Tanya Ruffin, Gill, Daniel J.
Blooming from late March to early May, the Louisiana iris is a floral ambassador that has carried our state’s name all over the world. Louisiana iris is the name used worldwide for a unique group of native Louisiana iris species and their hybrids. Their extraordinary beauty and reliability in the garden have made them increasingly popular, but they still deserve more recognition and use here in their home territory
Though a number of iris species are native to
Louisiana, only five species, Iris brevicaulis, Iris fulva,
Iris giganticaerulea, Iris hexagona and Iris nelsonii are
known as “The Louisianans.” Only in south Louisiana
do all five species occur together. These five species
are closely related and will interbreed with each other
but with no other species. The crossing, or interbreeding, of these species has resulted in the modern
hybrid cultivars we grow today. Their large, attractive
flowers cover a broad range of colors, including many
shades of blue, purple, red, yellow, pink, gold, brown,
lavender, burgundy and white.
The best time to plant Louisiana irises is in August
and September when they are dormant, but you can
buy and plant them in spring while they are in bloom
with good success as well. When purchased and
planted in spring, however, Louisiana irises need to be
handled carefully to avoid damaging the foliage and
flower buds, and you may need to stake the plants
after planting to hold them upright after planting
(established Louisiana irises do not need staking).
Louisiana irises should be grown with as much direct
sun as possible. Although they will tolerate shade
for part of the day, at least about six hours of direct
sun are needed for good blooming. You can plant . You can plant
Louisiana irises in beds by themselves, combined with
other perennials or even in aquatic gardens.
When preparing a spot to plant them in a typical bed, incorporate a generous 3-inch layer of compost, rotted manure or peat moss and some general purpose fertilizer into the soil. These irises grow best in a soil high in fertility and organic matter.
Aquatic culture is one of the easiest and most natural ways to grow Louisiana irises and the foliage tends to stay more attractive in the summer. Simply place a potted iris into your decorative pond or aquatic garden so that the rim of the pot is a few inches below the water’s surface. Louisiana irises also grow well and look great planted in the ground on the edges of large ponds.
The large seedpods that form after flowering
should be removed as soon as you notice them to
keep the plants more attractive and vigorous. Next
fall, in October or November, fertilize the irises as they
begin their winter growing season.
The LSU AgCenter and the LSU College of Agriculture