By ANGELA O’CALLAGHAN
As almost everyone around the Southwestern region knows, living in the desert means that water must not be wasted. With the drought in the west continuing to be a major problem, there is certainly no water to spare. Historically, the worst of the water wasting offenders have generally been residential landscapes, especially where sprinklers spew water on sidewalks and roads while irrigating lawns.
In order to minimize waste, many Southern Nevada residents have removed turf grass from their yards. One title for this is called “Xeriscape”, which means dry landscaping. There are, unfortunately, some people who have yet to overcome their belief that xeriscape is zero-scape, shuddering at the thought that without a lawn, their yards would look like the side of a new highway – a flat panorama of red or grey rocks. This is one very good reason for the newer term “Water Smart Landscaping”.
People have often changed their minds about removing turf when they discovered the beauties of desert landscaping, and now incorporate dramatic cacti, yuccas and agaves in their yards. Trees provide visual interest, shade and sometimes flowers, like the vivid yellow mesquite flowers or orchid colored flowers of desert willow.
All these plants have evolved to survive the challenging conditions of the Mojave, or whatever their desert of origin. They can withstand daytime temperatures well into the three digits, and the cold nights where temperatures have been known to drop down into the teens, or below. If they have leaves at all, these are either very small, or have a thick waxy coating, or attach to the plant at an angle that actually avoids direct sunlight. True cacti have lost their leaves entirely. Some desert trees have roots that can “mine” for water deep into the soil. These survival tactics are critical in the wild.
We exploit those tactics when we create desert landscapes around our homes. The conditions we provide are not necessarily any less severe than what can be found out in the desert. The soil around many houses in the valley may not even be as fertile as desert soil. It may seem peculiar, but the soil of the desert plants in the yard needs a little improvement with compost or other soil amendment.
Because these plants originated in an environment where there is so little rainfall, it is a common misconception that we do not need to provide supplemental water. This is an unfortunate mistake, because nothing survives without water. Desert plants are certainly not equipped to deal with a large amount of water at any one time, but they definitely need to receive some, occasionally. Most of those we use should be on an irrigation system. When temperatures are at or above 100°F, these plants run the risk of dehydration. When the pads of a prickly pear begin to look shriveled, or even worse, topple over, it is clear that the plant is suffering from a lack of water. Fortunately, they tend to be very forgiving, and will perk up if they receive a healthy hand watering.
Dr. Angela O’Callaghan is the Social Horticulture Specialist for Clark County Cooperative Extension. Contact ocallaghana@unce.unr.edu or 702-257-5581.
