inches of water. The best time to plant Louisiana Iris is in the fall.
Cover the area over and around the rhizomes with a 2- to 3-inch layer of mulch to preserve moisture. Fertilize with a balanced fertilizer, such as 13-13-13 or 8-8-8, in September and again in February. Do not fertilize during the winter. After the plants become dormant in May, continue to keep the area moist until new shoots appear in the fall.