Xeriscaping: Creative Landscaping
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Xeriscaping: Creative Landscaping Fact Sheet No. 7.228 Gardening Series|Basics by C. Wilson, J.R. Feucht and Susan Carter* Xeriscaping (zer-i-skaping) is a word exposures can raise temperatures near the Quick Facts originally coined by a special task force of house and result in wasteful water runoff and the Denver Water Department, Associated increased temperatures. • Proper planning is the first Landscape Contractors of Colorado and step in landscaping to reduce Colorado State University to describe water use. landscaping with water conservation as a Slope of Property major objective. The derivation of the word Slope or grade is another consideration. • Steep slopes with south and is from the Greek “xeros,” meaning dry, and Steep slopes, especially those on south and west exposures require more scape meaning the pattern of the landscape – west exposures, waste water through runoff frequent irrigating to maintain thus, xeriscaping. and rapid water evaporation. A drought- the same plant cover as east The need for landscaping to conserve resistant ground cover can slow water loss or north slopes. water received new impetus following the and shade the soil. See fact sheet 7.230, • Terracing slopes reduces drought of 1977 throughout the western Xeriscaping: Ground Cover Plants, for states and the recognition that nearly 50 suggested ground covers. Strategically placed runoff. percent of the water used by the average trees can shade a severe exposure, creating • Limit irrigated bluegrass turf household is for turfgrass and landscape cooler soil with less evaporation. Terracing to small or heavily used areas. plantings. slopes helps save water by slowing runoff and Unfortunately, many homeowners have permitting more water to soak in. • Soil amendment is a key to cut back on turfgrass areas by substituting water conservation. vast “seas of gravel and plastic” as their Reduce Irrigated Turf • Proper irrigation practices, answer to water conservation. This practice is not only self-defeating as far as water Avoid narrow strips of turf, hard to system design and audits can conservation is concerned, it also produces maintain corners, and isolated islands of lead to 30 to 80 percent water damaging effects to trees and shrubs. This is grass that need special attention. Not only savings. is maintenance more costly, but watering not xeriscaping. • Organic mulches can keep becomes difficult, often wasteful. If your yard is already landscaped, see 7.234, Xeriscaping: the soil moist and improve the Planning – The First Step Retrofit Your Yard, for information on ways soil overtime. Whether you want to redesign an old to evaluate and eliminate unneeded turf grass landscape, or start fresh with a new one, a areas. plan is essential. Site exposure is an important Reduce bluegrass turf to areas near the component of the plan, no matter how simple house or that of high use. If appropriate, try the plan. As a rule, south and west exposures using more drought-resistant grasses or even result in the greatest water losses, especially meadow mixes containing wildflowers. Refer areas near buildings or paved surfaces. You to 7.232, Xeriscaping: Turf and Ornamental can save water in these locations simply by Grasses, for suggested alternatives to changing to plants adapted to reduced water bluegrass. use. However, don’t be too quick to rip out the sod and substitute plastic and gravel. Soil Preparation Extensive use of rock on south and west Proper soil preparation is the key to * J.R. Feucht, Colorado State University Extension landscape plants specialist and professor (retired). successful water conservation. If the soil is © Colorado State University Prepared in cooperation with the Technical very sandy, water and valuable nutrients will Extension. 12/96. Revised 3/19. Advisory Committee for Xeriscape Front Range, an be lost due to leaching below the root zone. If extension.colostate.edu affiliate of the National Xeriscape Council, Inc. Reviewed your soil is heavy clay, common in this area, by C. Wilson, Extension Horticulture Agent, Denver you will lose water through runoff. County. 10/07 Amended by Susan Carter, Extension Horticulture Agent, Tri River Area. 3/19. A good soil is one that supports healthy Note #241: Soil Amendment. This Avoid frequent, shallow sprinklings that plant life, conserves moisture and has a encourages deep roots that tap the water lead to shallow root development. Compact balance of soil clusters (aggregates) and stored in the soil and reduces the need for soils result in quick puddling and water pore spaces. The “ideal” soil has as much as wasteful, frequent water applications. runoff. They need aeration with machines 50 percent by volume pore space, with the that pull soil plugs. Fine compost applied at soil itself consisting of a good balance of ¼” depth after aerating can improve the soil. sand, silt and clay creating a loam soil. Proper Irrigation