It is estimated that the average person uses 123 gallons (466 liters) of water per day and water resources are becoming more precious even in areas never before affected by shortages. Shortsighted water usage in the past has resulted in an all-time high in water dependency. If Americans are to enjoy the luxury of inexpensive water in the future, the practice of employing water efficiency practices must begin now.
Fortunately, specific steps can be taken to relieve pressures on water supplies around homes and in businesses without detriment to quality of life. Because the largest single use of municipal water may be in the landscape, it is an excellent place to begin water reduction demand. Professionals and homeowners can take an aggressive and positive attitude toward water conservation in landscape design and management. When basic horticultural principles are employed with an emphasis on water efficiency, landscapes use much less water because they’re drought tolerant, and home and business owners can save money in the long run.
Seven Xeriscape Steps to Save Money
The combination of water conservation techniques with landscaping is a concept known as Xeriscape or “dry landscape.” Xeriscape is a term that was coined in a Denver, Colorado program designed to promote water conservation in the landscape. While the idea began in the Western United States where landscapes can be truly dry, the same water-saving principles can apply to any landscape practice no matter the location. The seven basics Xeriscape principles include:
- Careful planning and design
- Appropriate lawn areas
- Thorough soil preparation
- Effective and efficient watering methods
- Use of mulch on trees, shrubs, and flowerbeds
- Proper landscape maintenance
- Appropriate use of plant materials
The greatest water efficiency is realized when all seven principles are used in combination. This translates directly into money savings for any homeowner or business, although some costs will be incurred on the front end (use a cash-back orreward credit card to save further, especially if you can pay off the expenses immediately). The combination of lower maintenance costs with greater survivability of landscape plants in times of water shortage, a Xeriscape is economically attractive.
Xeriscapes need not consist of dry-looking cactus and rock garden concoctions, as the gardener can employ existing principles of landscape design, construction, and maintenance to create water-efficient landscapes. Xeriscapes employ basic techniques to create state-of-the-art landscapes that save money and are beautiful.
1. Planning and Design
When you design a new landscape or renovate an existing one, it’s best to begin that plan on paper with a site analysis. This practice will save you time and money as you begin to learn how to best utilize your space. When you walk through the site with a pencil and piece of paper, you can sketch the following with notes:
- A layout of the existing walkways, buildings, decks, patios, and driveways.
- Note any existing trees, shrubs, and flower beds.
- Also note sun and wind exposure, topography, and drainage.
Once you’ve made these notes, consider the relationships among all the site features. Modifications that require grading, paving, or construction should be planned at this stage, but you might plan to keep the most desirable features within that landscape. Existing shade trees should remain wherever possible, because shady landscapes are cooler and need less water than sunny areas. If you can leave these trees or other features, your plans will save money. Other points to consider in your planning:
Decisions should be made about what size lawn area is needed, if any. Lawns usually take more water than any other feature within the landscape, so reduce the lawn size if possible. You can also save money on watering if you switch to a more drought-tolerant lawn species like Bermuda grass.
The site’s “microclimates” should be outlined on your plan as well. Microclimates are areas within a landscape design that have environmental conditions that differ from adjacent areas, such as the cool, shady north side of a building. One microclimate would be the hottest places in full sun on the south side of a building. Areas that receive more water, such as rainfall runoff from a roof or low spots that collect water are considered separate microclimates. Coastal residents must also consider the effects of salt spray as it greatly affects some plants.
These microclimates will influence your plant selection in all areas. A large shade tree on the south side of a house will lower temperatures and reduce water demands on an otherwise hot and sunny area. Cooler, shady areas on a building’s north side provide good environments for shade-loving species. Some plants thrive in cool morning sun with an eastern exposure, and other plants will work well in hot afternoon sun and western exposure.
To achieve the greatest water efficiency, your landscape plan can incorporate “hydrozones” or areas within a design that receive either low, moderate, or high amounts of water. All plants within a given zone maintain the same water requirements and can be watered as a group. For example, if you place high-water-use plants in a group, you can concentrate your water usage in just one area as needed.
High-water-use plants should not be placed near entryways or close to buildings, as you can create significant moisture problems and damage, especially to a building’s foundation. Low-water-use zone plants near building foundations will help to alleviate extensive mildew problems and moisture damage. Additionally, placement of dense shrubs near building foundations frequently blocks foundation vents that were installed to allow good air circulation beneath a structure’s floor. Finally, excessive moisture applied to plants near a building’s foundation also may promote pest problems. Research has shown [PDF] that termites, carpenter ants, and roaches thrive in moist locations.
