Transcript of "Developing A Water-Efficient Landscape - University of Nevada, Reno"
COOPERATIVE EXTENSION Bringing the University to You Fact Sheet 91-54 Developing a Water-Efficient Landscape Dr. David M. Cox, Extension Educator, East Clark County Throughout the West, people are changing doesnt grow – decks, patio, sidewalks, fences,traditional ideas of planting and maintaining benches, gazebos, etc.).home landscapes. Drought, agricultural irriga- To establish a water-efficient landscape,tion, urban development, and growing popula- consider the following ten guidelines.tion are placing increased demands on available • planning and designwater. As the demand for and the cost of water • practical turf areasincreases, water-efficient landscaping is a trend • efficient irrigationgaining in popularity. • soil amendments A number of terms describe water- • mulchesconserving landscaping. Among them are • appropriate plant selection"xeriscaping," "low water use," "drought- • plant at proper timestolerant," waterwise," and "desert" landscaping. • windscreensXeriscaping, a widely promoted term the past • maintenanceseveral years, is a word of Greek origin with • flexibilityxeros meaning dry, combined with landscaping.Drought-tolerant indicates the ability of a plant Planning and Designto survive on limited water, although these Start by drawing a plot plan of your propertyplants usually look better as water is increased. to scale on graph paper (1/8" or 1/10 " = 1, forWith improper watering, a drought-resistant example). Include all the buildings, doors andplant may become a water guzzler in the land- windows, driveways, property lines, porches,scape. This publication will use the term "water- steps, sidewalks, buried services (water, tele-efficient" to describe the water-conserving land- phone, etc.) and any other features including thescape. present landscaping. Unfortunately, many people associate water- Make your plot plan complete and accurate,conserving landscapes with sand, gravel, cactus, and draw plants to at least 3/4 of their matureskimpy plantings, and a hot sun-baked look (the size. This will prove invaluable in helping you"desert" image). Nothing is further from the visualize the features of your yard and considertruth. The potential beauty of these landscapes plant placement. Common mistakes includewhen well designed is limited only by the planting trees and shrubs too close to houseimagination. The idea is to maintain the beauty foundations, septic systems, under eaves orwithout being thirsty. where they encroach into walkways and drives. A water-efficient garden is a "balanced Include locating plants where they receive pro-landscape," one that uses water efficiently and tection from sun and wind (next to buildings,balances the lawn area, shrubs, and flowers with decks, or porches), and situating sun and wind-the hardscape (everything in the landscape that screens to protect your home. (Continued on page 2)
(Continued from page 1) The Elemental Hyrdozone includes natural In planning your landscape, group plants plantings that are capable of surviving on thewith similar water needs together in the layout, available natural precipitation. No supplementaland locate turf strategically for function, benefit, irrigation takes place in this zone and plantingsand water efficiency. Zoned irrigation seldom, if ever, come into human contact or ac-(hydrozoning), the most efficient way to irri- tivity. Utility areas and mulched, native plant-gate, delivers water to individual plants or ings are examples typical of this hydrozone.matches the amount of water applied to plantswith similar moisture requirements. By reducing Practical Turf Areasoverwatering and runoff, fewer plants will die or A water-efficient landscape promotes adevelop diseases that result from overwatering. practical turf area that is based on function. It The concepts of hydrozoning are based on includes no more turf area than what is requiredthe interaction of people with areas of the land- for the family recreational area or to satisfy thescape. Areas of high people activity result in personal needs and desires of family members.more contact and interaction with plants, which As you plan, remember that a lawn is an in-result in more requirements for supplemental tegral component of many landscapes. At theirrigation to support these plantings. Areas of same time, the lawn represents the single great-less people activity require fewer plantings and est area for misuse of irrigation in the land-less supplemental irrigation. Generally, there are scape. In the Desert Southwest, turf must be irri-four potential hydrozones found in a landscape. gated or it will become stressed and eventually The Principal Hydrozone is the area of lost. Drought-tolerant