A couple of weeks ago I wrote about the principles of xeriscaping: start with a plan, improve the soil, choose the right plants, limit lawn, use mulch, irrigate efficiently and maintain the landscape. Appropriate plants are those that hold and conserve water. Water-efficient plants make a xeriscape successful.
What makes one plant more water thrifty than another? First, they are adapted to the climate and can thrive in intense sun with drying winds. They can survive periods of reduced water availability that may last days, months or years. Some plants avoid water stress and some tolerate it. Plants with wide-spreading or deep root systems can absorb water from a larger area giving them an advantage over shallow rooted plants. Drought-tolerant plants extract water from soil efficiently with less stress to the plant. Gray-leafed plants can reduce water lost from leaves because they reduce the amount of sunlight absorbed. The hairs on fuzzy-leafed plants shade the surface of the leaf lowering water need. Smaller leaves lose less water through transpiration (water loss) than larger leaves. Fewer leaves on the entire plant reduce water lost through evaporation/transpiration. Thicker leaves can be another water-efficiency adaptation. To avoid drought, some plants only produce leaves when there is enough water, going dormant under drought conditions. Low-growing plants avoid drying winds. There are also chemical and cellular adaptations that help plants survive drought. Plants with any of these adaptations can actually be stressed when given too much water or fertilizer.
Before you choose plants for a xeriscape design, find out if they will thrive in the microclimate you want to plant in. Know the culture requirements of the plant such as light, moisture and soil. Do you want trees, shrubs, flowers, ornamental grasses or groundcovers? Water-thrifty plants come in all shapes, sizes and colors.
Know that all plants need water to establish. As a suitable water-efficient plant matures, it should require less water. Species native to climates, latitudes and annual precipitation rates similar to ours can work well as can some native plants. Choose tenacious plants that require the same amount or less rainfall as this area receives annually, about seven to 11 inches. For maximum watering efficiency, keep plants with similar water requirements together rather than mixing plants with high- or low-watering needs.
Put the right plant in the right place for a successful water-efficient landscape. For more information and photos of specific plants, see “Choosing the Right Plants for Northern Nevada’s High Fire Hazard Areas: http://www.unce.unr.edu/publications/files/nr/2007/eb0701.pdf.