Tips On Growing Irises in the Desert | Gardening in the Desert |
a bunch of white and yellow irises all together

I’ll admit I have not always been an enthusiast of irises, including everyone’s favorite bearded irises. In my view, their bloom cycle is short and they spend most of the year as just green leaves — admittedly green leaves that add drama to a garden — but just leaves. Despite artists’ love of this flower from Tiffany to Monet to van Gogh, I have not easily embraced this perennial rhizome for my garden.

On the other hand, when the irises bloom in mid-spring, I reassess my garden to look for a space to plant irises that bloom in a rainbow of colors on sturdy upright stems. Irises offer much more than just lovely flowers for the garden. Their sweet violet scent is enticing. They attract butterflies and hummingbirds, and they make spectacular cut flowers.

Finally, irises are tough, tough, tough. They are deer and rabbit resistant, drought tolerant, sun loving and — did I say? — tough. I once read an article that proposed planting irises near the driveway where cars might drive over a planting because irises are tough enough to survive a few rollovers. Depending on the variety, they thrive in beds, borders, containers, naturalized areas, or in butterfly, cutting, and cottage gardens. Plus, these gnarly rhizomes make a beautiful and functional planting for erosion control on steep or difficult slopes.

close up of a purple and white iris freshly blooming.

While there are hundreds of species in the genus Iris, the most commonly planted is the tall bearded iris (Iris germanica). The distinctive six-petaled flowers have three outer hanging petals called “falls” and three inner upright petals called “standards.” Bearded iris plants range from three inches for the shortest dwarf iris to four feet for the tallest bearded iris.

Obviously, irises are not native Southwest desert plants even though they are planted in many gardens in our region. For those who cannot resist the flower and its perfume, it can be grown successfully in the desert by following a few guidelines.

First, select a sunny location because these plants need at least six hours of sun per day to bloom prolifically. Prepare their bed with lots of organic matter. Irises prefer fertile, neutral-to-slightly-acidic soil, which is not the usual garden soil in Doña Ana County. Our soil is low in organic matter and high in alkalinity. Therefore, to succeed with irises, we must amend the soil. Add several inches of compost when preparing a bed for the rhizomes. The addition of gypsum, biosolids, or bone meal also will help improve the soil. If your garden is clay or caliche, the irises may require raised beds to help drainage.

Don’t crowd iris rhizomes. Plant irises in the spring from nursery pots at least 16 to 18 inches apart to give them room to breathe, as they need good air circulation and room to multiply. Bare root plants can be planted in the spring or fall.

In spring, apply a low-nitrogen/high-phosphorus fertilizer or a balanced fertilizer around the rhizomes to encourage blooms. Don’t overdo nitrogen fertilizer, as that will encourage foliage at the expense of blooms. Many local irisarians prefer Carl Pool’s BR-61 because of its high phosphorus content and easy application. For a more organic approach, irises can be fertilized with biosolids or bone meal.

Water iris rhizomes as needed, depending on the season and temperatures. Since irises are drought tolerant, water them when the top two inches of the soil feels dry. Overwatering irises can cause the rhizomes to rot. Irises do not tolerate wet soil in wintertime, which is rarely a problem in our desert winters. Garden lore says irises prefer “wet feet, but dry knees.”

Irises require maintenance during the blooming season and also in the fall. Taller irises may need staking or they will fall over in our strong spring winds. Gardeners should remove spent blooms along the stems. After blooming is finished, flower stems should be cut down to the base. If any of the blooms form seed pods, these pods should be removed to reserve the plant’s energy and prevent too many seedlings from sprouting and crowding the rhizome.

In fall, prune back foliage to six inches from the ground. This will reduce the chances of overwintering pests and diseases, although irises have few pests or diseases in our dry climate. However, like many perennials, they may attract whiteflies, thrips, and aphids. Most of our gardens are too dry to support slugs and snails, though those pests will attack the leaves if they are in your garden.

Every three to five years, iris rhizomes should be divided and replanted in late summer to prevent crowding. The divisions can be planted to create new beds, fill in empty spaces, or shared with friends and neighbors.

With proper planting, fertilizing, watering, and timely maintenance, bearded irises should bloom bountifully. However, if your irises are not blooming, these may be the likely culprits: too little sunlight, too much fertilizer, rhizomes planted too deeply, or crowded plants that require dividing. Address these issues and you’ll soon have lovely flowers for the garden and vase.

two gorgeous yellow and maroon colored irises with texture.

If you wish to bring the colorful and perfumed blooms indoors, plan to cut the flowers in the early morning. Cut the stems when the flower buds are just beginning to open and submerge the cut ends in lukewarm water. When arranging in a vase, recut the stems at an angle. Pinch off spent flowers and refill the vase as needed.

Those of us with pets and livestock should be aware that irises are toxic to dogs, cats, and horses — particularly if they eat the rhizome. I’ve never known of any of these domestic animals being harmed by irises in a garden; still, a gardener should be aware of a plant that could cause harm to the family pets.

With spring around the corner, now is a good time to visit local nurseries and commercial gardens that specialize in selling iris rhizomes. Visit iris flower shows to discover specific colors and varieties that you like for purchase in the fall. Provide this rewarding plant with its needs, then sit back to enjoy the spring show year after year.

The Mesilla Valley Iris Society is celebrating its 50th anniversary and the 100th anniversary of the American Iris Society during the American Iris Society National Convention being held April 11 – 16 at Hotel Encanto in Las Cruces. The late registration deadline for the convention is March 15.

This is the first convention of the American Iris Society held in New Mexico and the Mesilla Valley Iris Society is organizing and hosting this event. The convention initially was scheduled for 2021 but then delayed to 2022 due to the pandemic. In preparation for 2021, iris rhizomes were planted in numerous local display gardens, so they have matured and will provide an excellent display for the 2022 convention.

The convention also features two days of bus tours to six private, public, and commercial gardens. If space allows after registration, seats may be available for those interested in seeing the gardens. Contact Howard Dash, conference chair and American Iris Society board member, at 575-652-7550 for more information.

To register or for more information about the convention or the gardens, visit the American Iris Society website.


Written by Jackey Meinecke

Photography by Cheryl Fallstead

Originally published in Neighbors magazine.

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