Desert Gardening

Flower & Garden Magazine, July, 2000 by Mikel Weaver

The desert--hot, scorched, unforgiving. T.S. Elliot called it "an old man in a dry season." Is it possible, then, that anything can grow in these wastelands we call the Southwest? With a little planning and creativity, the desert garden can be as vivid, functional and perhaps even more Fascinating than any other!

* THE UNUSUAL COMPLICATIONS AND REWARDS OF DESERT GARDENING

Extreme weather is the most common difficulty faced by desert gardeners. In some areas it is not uncommon for temperatures to soar well over one hundred degrees in the hottest months, while rainfall amounts may be as little as a few inches per year. Intense heat and sunlight dominate the summers, while in many regions very cold temperatures and even snow blanket the winters. Long, hot days followed by cool nights, and dry conditions most of the year followed by torrential rains, tend to exhaust plants not acclimated to these conditions. While the harmful effects of the desert's tough weather can't be missed, the benefits of this unusual atmosphere shouldn't be overlooked. An unusually long growing season is followed by a relatively short winter by most comparisons. The hot, dry stretch of early to midsummer is generally the most difficult season in gardening terms but can be overcome with a little ingenuity.

Growing plants under some type of roof cover, such as a terrace or arbor, will provide protection. Choosing only plants that do well in hot, arid climates is another sure way to increase the success rate in your garden. Joining a gardening group or web ring that specializes in desert gardening will provide additional resources for specific problems.

Water, or lack of it, is another obstacle desert gardeners face. In addition to the absence of rainfall in most areas of the desert southwest, evaporation factors, like gusting winds and low humidity, can be drastic. Vital moisture in desert plants is often evaporated faster than the plants ability to replace it. This, coupled with heat factors, often causes heat exposure, which is characterized by weak, wilting or shriveling plants.

Proper watering techniques can combat the naturally arid conditions of the desert, when necessary. Many plants that are naturally adapted to the desert don't need very much water, for example, cactus and most succulents. The hidden benefit of planting desert-hardy vegetation is that most are very water-provident and need little care.

Find the specific requirements of the plants you are working with and stick to them. Typically, less water is required during cooler months, when the plants are resting. When watering desert plants, a favorable moisture/air balance should be maintained, which is necessary for the plants to breathe. Don't water too often, and generally allow plants to dry out between waterings.

Spraying, misting or watering plants should be done only when the plants are cool and when temperatures are lower, usually early morning. The shock of watering or misting a hot plant can cause foliage burn or leaf drop. Many desert plants, such as palms and cacti, generally don't need misting, and their surfaces should be kept dry outside of natural rainfall to avoid surface rot.

The deserts of the southwest are notorious for their poor soil. High alkalinity, salt, clay, rock and sandstone are typical finds in desert backyards. The soil tends to be heavy, sometimes doesn't drain well and provides little nourishment. Naturally-occurring salt is probably the most common problem faced by desert gardeners. The salt in soil dissolves in water (which in desert areas also often contains naturally-occurring salt); it is then absorbed by the plant, where it accumulates in the soil, and is obvious as white, brown or black deposits on the soils surface. Fortunately, it is fairly easy to improve the quality of soil in your planting area. If you are planting directly in the ground and have poor soil, dig out the area and replace it with a good mixture of sandy, loamy soil that drains well. Use the same mixture when container gardening as well. In addition, deep, penetrating waterings help keep soil salts washed downward out of the root area.

Wildlife can be a nuisance in desert gardens. Because of the scarcity of water and succulent vegetation in the desert, rural gardeners often find everything from skunks to javelina to coyotes nibbling at their crops. Gila monsters, rattlesnakes and other reptiles will be drawn to water in gardens, especially during the dry summer months. Keeping a good fence in place and using reflective deterrents (such as hanging aluminum pie plates or old CDs) can be helpful. Prompt harvesting of fruit will also cut down on scavengers.

Less obvious pests, though harder to spot, can be just as devastating. Phymatotrichum root rot, also known as Texas root rot, is a disease of woody, Dictyledonous plants, including perennial ornamentals, vines, shrubs and trees, caused by a soil-born fungus that affects over 2,300 species of unrelated plants. Its occurrence is only in the alkaline, low-organic matter soils of the southwest United States.