Shade is also an important consideration in a water-efficient landscape. Surface temperatures can cool up to an average of thirty-six degrees in the five minutes following the arrival of the shadow line from overhead foliage. Lower temperatures mean less water loss by plants. However, plants placed directly under a shady tree face tree root competition, which may decrease water availability. “Dry shade” is a problem that must be considered when planting within a tree’s root zone. Shade is created by trees, but also by “hardscape” features such as walls, fences, arbors, and trellises.
2. Appropriate Lawn Areas
The concept of an appropriate lawn area is key to Xeriscape design. Lawn areas usually receive more water and require more maintenance than any other area in the landscape; therefore, you should select grasses carefully depending upon location, use and desired maintenance programs. Irrigated turf areas should be limited to the highest impact locations in the landscape.
Common Bermuda grass is among the best of all grass choices for Xeriscape design, especially in the south. This grass requires very low irrigation regimes and tolerates high sun. Several other warm-season greases become dormant and may wilt or become brown during severe water shortages if they aren’t irrigated, but they will often “green up” as soon as rain returns. Buffalo grass, Fine Leaf Fescue, Kentucky Bluegrass, among other grasses can be used in various climates depending upon traffic, weather, and temperature tolerance.
One technique that will help you to determine when a lawn needs irrigation, no matter which grass you’ve planted, is the “footprint” method. Walk across a lawn that isn’t covered with dew and examine the area behind you to see if you leave footprints. Footprints often appear when the grass plants contain low moisture. When you press grass blades with your foot, low water levels in the leaf tissues prevent the leaves from springing back. If your footprints remain for an extended time, the lawn should be thoroughly irrigated. This method will help to save money on irrigation when it isn’t needed.
Mowing the lawn at a proper height will help improve turf grass drought tolerance as well. Maintain cool-season turf such as tall fescue at three to three and one-half inches, and keep warm-season grasses such as Bermuda and centipede grass at one to one and one-half inches. Leave the lawn clippings on the lawn to mulch the turf and to reduce fertility requirements. This practice will also cut your water bills.
3. Soil Preparation
Soil is the medium for root growth and a reservoir for water and nutrients, so it’s basically the life support system for landscapes. Properly conditioned soil is vital for healthy landscapes and for saving money. Thing to look for in your soil include:
- If the soil is porous and will drain freely, yet it retains water and nutrients in a form that’s available to plants, then it’s a good soil that needs little additions.
- Soils that are hard and compact don’t allow water and air to penetrate to the root zone, and irrigation water is often wasted as runoff.
- Sandy soils dry out quickly and water and nutrients usually drain away before plants can use them.
If you’re unsure about the soil contained in your landscape, you can always take samples to a local county extension office so they can provide an analysis for you and recommendations for improvements.
Not all soil needs additions for improvements, but addition of organic matterprobably is the single most important method to improving soil structure. Organic matter increases water and nutrient capacity, aeration, and drainage. Plants and grasses that are planted in healthy soil are more vigorous and maintain greater disease and drought resistance.
Types of organic matter that you can use include sphagnum peat moss, pine bark, decomposed wood chips, and composted matter. As a rule of thumb, a minimum of four inches of organic matter should be tilled into the pant bed to a depth of one foot (12″). It’s important to enrich an entire flower or shrub bed, not just individual planting holes, so plants can form extensive and healthy root systems.
Trees and lawn areas don’t need extensive amendment; however, if you do amend your lawns, they will establish rapidly and grow stronger root systems. The type of tree also dictates soil amendment, as flowering trees like dogwoods prefer a richer soil than trees such as pines that will grow with little soil improvement. Finally, mounding the soil around a tree, shrub, or garden and sloping the bed will improve drainage and better survival of plants susceptible to drainage problems. This practice can also provide winter protection for many plants during a cold winter season.
On the other hand, mounding soil can often disrupt oxygen and water levels especially if you mound mature shrubs and trees. Conduct research on the plants that you plan to modify to learn more about how mounding and berming will affect those particular plants. A list of general tree and shrub care, for instance, can help to choose the trees and shrubs you need for your Xeriscape in advance. You can save money and time by learning more about your choices in advance rather than wait to be surprised by the bills wrought by unhealthy and inappropriate choices.