turfgrass species such asgreatest human activity and interaction with the Bermuda are available that will survive extremelandscape. This high-traffic area is both func- drought conditions. These varieties may turntionally and visually important as the place brown under such conditions, but will green upwhere people walk, sit, play, relax, and contact again when water is applied.the plant environment. Sometimes referred to as Lawns require mowing, fertilization, weedan "oasis" in landscape design, this area of the control and other intensive maintenance activi-landscape results in the greatest water use. ties to keep an attractive appearance. Use the The Secondary Hydrozone is visually im- following guidelines to reduce turfgrass irriga-portant to the landscape, but represents an area tion.of less human traffic and interaction. These ar- • Zone your landscape and locate turf areaseas are more passive in function and serve to de- based on water use.lineate space and design. Accent areas such as • Plant adapted, low-water demand turf spe-flower borders, shrub beds, bulb gardens, or cies and varieties.specimen plants are all examples of the types of • Use turf in areas that provide functionmedium-water-use plantings found in a secon- (recreational, aesthetic, foot traffic, dustdary hyrdozone. and noise abatement, glare reduction, tem- The Minimal Hydrozone contains plants that perature mitigation).require minimal water to survive the existing • Irrigate turf based on true water require-climatic conditions. These areas receive infre- ments.quent contact with people and are less visually • Reduce fertilizer and make applicationsimportant in the landscape. Buffer zones, se- only when grass turns off-color and irriga-cluded or screened views, parkways, and em- tion is available.bankments are all examples of this zone. The The turf needs of every family are different.typical vegetation in this hydrozone includes Some experts recommend that a maximum oflow-water-use and drought-tolerant trees, 25% of the landscape is enough turf. Others sayshrubs, and ground cover. that 600 to 800 square feet is adequate for most family activities. (Continued on page 3)
Efficient Irrigation Soil Amendments Properly designed, installed, maintained, Desert soils are poor and require the addi-and operated sprinkler and drip irrigation sys- tion of organic matter to improve them. Routinetems may apply water very efficiently to the cultivation with the incorporation of organiclandscape plants. Plant selection will determine matter (manure, peat moss, rotted sawdust, com-which system to use. Often a combination of post, etc.) will increase the ability of the soil todrip for trees and shrubs, and sprinkler for turf conserve water and avoid compaction.and ground covers works best. With drip sys-tems, plan and install sufficient emitters to water Mulchesindividual plants thoroughly and deeply. The The use of organic and inorganic mulches insystem must have sufficient capacity to allow the landscape will conserve soil moisture by re-the addition of emitters as the plants grow. Lar- ducing evaporation. Also, as these mulches de-ger plants will require more emitters with time. compose, they mix with the existing soil to im- Whatever system you use, keep it well prove it. Mulches also prevent weed growth andmaintained and in good working order. Check control erosion in problem areas.the system frequently to se it is operating effi- The use of mulches adds interest and colorciently, repair leaks, clear plugged sprinkler to the landscape. These materials also serve asheads and emitters, and correct uneven water an alternative for turf. Examples of organicapplications. Place emitters to water trees and mulches are bark, well-rotted sawdust, peatshrubs evenly about the plant. Maintain flexibil- moss, and compost. Inorganic mulches wouldity with the system, as emitters will require include colored stone, rocks, and gravel.moving as the plant grows. Both drip and sprinkler systems have the ca- Appropriate Plant Selectionpabilities of clock-controlled watering. This is a Selection of your permanent plants shouldbig advantage for watering while you are away follow careful thought and include the needs,from home. It is also a disadvantage when the use, and desires of the family. Final selectionsentire system relies on a control device, and gar- of turfgrass and woody plants should be adapteddeners need to recognize that malfunctions are a to the existing climate. For a list of water-possibility. The drip system requires long run efficient plants, request Fact Sheet 91-32, Lowtimes and is separate from the controller for the Water Use Plants of Southern Nevada.