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It is important to note that a newly installed landscape will require more water during an establishment period of one to two years. After this time, a Xeriscape landscape may require no irrigation unless it is a drought period. Unless there are large expanses of non-native turf and other thirsty plants, some quick-couplers (temporary hose connection) in conjunction with drip irrigation may be sufficient. However, many homeowners prefer the convenience an automatic irrigation system provides.
Features such as multi-cycling (or multiple start times) will help in watering areas which may need several short irrigation cycles to avoid runoff.
An inexpensive rain shut-off device, which will prevent unnecessary irrigation during rain.
A soil moisture sensor. Unlike the rain shut-off device, the soil moisture sensor actually measures soil moisture, and overrides programmed irrigation when the soil moisture level is adequate.
Non-mist type low trajectory nozzles and pressure-compensating devices for spray systems in turf areas. or micro-spray heads should be used for spray systems in turf areas.
A zoned approach whereby plants of similar water requirements are grouped together in the same zone capable of independent station programming (i.e. turf areas separate from shrub areas, sunny areas separate from shady areas).
Drip irrigation systems are ideal for watering plants in beds and gardens.
Drip irrigation uses a flexible hose system which can be easily modified, to apply water at the ground surface to individual plants. Emitters are punched into the supply line where they are needed. A variety of types and flow rates for emitters are available.
If water pressure at the source exceeds 30 psi, a pressure regulator may be necessary. Filters to remove sediment should be installed at the water source. Flush caps should be installed at the ends of the drip supply lines so that the entire system can occasionally be flushed of contaminants.
Drip lines should be secured to the soil surface and covered with organic mulch to improve appearance and protect them from sunlight.
A complete system audit should be conducted annually, and irrigation schedules adjusted quarterly at a minimum. (A training program for Irrigation Auditors is now offered by the Texas Agricultural Extension Service.)
Irrigation lines should be flushed and all stations, heads, nozzles, and/or emitters checked for proper functioning.
Post the current irrigation schedule inside the controller box. (Be sure to note that seasonal adjustments to the irrigation schedule will be necessary.)
Give the owner an orientation session on how to operate the system. Many irrigation systems which are efficiently designed are never used efficiently because the owner is unaware of the importance of his/her role in scheduling and maintenance after the system is installed.
Offer a maintenance and seasonal system adjustment visit as a part of your follow-up package.
Irrigate in the coolest part of the day (early mornings and evenings) to avoid evaporation loss and wind drift.
Nighttime watering can encourage disease.
Irrigation equipment should be tested to determine how long it takes to apply one inch of water.
Wet the soil to a depth of five or six inches, and allow it to dry out between waterings. (The homeowner can learn to recognize the signals of a thirsty landscape. Shrubs will begin to droop and grass will lie flat and leave footprints when walked on.)
As a general rule, during the growing season most grass needs about one inch of water per week. This will vary depending on soil type and depth, sun, plant conditions, and rainfall occurrence.
Watering can taper off gradually as fall arrives and gradually increase in spring.
Plants don't need as much water in winter, but will still benefit from monthly irrigation if there is no rainfall.
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Sustainable Building Sourcebook web version copyright Sustainable Sources 1994-1999.