4. Watering Methods
A technique inherent to Xeriscape methods is efficient irrigation systems that provide appropriate amounts of water only at critical times. This irrigation system is designed to correlate directly to the hydrozones that you planned in step one. Turf areas, for instance, need to be irrigated by a separate system or by using timers to control the water amount the turf receives versus the requirements for shrubs, trees, and gardens.
Placement of the irrigation system also allows you to take drought conditions into consideration. Soil texture will influence your placement and the type of irrigation systems you choose. Drip and microsprinkler irrigation systems have many advantages, including that of saving money. They’re precise, they keep foliage dry, they’re simple to install, and they reduce erosion and water loss due to evaporation. They also reduce splash-transmitted soil-borne diseases associated with traditional sprinkler systems and they reduce mildew and decay on house foundations because they’re easier to control.
The amount of water that drip systems use is measured in gallons of water per hour, whereas the traditional sprinkler is measured in gallons of water per minute. That fact alone should help you decide which irrigation system to use if you’re budget minded. The drawback is that drip irrigation systems aren’t appropriate for lawn or ground cover plants.
You can also retrofit an existing traditional sprinkler system to serve as a drip and microsprinkler system, or you can use a soaker hose as an economical alternative to the drip system. If you want to spend a little more money as you design your Xeriscape, you can install a subsurface system that will eventually save money in the long run. Evidence suggests that the subsurface system can save up to 60 percent in water use, and because the water is placed directly at the root zone, wet/dry cycles are reduced. This system results in deeper root growth and healthier plants. Finally, all but the traditional irrigation system contains a low profile in the landscape, so vandalism can be eliminated.
After you’ve designed and installed your irrigation system, monitor the flow so that you don’t develop puddles or runoff. If you notice excess water, change the timing of the watering or split it so that the soil has time to absorb the water. A well designed watering system can save tons of money, but one error can wipe out those savings. But, the time and money you spend on proper irrigation will conserve needed water, reduce plant replacements, and will lower maintenance costs.
As much as 75 percent of the rainfall landing on bare ground is lost to evaporation and runoff. You can help prevent this loss by using proper mulch on your shrubs, trees, and flowerbeds. Mulch helps to insure plant survival and it’s an important component in Xeriscapes.
Two basic types of mulches are organic and inorganic. Examples of organic mulches include pine straw, pine bark mini-nuggets, wood chip mulch, composted leaves and grass clippings. Inorganic mulches include pebbles, gravel, black plastic and other landscape fabrics. While you can choose among many materials for mulches, price, availability, and aesthetic appeal will dictate your choice.
The best mulches are usually fine textured and non-matting organic materials, as these mulches allow runoff to percolate down through the soil. Any organic mulch should decompose slowly, be free of weeds, and should not be washed away easily by rainfall. Mulches that decompose quickly (such as grass clippings) are less desirable, but will help if you run out of mulch and need something to stand in for a substitute. Despite organic materials’ ability to decompose quickly, the benefits include an increased capacity to hold water in the soil, and the ability to reduce the amount of water lost by runoff and to moderate extreme soil temperature fluctuations.
Woody landscape plants need an application of three to five inches of any good mulch. This mulch should be applied under the plant and at least out to the drip line, because root systems can extend two to three times the spread of the plant. But mulch should be pulled away from the trunk of the plant to keep the bark dry. Since mulch increases the soil’s ability to hold water, the mulch should be six inches below any untreated wood siding along a building and at least eight inches below untreated wood structural members such as sills, joints, and plates.
One of the most important features to mulch is that it helps to regulate soil temperature. Summer heat is dissipated by mulch and the soil also is insulated from winter cold. Plants use less water when they’re not stressed by temperature modifications.
Weeds also compete with plants for water, and mulching can smother existing weeds and prevent new weed growth. Plus, when you reduce weeds by mulching, you reduce the need for fertilizer or weed killing applications. If you use landscape fabrics under organic mulch, this practice can reduce weeds even further.
