Plant of the Month April 2009

Latin name: Iris spuria
Common name: Spuria iris
Plant type: Perennial
Blooming season: Late spring
Flowers: Available in all colors
Foliage: Slender, typical, upright iris foliage
Mature height: 3-5 ft., depending on cultivar
Spacing: 3 ft.
Hardiness: Zone 5
Soil: Well-drained
Exposure: Full sun
Water usage: Low
Sources: Mail order 

I’m going to share with you one of my favorite garden perennials, spuria iris. All across the South this tough-as-iron plant flowers in abandoned lots and around old houses, but we ignore it for its showier relative, the bearded iris. Personally, I think it’s time to invite this graceful and tough plant back into our gardens. 

Spuria iris flowers resemble bulbous Dutch iris and Louisiana iris more than their bearded brethren. Originating from the Mediterranean area of Europe, they prefer areas where the summer months are dry. Sounds like Texas to me! The most common variety of spuria iris you will come across is the old Iris spuria sp. ochroleuca, which is sometimes called the oriental iris. Its flowers of pure white are of the usual iris arrangement -- three petals up and three down. The three flags, or upper petals, are pure white, and the lower petals are splashed with yellow. But if white and yellow aren’t your thing, don’t worry, hybridizers have been busy as bees making new colors in every conceivable combination. I’ve banned myself from looking on the Internet for them, because every time I do, I end up buying more than I can afford! 

Spuria irises bloom about two weeks after bearded irises, on stalks that can reach 5 feet tall, depending on the variety. Spuria aren’t choosy about soil pH or soil type; I’ve seen them growing in sandy East Texas soil and in Blackland clay. One of the most incredible things about this iris is that it will grow well in partial shade. Here in Texas they will sprout growth in late fall or mid-winter, then grow through the spring flowering period, and quite often go dormant at the hottest part of the summer. Nothing like a plant that knows to take a siesta during the toughest of times!

Spuria irises take a year or so to get established, but after that, you will have them forever. You most likely won’t find them for sale at any nursery, so use Google and type Spuria Iris into the web browser. You’ll find several different mail order companies that carry them. My favorite link is http://www.comancheacresiris.com/.

When you receive the irises, make sure to plant them quickly. They hate for their roots to dry out. If you have an existing clump and want to divide it, do it in the fall when the leaves first start to emerge. Just be warned their roots are a lot like cutting piano wires. Once established, this plant isn’t an easy one to dig up. Spurias also dislike being transplanted, so do it as little as possible. Make sure when first planting not to plant them too close together. I recommend at least 3 feet apart. Plant spurias in the part of the garden where you won’t run the irrigation three times per week. This plant is perfectly tough enough to live on rainfall alone after the first year of establishment. The easiest way to kill spurias is to mulch them heavily and overwater them during the heat of summer. Remember they like to go dormant, so don’t panic when the leaves start to turn brown, and especially don’t start running more water around them. Just let them dry up and go to sleep.

We Texans are lucky that we can grow spuria, bearded, and Louisiana iris all in our gardens.  Each has its own requirements and niche to fill in any garden. Personally, I have all three in mine, so I have weeks of irises to cut and bring inside. I hope you’ll bring some home to try in your garden, too.

About the author: Jimmy Turner is the senior director of gardens at the Dallas Arboretum. Visit http://www.dallasplanttrials.org/ for more information on his trials

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