A xeriscape is a landscaped area specifically designed to withstand drought conditions and reduce water consumption. The term was developed by Denver Water in 1981 by joining xeros, the Greek word for dry, with landscape. (It should not be confused with zeroscaping, which uses lots of rocks and only a few plants to create a landscape that requires little water.) Xeriscapes use native and water-efficient plants and then groups these plants together based on their water needs so they can be watered efficiently.
Arid, Transition, and Oasis Zones
The practice of xeriscaping varies from region to region. However, basic principles are generally followed no matter where you live. The first thing you will need to decide is if you want to adjust your existing landscape to be more conservative with water or design and construct an entirely new landscape. Either way, you should analyze your yard and decide what areas will become arid zones, transition zones, and oasis zones. The three types of zones allow you to group plants together that have the same water requirements.
Arid zones should be farthest away from the house and high-traffic areas. An arid zone will either be left in its natural state or planted with native and drought-tolerant plants. Transition zones will combine the drier areas with the more lush zones of your yard. This zone will take advantage of low and moderate water use plantings that need infrequent supplemental watering. Oasis zones should be nearer to the house where they can take advantage of rainfall runoff from the roofline and gutter downspouts.
Xeriscape Grass Options
Most people think that converting a yard to xeriscape means that you have to get rid of all your grass. This is not true. When you xeriscape, you reduce the amount of grass in your yard to only what you need and use. For areas where you want or need grass, you have two choices. Warm season grasses such as buffalo grass and blue grama are very water-conservative, but not very hardy under foot traffic. These grasses do not need as much water and are perfect in areas that do not get a lot of use, such as a sunny front lawn. Cool season grasses, like Kentucky bluegrass, are much more tolerant to foot traffic, but require more water to stay green. Use cool season grasses in areas where your children or pets frequently play.
Reducing the overall amount of grass you have in your yard is also important. If you have heavily shaded areas, consider planting shade-tolerant groundcover such as vinca or sweet woodruff in that area instead of grass. Replacing grassy areas such as steep slopes or the area between the sidewalk and the street with drought-hardy groundcovers or low-water perennials will not only save water, but eliminate troublesome mowing areas.
Drip Irrigation Installation
For areas of your yard that will require watering, it's best to install a drip irrigation system. Drip irrigation delivers water slowly at or near the surface of the soil. It can reduce water consumption by as much as 60 percent when compared to sprinkler systems because it minimizes the quantity of water lost to runoff, wind, and evaporation. You can purchase installation kits for drip irrigation systems online or at most nurseries and garden centers.
Soil Care for Xeriscaping
If your soil is primarily clay or sand, you may need to amend it so it will absorb and retain moisture, which is essential for xeriscaping. Although clay soil retains moisture well, it is slow to absorb it. Clay soil also tends to be heavily compacted, which makes it difficult for plants to survive during a drought. Sandy soil is exactly the opposite. It drains well, but does not retain moisture, which gives the roots little time to absorb the water. Either type of soil can be amended by adding organic materials, such as compost or manure. Soils are amended by blending the material at least six inches deep either by hand or with a rototiller.
You might want to consider having your soil tested for organic and nutrient content before adding any organic materials. This will ensure that you know what organic materials to add and help you choose the right plants for your soil. Testing kits can usually be found at your local nursery or home improvement store. If you do not want to hassle with amending your soil, you could consult with a horticulture expert and choose plants that will tolerate the type of soil in your yard.
The type of plants that you choose for your xeriscaping project will depend upon where you live. Native plants are usually chosen because they are naturally capable of tolerating the climate, but those are not your only options. Plants from other areas of the world that are also drought-tolerant or live in similar climates can also be used. It is important to note that plants will only be drought-tolerant once they have become established. This means more watering than usual should be done the first year or two after planting to help establish deep roots. You should also take care not to crowd plants, which would require them to compete for water. Annuals should be planted at least twelve inches apart, and perennials should be planted about 18 to 24 inches apart.
Once you have everything planted, it's time to add mulch. Mulch is an essential part of a xeriscape because it minimizes evaporation, reduces weed growth, and helps control erosion.
Organic mulch is wood-based. It helps improve the soil texture by decomposing over time, but this means that it will eventually need to be replaced. Organic mulch should be about three to four inches deep and should always be placed directly on top of the soil. Inorganic mulch is stone-based. Because it usually retains heat, it should not be used in sunny areas. Inorganic mulch can be placed on the soil or over a weed barrier fabric about two to four inches deep. Never apply mulch over black plastic because the plastic does not allow for moisture and air to penetrate and will kill useful organisms in the soil.
The last step is to maintain your yard. Luckily, maintaining a xeriscape is a lot easier than maintaining a regular yard. First, you spend much less time watering a xeriscape. In addition, xeriscapes usually have fewer problems with pests and disease and usually need less fertilizer. Using fewer pesticides and fertilizers is another benefit to both the environment and your pocketbook. This means that by transforming your yard into a xeriscape you get to save time, money, and the environment. Who could ask for more than that?