Friday, Sept. 6, 2019 | 2 a.m.
Powered by Southern Nevada Water Authority
If you didn’t change your sprinkler clock at the start of the month, it’s time to do so. September 1 marks the beginning of fall watering restrictions—decreasing our designated watering days to three days a week. “As the season starts to cool, watering restrictions change. Everyone needs to set their sprinkler and irrigation controllers to align with their fall watering schedule,” said Toby Bickmore, conservation specialist with Southern Nevada Water Authority. In addition to changing your clock, using smart irrigation strategies can help save water and money.
Cycle and soak method
Cycle and soak is an irrigation method that allows water to penetrate more deeply into the ground and is particularly effective for the hard soil found in the desert. “Plants need water to get within a certain depth, but hard soil can make that difficult. Grass usually needs 10-12 minutes per watering, but oftentimes the ground can’t absorb that much water at once, so we recommend using the cycle and soak method,” Bickmore said.
This method helps prevent water waste, reduces runoff and also makes for healthier plants by encouraging them to root more deeply in the ground. To institute the cycle and soak method ...
- Water 3 times a day, for 4 minutes each cycle
- Wait 1 hour between cycles
Though the recommended time to run each cycle is four minutes, three times a day, you can experiment with the timing to ensure your lawn is getting enough water before runoff occurs. Start the sprinklers and observe how long it takes before water spills into the gutter. If this happens at the three-minute mark instead of four, set your sprinklers to cycle for three minutes instead.
Types of irrigation
While sprinkler systems are best for grass, drip irrigation systems are ideal for desert plants because they deliver water directly to the ground. Drip systems should run longer than sprinkler systems because they work more slowly and efficiently, though the run time will depend on the specific type of drip emitter.
“The trick with drip irrigation is choosing the right head because there’s a wide variation of flow rates between drip emitters. Low-flow drip emitters dribble out slowly, whereas high-flow emitters come out in more of a stream, so you’ll need to adjust run times accordingly,” Bickmore said. If you look at the packaging, it’ll help guide you on how long it needs to run. With a slow drip system, you may need to run it for longer than with a streaming head.”
The number of drip emitters per plant also matters. Shrubs, bushes and groundcover generally need two to three low-flow drip emitters per plant. Trees, however, usually require more emitters, depending on the size and type of the tree. As a rule of thumb, drip emitters should be spaced evenly, beginning a few feet from the tree trunk to the edge of the canopy to efficiently apply water across the root zone. Add additional emitters as needed if trees and plants appear stressed and need more water.
Choosing sprinkler heads
Some sprinkler heads are more efficient than others. Bickmore recommends using multistream rotor sprinkler heads instead of typical spray sprinkler heads. “Brown spots are typically the result of bad irrigation—the issue is rarely about needing more water. The rotating heads are preferred because they can usually reach the spots spray sprinklers can’t,” Bickmore said. If you’re thinking about switching to multistream rotor sprinklers, be sure to change all the sprinkler heads for consistency. You should not mix-and-match rotor heads with spray sprinkler heads.
The grass you have matters
Consider warm-season grasses such as Bermuda, which require about one-third less water than other variations.
Test your systems
Check your sprinkler and drip irrigation systems regularly for broken components or leaks (especially after mowing or maintenance). Regardless of the season, monitor your landscape. If everything looks healthy, scale back your watering times slowly—a few minutes here and there—and see how it goes. Continue to evaluate and make changes throughout the year.
When to water
From May to October, water between midnight and sunrise to prevent water lost to evaporation. From November to April, water during the day to prevent freezing.