Choosing desert plants depends on your caveats

A friend recently asked me about plants that he could install in a desert environment. Certainly, a large variety of plants could fill the bill, but he gave me a caveat — whatever plants I suggested would need to rely on naturally occurring water, not irrigation. That makes a world of difference in selecting the proper variety for this region.

It is possible to grow virtually any plant here in the beautiful Mojave, assuming that we are working with no limits on water, fertilizers, shelter or soil amendments. To put it another way, as long as we are willing to spend large amounts of both our money and precious resources, we can easily grow nearly any landscape plant. It would probably not be a surprise to learn that very few gardeners are willing to do so.

The plants that grow wild in the desert are tough and durable, but not all of them meet the traditional definition of "pretty." They rarely have a dense canopy of big green leaves, nor do most of them produce spectacular floral displays. This is not to say that there are not several plants with interesting leaves and attractive flowers.

Some of the biggest desert plants, such as mesquites, acacias and desert willows, are true trees, small to medium height, with slender leaves and lovely flowers. Blossoms of desert willows are similar to a few tiny orchids. The canopy of any desert tree provides dappled, not dense, shade. As desert natives, they will survive with relatively low inputs of water.

Yuccas and agaves are botanical cousins that are also desert natives. Although they can be spiky, neither is a cactus. Both of these genera are as remarkable for their structural interest as for their hardiness in the face of salty infertile soil, drought and extremely bright light. The leaves of each of these plants are similar: long and straplike, but they are not the same plants.

The most common yucca around is the Joshua tree (Yucca brevifolia), which is not a tree. Other varieties are available through nurseries that have a good selection of desert plants. We seldom grow them for their flowers, but when they do occasionally bloom, they are gorgeous. The flowers are white to cream colored, occasionally with magenta highlights. They appear in clusters of blossoms that can be several inches wide. How often they bloom, and in what month of the spring, depends on weather. A wetter winter may improve flowering, but a drier one might increase the size of the blossoms.

There are several species of agave that thrive in this, their home environment. The largest is Agave Americana, which is sometimes called "century plant." Despite the name, it rarely lives more than 30 years. Like other members of the genus, it will produce a striking inflorescence only once in its lifetime. This flower stalk can be more than 10 feet tall. The parent plant then dies, but usually it will be surrounded by "pups," small rosettes that will grow into new agaves.

Many shrubs have evolved in the desert Southwest. Having originated here, they are able to tolerate the challenging conditions one finds in this part of the world with only a little additional attention. Brittlebush (Encelia farinosa) is a naturally round shrub, so there is no need to hedge it into an unnatural ball. It grows up to about 5 feet tall and can produce wonderful sprays of golden yellow flowers in late winter to spring. Artemisia is a genus of several desert shrubs that perform very well under poor conditions. Artemesia caucasica, "silver spreader," is a cousin of sagebrush and wormwood, with interesting gray leaves and a unique, pleasant, aroma.

We tend to overlook smaller desert plants, but their leaves and flowers can be beautiful. Desert five spot (Eremalche rotundifolia) may be little, but it behaves like the true Mojave native plant it is. Drought, poor soils or extreme light and heat do not stop it from producing round leaves and cup-shaped flowers. As the name suggests, there are five spots on the inside of the cup at the base of the petals. Another low-growing plant that some people even use as a ground cover is cranesbill (Erodium reichardii). If there were ever a "sweet plant," this would be it. It does not grow much taller than 3 inches, with finely dissected leaves forming a clump that shows off its half-inch wide pink flowers.

Excess water and fertilizer can make these plants too tender to survive. Some species are native to this continent. Several of the hybrids are from other parts of the world where conditions are as challenging as the Mojave; hence they survive here.

Many plants can survive our conditions if we provide tender care. It takes a tough desert plant to survive without us.

Angela O'Callaghan is the Social Horticulture Specialist for University of Nevada Cooperative Extension. Contact ocallaghana@unce.unr.edu or 702-257-5581.