Ornamental grasses are in the news, cast as the villain of the piece. Two species are indeed a problem.
Buffelgrass (Pennisetum ciliare) has escaped cultivation and become a noxious weed that threatens our fragile desert ecosystem. One called fountain grass (Pennisetum setaceum) is also problematic, but not as prolific.
Meanwhile, some truly lovely (and noninvasive) grasses are overlooked by landscapers and homeowners alike when planning a landscape. And that's a real shame. Ornamental grasses are versatile, beautiful, and low care. They are also fast-growing, long-lived, and resistant to drought, pest and disease. From a design standpoint, they add color, texture, and movement to the landscape.
There are many ways to categorize ornamental grasses, but for now we will simply use size. Height and width are generally roughly equal. Most of the grasses on this list are native to the Sonoran or Chihuahuan deserts. By using natives, you use a plant that has already proven it can survive here without becoming invasive.
Large grasses reach over three feet. These can overwhelm a small yard, so only use if you have space. Three in the Muhlenbergia genus do well in our area. Pink muhly (Muhlenbergia capillaris) reaches around four feet, and has very delicate leaves which turn color and appear like a pink mist in fall. Bamboo muhly (Muhlenbergia dumosa), to six feet, grows in bamboo-like clumps, without invading the rest of your yard. Bull grass, or bull muhly (Muhlenbergia emerslyei) can reach five feet, and adds bold interest.
Three grasses at around three feet perform well. Cane beardgrass (Andropogon barbinodis), great for a meadow effect. Big galleta (Hilaria rigida), flowers February to September with fuzzy spikes. Japanese silver grass (Miscanthus sp.) has delicate leaves and bold seed heads. The last is not a native, but works well in the oasis zone of a xeriscape.
Medium-size grasses are around two feet tall. These are ideal for mass plantings for full effect. Purple threeawn (Aristida purpurea) is delicate, with graceful seed heads. Sideoats grama (Bouteloua curtipendula) is also delicate, with seeds that wave to the side, like a flag in a breeze. The blue grama (Bouteloua gracilis) has a bluish color to the leaves, and makes a lovely counterpoint to red granite mulch. Green sprangletop (Diplachne dubia), is hard to find but offers sprightly spangles of seeds. Ideal for the sandy soils that many of my readers have is the sand dropseed (Sporobolus cryptandrus), with seeds the birds enjoy.
Two medium-sized grasses from the American Great Plains grow well here with some irrigation. The plains lovegrass (Eragrostis intermedia), mounds and features delicate nodding seedheads from June into October. The plains bristlegrass (Setaria macrostachya) has a compact upright form.
Small grasses, under a foot high, add a settled look to the landscape. They look great on small slopes, or tucked in around decorative boulders. Indian ricegrass (Oryzopsis hymenoides) is graceful with delicate seedheads. Burro grass (Scleropogon brevifolius), forms tiny tufts, with curly leaves and rosy-silver floral parts. The alkali sacaton (Sporobolus airoides) is upright and perfect for heavy alkali soils.
Consider adding one or more of these glorious grasses to your landscape. Most of these are available at local nurseries or from High Country Gardens (highcountrygardens.com).
For the little water they need, ornamental grasses add so much to your yard; color, motion, sound, plus they are attract to native birds.
Jacqueline has been gardening in the Southwest since childhood. Dr. Soule has been writing articles about how to garden successfully in our area for over two decades. Look for her column in these pages every week.