*sprinklers. However, more expensive clocksmay accommodate both. Plant at Proper Times Remember that clocks will need adjustment The best time of the year to plant is in theto match the seasons and the watering require- spring or early fall. Plant annuals and herba-ments. To prevent evaporation and wind drift, ceous perennials in the spring so they becomeset your system to water early in the morning (6 established before the arrival of harsh summera.m.). Select and install emitters that will apply conditions. Shrubs and trees have the best suc-sufficient water to deep-water your plants for cess when planted in the fall. Fall planting en-the time and days the system is operating. courages root development, and plants become Make sure you dont overwater. Runoff, well established before winter dormancy.visible by simple observation of your systemwhen operating, wastes water and leaches nutri- Windscreensents. Overwatering also results in a continual Some of the more tender landscape plant-saturation of the plant root zone and will kill or ings may need protection from the hot southerlydamage many plants. Periodically, heavier soils summer winds or the cold, northerly flows ofwill require leaching with additional watering to winter. Either of these drying winds will quicklyflush the salts. desiccate or dry out plants. Careful planning (Continued on page 4)
(Continued from page 3) Flexibility(determine the prevailing wind directions for Gardeners in desert climates have a chal-your property) and the use of hardscape lenging assignment. Harsh weather, poor or(buildings, fences) will shelter plantings from salty soils, mixed irrigation methods, drought,both wind and sun. Buffer zones created by har- and poor drainage are factors the successfuldier trees and shrubs will also protect plantings. landscaper must master. Paying attention to de-Evergreens are often planted to create year- tails, exercising patience, and remaining flexibleround protection for the less wind-tolerant as you develop and work with your landscapeplants. Examples of evergreens planted as wind- all help.breaks include Oleander, Blue Point and Spartan Of the guidelines offered for water-efficientJuniper, and Italian and Leyland Cypress. landscaping, water management provides the greatest opportunity for water conservation in Maintenance the landscape. Remember that plants do not Haphazard maintenance results in wasting waste water, people do. Also, irrigation systemsmany gallons of water per year and defeats the do not save or waste water, people do. To de-purpose of establishing a water-efficient land- velop water-efficient landscapes, it is first nec-scape. Water-efficient landscaping requires pay- essary to change attitudes and irrigation habits.ing attention to details: We can all do much to use water efficiently in • eliminate leaking faucets and valves the landscape. • sprinkler and drip systems distribute water evenly *For northern Nevada, request "Fact Sheet • sprinklers are upright and at grade 88-73, Hardy, Drought-Tolerant and Mod- • water plants when they need the moisture erately Salt-Tolerant Trees for Northern Ne- • apply the actual amount of water plants vada or "Fact Sheet 89-05, Hardy, Drought- need and apply it at a rate the soil can Tolerant and Moderately Salt-Tolerant readily absorb. Shrubs and Vines for Northern Nevada". Other maintenance activities include weed- References:ing, fertilizing, mowing, and pruning. Weeds Korr, Marge. (1992 July/August) Countdown togrow well in the irrigated landscape areas and Xeri. National Gardening, 24-27.take water from desirable plantings. Eliminate Smith, Ken. (1978). Western Home Landscap-or control weeds by hoeing, hand pulling, or us- ing. Tucson, Arizona: HP Books.ing a herbicide. After weeding, apply a mulch to Waterwise Gardening. (1989) Menlo Park, Cali-these problem areas to control future weed fornia: Lane Publishing Co.growth. Welsh, Douglas F., Ph.D. (1991) Practical turf Fertilizing and pruning are maintenance ac- areas: the controversial xeriscape guideline.tivities performed on an "as-needed" basis. Turf and the Landscape Architect.Spring is the best time to fertilize turf. Use ahigh-potassium fertilizer and follow the instruc- The University of Nevada, Reno is an Equal Employment Op-tions on the package for the amount to apply. portunity/Affirmative Action employer and does not discrimi-Excessive fertilization will cause unnecessary nate on the basis of race, color, religion, sex, age, creed, na-growth that will use more water. Taking a soil tional origin, veteran status, physical or mental disability, and sexual orientation in any program or activity it operates. Thetest every two to three years will identify soil University of Nevada employs only United States citizens anddeficiencies and determine fertilizer needs. aliens lawfully authorized to work in the United States.