Some considerations can help you make decisions about which type of mulch to use for your Xeriscape. Black plastic, for instance, can restrict water flow to plant roots and cause a heat buildup. Gravel can reflect heat to a plant’s canopy and increase that plant’s need for water. On the other hand, the consistent use of organic mulch can add humus to the soil, and humus increases a soil’s nutrient-holding capacity. Finally, mulches can provide a pleasing aesthetic to a garden, whether fully planted or not. Mulches can be used to create clean lines between planting beds and lawn areas or added to beds that are empty to create a pleasing contrast to surrounding growth.
Xeriscape principles can reduce maintenance as much as 50 percent through reduced water loss and soil erosion. Xeriscape designs also reduce mowing by limiting lawn areas, fertilization through proper soil preparation, and weeds through proper mulching. You can also reduce water use through proper irrigation systems, and costly damage to buildings through proper placement of those systems.
When you consider the contours of your property in your site planning and design, you also created hydrozones and microclimates that reduced the amount of water needed overall. You save money, time, and water when you planned your landscape to “fit” within these zones. When plants aren’t over watered, you can eliminate time spent pruning trees and shrubs. When you allow soils to dry between watering, you also encourage root systems to grow deeper. This Xeriscape technique helps plants to withstand periods of drought, as root systems are deep within the soil and closer to available moisture. Mulching will help to keep that moisture available even during periods of extreme drought.
7. Appropriate Plants
While you might think that cactus and gravel landscapes are the hallmark of Xeriscapes, lush green landscapes and seasonal colors are also components to Xeriscaping. With all Xeriscapes, careful planning and plant selection are important to insure your investment and the longevity of your landscape plants.
Basically any plant is a candidate for Xeriscapes. The key to success is how the plant is used. Your greatest successes will be achieved when plants are placed in environments most similar to the plant’s native habitat. With that said, many plants are adaptable and can perform equally well in different situations. You can determine a plant’s adaptability with research into that plant’s cultural requirements.
Coastal residents face the most challenges, because they must consider the influence of ocean breezes laden with salt. Salt spray and wind cause the foliage of many plant species to dry out, which results in severe damage or death. Additionally, beach soils are sandy and can retain little water and nutrients, while soils slightly inland may be heavy and poorly drained. Another problem for coastal residents is the poor quality of available irrigation water. Salts can penetrate underground aquifers, and these salts can injure landscape plants in a manner similar to the harm caused by ocean spray.
If you choose plants native to your area and group them in hydrozones to regulate irrigation, you should have a low maintenance and budget-friendly landscape. You must also consider the microclimate, soil structure, and light or soil temperature when you choose your plants. Ultimately, soil conditions will help with your choices. If you combine proper plant selection with other basic Xeriscape principles such as soil improvements, mulching, and proper maintenance, you’ll maximize your water savings.
Finally, remember that plants that are naturally drought resistant may grow stronger and faster when they receive extra water. Just because a plant is drought tolerant doesn’t mean it has to be used in a dry spot in your landscape. But drainage is important, and careful attention should be given to placement of species that require good drainage. Plus, it’s important to note that many drought-tolerant plants become tolerant only after they become established in the landscape.
The following list contains only a small fraction of the many Xeriscape plant lists you can find online. Plus, you can check out books at local libraries, visit a local county extension office or a university’s Master Gardener program, or a local botanical garden to learn more about native plants you can grow in your landscape. As you can see from the list below, you might include the area where you live when you search for Xeriscape or drought resistant plants online:
- Xeriscape Plants and Trees for the Southwest.
- Xeriscape Plant Selections and Ideas for North Dakota.
- Xeriscape Plant list from the University of Colorado
- Waterwise Florida Landscapes‘ plant list
Finally, check to see if you can receive a rebate for your Xeriscape plans and developments. For example, Aurora, Colorado’s water company offers its Aurora Water account customers a rebate for Xeriscapes up to 6,000 square feet, andAlbuquerque’s water authority offers rebates as well. Mesa, Arizona offers a Grass-to-Xeriscape rebate program, and the San Antonio program has taught residents how to measure water lost to evaporation from the soil and transpiration (breathing) from the leaf. The latter program has reduced lawn watering by 25 to 30 percent, potentially saving 29,000 gallons a year per household. If you can estimate how much money you can save if you conserve 29,000 gallons of water per year, then maybe you’ll understand Xeriscape’s value. Jump online, do a little research, and contact you local water board and other professionals who will be happy to help for little to no cost. Then you’ll be on your way to a drought resistant, beautiful, and money-saving landscape project.