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WATERING AND IRRIGATION
Landscapes can demand as much as 50% of the water a home uses. Wise water use helps to ensure water conservation, avert emergency water conditions, and allows homeowners to continue to water lawns and plants as needed.
Practice water conservation through creative landscaping:
- Arrange plants in groups according to their cultural and water needs. Plants frequently die when a habitat is too different from their natural habitat.
- Plant vegetation in zones according to similar watering needs:
A large lawn requires frequent mowing which takes up time or incurs the cost of lawn care service. Trees, shrubs, ground cover, and other native vegetation absorb many times more rainfall and require less maintenance than a mowed lawn.
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1) a very low water zone: native and drought-tolerant plants thrive here with no irrigation. Watering is needed for a limited time to establish new plantings.
2) a low water zone: plants here may occasionally require irrigation. Watering is needed only during extended drought. Plants in this zone can survive for a long time without rainfall. A mulched/planted border around a house is an example of a low water zone.
3) a moderate water zone: this zone is functional, limited in size, and easily maintained because it is separate from other plants. Lawn is one of the main parts of this zone.
4) a frequent irrigation zone: group plants that need frequent watering such as vegetable gardens, flower beds, and fruit trees in smaller areas.
5) special conditions: Areas with sandy soils, terrain where water drains off rapidly, and areas of the yard that are too far to reach with irrigation devices should incorporate drought-tolerant plants. Conversely, in areas with poor drainage or low wet areas, plant trees, shrubs, and ground cover that thrive in wet soils.
- Irrigation should be done in late evening, at night, or very early in the morning when winds and temperatures are low. Irrigation throughout the day is lost to evaporation. Winds are more likely to blow the water so that it is poorly distributed and does not soak into the ground.
- Never water during days or weeks of heavy rain. Turn automatic systems off.
- Direct water sprinklers away from paved areas. Don't water streets, sidewalks, and drainage ditches.
- Use efficient irrigation devices according to water zones and in areas which need more water. Sprinklers and pop-up spray heads which cover larger areas area best for lawns. Soaker hoses can be used in narrow areas such as borders and areas of ground cover. Low volume drips are suitable for areas where annuals are planted. Microjets and bubblers can be used to water individual trees and shrubs.
Don't water on a fixed schedule. Heavier spring and summer rains revive and turn lawns green overnight, so watering your lawn may not be necessary, especially if you leave your grass a little longer; 3 inches is about the best height for the least watering.
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Water is kept at the base of the plant so the root zone is irrigated. Bubblers are also useful in smaller areas around patios and pools. Check to make sure that the proper nozzle is being used, sprinkler heads are clear to ensure even distribution, hoses aren't clogged or leaking, devices are putting out the proper amount of water and covering each zone as required.
- Explore using super-absorbent water polymers for landscaping and gardening needs. Polymers form a transparent gel, capture gravitational water from rain or irrigation, and absorb many times their own weight in water which is released to plants as the soil dries out. Polymers promote healthy root systems and soil aeration, and they reduce transplant shock, leaching of nutrients, hard caking of the soil, evaporative water loss, and the rate of consumption.
- Avoid overwatering the lawn. Overwatering can lead to dollar weed and nut grass invasion. Soak the grass and soil in the root zone, not jut the top of the blades. Frequent light sprinklings can cause shallow rooting and open the yard to disease pathogens. Watch for signs of wilting and water the yard when the edges of grass are curling, the grass fades to a dull blue-grey, or when footprints leave an imprint on the lawn.
- Water lawns by applying 3/4 to 1 inch of water per irrigation. This will moisten the soil to a depth of 4 to 6 inches. To determine how long it takes your sprinkler to deliver one inch of water, place several cans at special intervals in the spray pattern and run the system until the water level in the cans averages one inch.
To water efficiently and for a more exact calibration, follow these steps:
1) For hose-end sprinklers, set 5 to 10 cans (3 to 6 inches in diameter) out at equally spaced intervals in a line from the sprinkler to the far edge of the water pattern. For in-the-ground systems, place the cans at random within one zone and repeat for each zone.
2) Turn on the water for 15 minutes.
3) Measure the depth of water in each container to the nearest eight-of-an-inch.
4) Calculate the average depth of water by adding up the sum of all the depths and dividing by the total number of cans.
5) Multiply the average depth of water by 4 to determine the irrigation rate in inches per hour. This is the amount of water soaking into the soil in one-hour. Use the table as a reference for how long your sprinklers should run. If your system operates at a rate of 1 inch per hour and you want to apply 3/4 of an inch of water, you would have to turn it on for about 45 minutes.
Amount of Water
to be applied |
½" |
1" |
1 ½" |
2"
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Time in minutes to run each zone |
| 1/4" |
30 |
15 |
10 |
8 |
| 1/2" |
60 |
30 |
20 |
15 |
| 3/4" |
90 |
45 |
30 |
30 |
| 1" |
120 |
60 |
40 |
20
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- Observe water use restrictions which are administered through local and county government agencies.
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