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Louisiana Iris Hybrids

by Barry Glick
by Barry Glick


Barry Glick has been involved in the plant world since 1954, when at the young, impressionable age of 5, he witnessed Don Herbert (Mr. Wizard on TV) put a cutting of a plant in a glass of water only to sprout roots a few shows later. Barry replicated the experiment with his one of his mother's prized Coleus plants, and as he watched the roots grow, knew that he was hooked for life.

Barry owns Sunshine Farm & Gardens in West Virginia - Zone 5

August 20, 2006

louisianairishybrids-m.jpg (27650 bytes)Louisiana Irises have to be one of the best kept secrets of the garden world. The word Louisiana conjures up images of steamy bayous and tropical foliage, but that's not the altogether correct image for these plants. Yes, most of the five species that make up this incredibly variable mix of plants do make their natural home way south of the Mason Dixon Line. But people are growing them in virtually every state of the union and most likely in every country in the world.

My first experience with this vibrantly colored, vigorous group of floriferous plants came over a decade ago as I was cruising a group of holding beds that I'd rarely visited higher up the mountain. These are beds that I "toss" plants into until a time that I can figure out where their final destination in the garden will be. I'm constantly rotating plants in and out of these beds and I've came up with a great many surprises. It was early Spring, and in the garden there were no Iris blooming. Much to my astonishment a huge clump of Iris appeared in one of the back beds that had gone previously unnoticed. There had to have been over 20 of the most lovely blue flowers with the most unusual look to them. At first I thought it was a Japanese Iris, but it was much too early in the season. I dug around and found a faded tag that said Louisiana Iris - D.K. Williams or Dorothy K Williams. I remember reading about this cultivar at the time, and the woman for whom it was named a long time ago, but for the life of me, I can't find any information about either now.

Plants termed "Louisiana Iris" are interspecific hybrids encompassing varying percentages of Iris nelsonii, Iris brevicaulis, Iris fulva, Iris giganticaerulea and Iris hexagona. Each one of these species brings a different range of color and form to the group. These are mainly "water Irises", but they do quite well in average garden soil. The wetter the soil, the more vigorous the growth. I've had equal success in shade or sun, but if you grow them in full sun, in most climates, they appreciate more moisture.

The term "Louisiana Iris" originated with a painting by famed naturalist James Audubon in the 1820's, but Tom Dillard tells the story so well that instead of paraphrasing him here, I'll just send you to and you can read his story for yourself.

Propagation couldn't be easier by division. The rhizomes resemble lobster tails and new plants grow from both sides of the front of the rhizome as it creeps along the ground. How slow or fast it creeps is determined mainly by soil moisture content. The sometimes fist sized seed heads yield handfuls of seed per plant. They are huge seeds and seem to germinate slowly over the period of a few years. Seedlings of open pollinated plants vary widely, but I've never experienced an "Ugly Duckling" in the lot. This group of plants has not yet succumbed to the insanity that the Daylily world has seen with hundreds of thousands of named cultivars. I certainly hope that it doesn't.

The popularity of this group of plants is most definitely on the rise, and if your interest has been piqued, you should think about joining the SLI, Society for Louisiana Iris. They have an extensive website at: I have a 225 page book titled "The Louisiana Iris", edited by Marie Cailett and Joseph Mertzweiller. It's an extremely well composed treatise on the subject and covers history, hybridization techniques, culture and propagation in great detail. It was published by The Texas Gardener Press in 1988 and from what I understand is unfortunately out of print. The Library of Congress number is 88-050001 and the ISBN number is 0-914641-09-3. A quick search at listed it as unavailable new, but used from $20.00. A real bargain! Texas Gardener Press can be reached at 254-772-8696, maybe with enough calls we could encourage them to do a reprint. Although I've never perused a copy, there's a new book published by Timber Press, which is an almost undeniable guarantee of its quality. You can buy this book at a substantial savings from the Society. Read the in depth description and purchasing information at -

Taxonomic Hierarchy

Kingdom Plantae - Plants
Subkingdom Tracheobionta - Vascular plants
Superdivision Spermatophyta - Seed plants
Division Magnoliophyta - Flowering plants
Class Liliopsida
Subclass Liliidae
Order Liliales
Family Iridaceae
Series Hexagonae
Genus Iris
Species several
Cultivar name Many
Common name - genus Iris
Common name - species "Louisiana Iris", "Gulf Coast Iris"
Synonyms Water Iris
Native range Missouri to Ohio, Mississippi drainage and Gulf coast to Florida and north to Carolinas
USDA Hardiness Zone Varies, but most to Zone 5, others to Zone 4 (3?)
Light preference Open bright shade to full sun
Soil fertility preference Average to rich
Soil pH preference 6 - 7
Soil moisture preference Average to moist to submerged
Bloom time May through June, depending on latitude
Bloom color The whole spectrum
Fragrance Slight
Foliage Medium green swordlike to thin grassy foliage
Spread Varies from mildly spreading to vigorous
Height 12" - 60"
Deer palatability Seems deerproof, at least my deer don't seem interested
Landscape uses Margin of ponds, mid sun or shade border
Related species Vaguely related to other North American species
Medicinal uses None found

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article and photo courtesy Sunshine Farm

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