Saves Water trees and shrubs separate from the A major problem with heavy soils is that Water lawn ensuring that the soil is watered to a clay tends to dominate the soil complex. Proper irrigation practices can lead to a depth of 12-18”. Clay is composed of microscopic crystals 30 to 80 percent water savings around the arranged in flat plates. When a soil has home grounds. Check existing sprinkler Mulching the Landscape a high number of these crystals, they act systems for overall coverage. See Lawn much like a glue, cementing the particles Irrigation Self Audit (LISA) website. If Properly selected and applied mulches of sand and silt together and resulting in a areas are not properly covered or water is in flower and shrub beds reduce water use compact, almost airless soil. falling on hardscapes, adjust the system. by decreasing soil temperatures and the Such soils often repel surface water This may mean replacing heads, adding amount of soil exposed to wind. Mulches (hydrophobic soil), resulting in runoff. more heads, or adjusting to do a more also discourage weeds and can improve soil When water does get into these soils, it efficient job. conditions. is held so tightly by the clay that it is not With the system on, observe places The two basic types of mulches are available to the plants. Plants in a clay soil, that are receiving water where it is not organic and inorganic. Organic mulches even though it is moist, often wilt from lack needed. Overlaps onto paved areas or into include straw, partially decomposed of moisture. Plant roots also need air to shrub borders may result in much water compost, wood chips, bark, fiber mats, thrive. In clay soils, air spaces are small and waste. Overwatering trees and shrubs may and even ground corncobs or newspapers. fill with water, so plant roots often suffer lead to other plant health issues and other Inorganic mulch is mainly gravel. Plastic from oxygen starvation. problems. film or polyethylene film and woven fabric is In very sandy soils, the opposite is Irrigate turf areas differently than shrub not recommended as oxygen and water does true. Sandy soils have very large particles borders and flower beds. North and east not penetrate it, hurting trees and shrubs creating large pore spaces. Because the exposures need less frequent watering than root systems. A combination of both organic particles are large, there is little surface area south and west exposures. Apply water to and inorganic can be used. Plastic mulches to hold the water, so they tend to lose water slopes more slowly than to flat surfaces. are options for annual vegetables. rapidly. Ideally, these are different irrigation zones If soil improvement is a priority, use Creating a good soil takes more than (Hydrozones). Examine these closely and organic mulches. Wood chips and compost a year. Add organic matter annually to correct inefficiencies in irrigation system are most appropriate as these materials break garden areas. In areas to be sodded or design. down becoming an organic amendment seeded, add organic amendments as a If you do not have a sprinkler system to the soil. Earthworms and other soil onetime procedure. Since this is your and are just beginning to install a organisms help incorporate the organic one chance to add a good amendment landscape, you can avoid the pitfalls of component into the soil. Organic mulch thoroughly 6-8” deep. See: CMG Garden poorly designed and installed systems. is preferred because most soils in this area Have a professional irrigation company are low in organic content and need organic do the job correctly. Make sure the amendments to improve aeration and water Steps to Xeriscaping system is designed to fit the landscape, holding capacity. Inorganic mulches, such as rock or gravel, •Plan your landscape including your the water needs of the plants, and is zoned to reduce unnecessary applications of without fabric or plastic, allow for water and property’s exposure and slope and water. Coordinate the landscape design air exchange. See 7.214, Mulches for Home your family uses. to select plants that have similar cultural Grounds. •Reduce irrigated turf where requirements and match the irrigation appropriate and replace it with low- system to those needs, resulting in a Selecting Plants water alternatives. sensible water-saving scheme. Consider a drip system for outlying Carefully select plants to be compatible •Prepare the soil. This is your best shrub borders and raised planters, around with soil, exposure and irrigation systems. opportunity. trees and shrubs, and in narrow strips For recommended plants, see: where conventional above ground systems 7.229, Xeriscaping: Trees and Shrubs. •Select appropriate plants. would result in water waste. 7.230, Xeriscaping: Groundcover Plants. •Irrigate properly. If you use hoses instead of an 7.231, Xeriscaping: Garden Flowers. underground system, you can observe 7.234, Xeriscaping: Retrofit Your Yard. •Use mulch to save water, inhibit water patterns.