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Xeriscape* Design:
Principles of Sound Horticultural Practices

by Martha Latta, ASLA

What is xeriscape? The official definition is “water conservation through creative landscaping.” As a Landscape Architect, the “creative landscaping” phrase draws my attention and makes me wonder how creative landscaping conserves water. Let’s have a closer look at this definition.

A landscape becomes a xeriscape by incorporating seven principles of sound horticultural practices: good design, soil improvement, use of mulch, limited lawn areas, use of lower water demand plants, efficient irrigation and good maintenance. Creativity is what combines all these principles into an aesthetic and appropriate landscape for the locale.

The Landscape Architect has a slight edge on the other “green industry” professionals in promoting xeriscape, simply because turning the landscape into xeriscape starts with a good design.

Water, Energy and Labor

A well-designed xeriscape is not only pleasing to the eye, but will also require less watering as well as less money and time to maintain.

These are selling points to your clients. Keep in mind that xeriscape is designed for your clients’ use and to conserve natural resources--water, energy and labor.

During the site analysis phase of xeriscape design, pay particular attention to drainage, water availability, and micro-climate. Look for opportunities to be creative in using water already on the site. As you begin designing a preliminary plan, review the seven xeriscape principles for incorporation into your design.

Good drainage is essential to most xeriscapes. A soil test should be a standard part of your site analysis. The ideal soil mix should contain enough organic matter to hold moisture for plant use, yet porous enough to drain excess water.

Water Harvesting

Water harvesting is one concept of making the most of the water that falls on your site. Using berms or natural site elevations, you can channel runoff into low areas to create new, more moist micro-climates and increase percolation. These wetter areas are ideal for water-loving plants. To avoid frequent watering of quick draining berms, use drought-tolerant plants with spreading root systems that will stabilize the soil.

Mulch specifications for all planting beds should be a standard part of your construction documents. Specify an organic material that is readily available in your area and preferably low in cost. Some mulch materials that are industry by-products may be free for the asking. These may include pole peelings, chipper material or sawdust. A low-cost or free material encourages its use by your clients and avoids having it cut from the budget as an “unnecessary” expense. Mulch depth depends on the material being used. A good rule of thumb for mulch application is “the coarser the material, the greater the depth.”

Turf areas are the most resource demanding elements of the landscape on a per-square-foot basis. Remind your clients that large turf areas mean more water, more money and more maintenance time. Locate turf in areas where it serves a purpose, such as entertainment or play spaces. Turf should not be used soley as a visual element. Be creative in reducing turf areas by using ground covers, wildflowers, decks or other hardscapes.

Plant Selection

Proper plant selection is another xeriscape principle. You should select plants that are adaptable to the environmental conditions of your area. These native or adaptive plants will perform best in a landscape with minimal water and maintenance. A key to saving water in plantings is to match areas of similar use, microclimates and water-use zones. You will need to consider the soil, water and sun requirements of your plant selections. You should group plants according to their needs and place them where those needs will be met.

Low-water-use zones should be located at the outer limits of the site. You can use hardy native plants and wildflowers in these low activity areas such as side yards, corners of back yards and some portions of front yards. Once the plants are established, these areas can be left to thrive on natural rainfall.

Moderate water-use zones are areas of the landscape that are used occasionally, perhaps for a game of badmiton or volleyball. These areas may or may not include grass, and are usually located midway between the property line and the residence. You should plan for these areas to be watered on a regular basis; once a week or every ten days.

Lots of activity occurs in high-water-use zones. Locate these adjacent to the home. These will be the spaces used for entertaining, cookouts, young childrens’ play areas and any other frequent activity. These are also the best places to locate hanging baskets, potted plants and tender tropical plants. By being close to the house, it will be easy to give these plants the frequent watering they require. You will also be creating a cool, green oasis in the areas that are used the most.

Irrigation Technology

Consider irrigation in your planning process, even if it is to be temporary. All plantings will need to be watered regularly during the establishment period. It is only after the plants are well-rooted that they can be slowly weened and watering reduced, or even eliminated, as in the case of the wildflower or some hardy native plants. Be creative in designing "hybrid” irrigation systems that combine conventional pop-up sprays, micro-sprays and drip to efficiently water different plant types. Keep abreast of the latest irrigation technology for the greatest possibilities of conserving water.

Finally, be realistic with your client about maintenance. All landscapes require some degree of management to maintain the goals of the design. In an efficient Xeriscape, less time should be required for maintenance. Write a maintenance plan for your clients so that they feel it is a true reflection of how much time or money they are willing to spend keeping your design looking the way you intended.

Xeriscape is an opportunity for you as a designer to be steward of our natural resources and promote pride in regional landscapes. Xeriscape helps your clients take an active role in conservation. Not only in natural resources, but savings in utility bills, maintenance bills and costs!

Martha Latta is program manager for the city of Austin, Texas, xeriscape program, which she has been organizing and implementing since July, 1984. Latta is a Texas State registered Landscape Architect and irrigator. She serves as president of the National Xeriscape Council, Inc, and past chairperson of the Austin Section of the American Society of Landscape Architects. She is also a member of the Texas Turf Irrigation Association’s water conservation committee.

*Xeriscape is a registered trademark of the National Xeriscape Council.


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September 18, 2019, 3:57 pm PDT

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