Learn How to Water

Plants come in four water use categories - high, moderate, low, and very low water use - and the recommended watering times are different for each category. And, watering times vary by season. It's complicated, but we have two tools that make it simple.

Better Tool
Use the city of San Diego's Landscape Watering Calculator. It gives you recommended watering times for each month of the year based on your zip code, plant water use category, soil type, and sprinkler type. If one area of your yard is watered with spray nozzles and another area with drip, get separate watering schedules for those areas. Or, if you have high water use plants in one area and low water use plants in another, get separate watering schedules for those areas.

Best Tool
Weather-based irrigation controllers automatically adjust watering times each day based on the weather. They get the weather data from a sensor you install on your fence or home, or from the State of California's CIMIS weather stations. Note that we offer a rebate to make this technology available to homeowners and large properties.

Spray Heads
Spray nozzles are very common but have two issues. First, they apply water faster than most soil can absorb it. Second, wind can blow the small water drops off target. These two issues result in water running onto sidewalks and into the street. 

Rotors
Rotors shoot a single stream of water that moves slowly over a landscape, giving soil time to absorb the water. Rotors are an efficient sprinkler and are a good choice for large landscapes.

Rotary Nozzles
Rotary nozzles put out large, wind-resistant water drops in multiple, rotating streams of water. They water slowly and can be up to 30 percent more efficient than spray nozzles. They are the best choice for watering areas, like lawn and groundcover.

Drip
Drip irrigation is the most efficient way to water plants and trees. Water is applied one drop at a time, directly into the soil, within the plant's root zone. Not irrigating the area between plants saves a lot of water and reduces weeds. 

If your sprinklers apply water faster than your soil can absorb it, water will run off of your landscape, on to the sidewalk and into the street. To prevent runoff, use rotors, rotary nozzles and drip irrigation. Another way to prevent runoff is to reduce your watering times and water more often.

Use Multiple Start Times
Some irrigation controllers offer multiple start times on the same day within one program, while other controllers require you to use multiple programs.

On Start Time 1 or Program A
Schedule the same days and 3:00 minutes at 12:00am

On Start Time 2 or Program B
Schedule the same days and 3:00 minutes at 2:30am

On Start Time 3 or Program C
Schedule the same days and 4:00 minutes at 5:00am

Use the Cycle and Soak Option
Some irrigation controllers have a cycle and soak option, which will automatically divide a 10 minute watering cycle into smaller cycles.

The optimal water pressure for drip irrigation and sprinklers ranges from 20-40 psi. But a home’s water pressure can be as high as 70 psi. Regulating the pressure in your irrigation system can save a lot of water.

Example
Above is an excerpt from a spray head performance chart. The nozzle’s optimal water pressure is 30 psi, and at 40 psi the nozzle’s flow rate increases by 0.4 gallons per minute. That’s wasted water. It doesn’t sound like much, but it adds up quickly.

4 Gallons = wasted water in 10 minutes from one sprinkler

240 Gallons = wasted water in 10 minutes from 60 sprinklers in a landscape

33,120 Gallons = wasted water from 60 sprinklers in one year

Measure Your Water Pressure
Buy a water pressure gauge at a hardware or irrigation supply store. Screw the gauge on to a hose bib outside your home and turn the water all the way on. If your pressure is higher than your sprinklers’ optimal pressure, you can save water by installing pressure regulation devices in your irrigation system.

Install Pressure Regulation 
Manufacturers make irrigation valves and sprinklers with built-in pressure regulators, or you can attach a pressure regulator. Learn more by watching videos on manufacturer websites and ask one of the experts at an irrigation supply store what they recommend.