It's best to run your sprinklers 2 to 3 times per week.
Water Wisely
Most lawns need to be watered no more than three days a week in the spring as well as in the summer and two days a week in the fall. This watering schedule is recommended under normal water supply conditions.
The ideal watering schedule is once or twice per week, for about 25 to 30 minutes each time. Taking care of a lawn doesn't have to be an overwhelming, all-consuming task.
In the late spring, rotor irrigation zones typically need to run 30-45 minutes per zone, and spray irrigation zones typically need to run 8-12 minutes. We recommend watering 2-3 days a week during late spring. In mid to late summer with extreme heat, your lawn will need more water.
For example, rotor sprinkler heads might require 20 to 30 minutes of straight watering time, while a traditional spray head zone will only need 5 to 10 minutes.
Running multiple zones at once is usually not possible due water-pressure and flow limitations at residential properties.
If you're not sure how much time it takes for your sprinklers to spray an inch of water, you're not alone. A fixed spray head nozzle might take ~30 minutes to apply 1 inch of water, whereas a rotary nozzle could take 3x as long to apply the same amount.
Warm-season grasses have extensive root systems that penetrate deep into the soil and require deep and infrequent watering. Water as few times a week as necessary to fulfill your weekly water requirements without causing excessive runoff. Usually 1 or 2 times a week is sufficient.
To keep your irrigation investment safe, monitor the weather and wait until temperatures consistently remain above freezing through the night. Typically, the best time to start up your sprinkler system is between the middle of April and the middle of May.
1-2-3-2-1 watering technique:
In April water 1 day/week. In May ramp up to 2 times/week. In the heat of the summer water 3 times/week. In September drop back to 2 times/week. In the fall drop back down to 1/week.
If your grass is actually dead, there's nothing you can do to bring it back other than plant new grass. Brown grass, however, can green up following proper care. Oftentimes, that just means water, nutrients, and cooler temperatures for northern lawns and warmer temperatures for southern lawns.
The average system uses approximately 15-16 gallons per minute, per station. Here is an easy formula to help you calculate the approximate amount of water you are using each month.
As for how long to leave the sprinklers on, it varies. However, the average time to water lawns so that they are properly hydrated is 60 minutes per week. So, turning on your sprinkler for 30 minutes twice per week is a good starting point for creating your own custom schedule.
Most homeowners should fertilize their cool-season turf in March, then May, then from September to October. However, UC IPM recommends that lawns in the Sierra area should be fertilized from May to June and August to September.
A typical lawn needs about an inch of water per week, equating to two 30-minute watering sessions.
Between irrigation and natural rainfall, your grass should receive between 1 and 1.5 inches of water each week during the summer. Water deeply every other day for the best results. Your turf should receive about 1/3 an inch of water every two days in order to maintain deeper roots, thus helping protect against drought.
Most turfgrass plants can stay in a dormant state for at least 3-4 weeks without the grass dying (longer if the dormancy is induced by cold). If drought goes beyond the 4 week mark, apply enough water to rehydrate the grass slightly and wet the soil down to a 5-inch (12.5 cm) depth.
Now I know most of my zones need 15 minutes per cycle, one needs 10 minutes, and one needs 20 minutes. It really does vary, depending on how many sprinkler heads are on a valve, and how much pipe the water has to run through before it gets to that valve. And the same thing applies to a hose and sprinkler set up!
Nothing should be in that area between the bottom of the sprinkler heads and the imaginary horizontal plane parallel to the ceiling that is 18 inches below. This is done to allow an even and unobstructed spray pattern from the sprinklers when triggered to extinguish the fire.
According to lawn care experts, the best time to water grass is in the early morning, ideally before 10am. During this time, the temperature outside is still relatively cool, and the wind and sun are less intense.
Each system delivers water at a different rate, but this is typically about 30 to 45 minutes per zone. When using a sprinkler system, you want to be as efficient as possible and use water judiciously. You want to give your grass enough water to meet its needs without overeating and being wasteful.
1 of NFPA 13, which states that the distance from the sprinkler to the wall can be no more than one-half the allowable distance between sprinklers. The max distance between standard spray sprinklers in light hazard settings is 15 ft. (4.6 m) (with exceptions for light-hazard, combustible concealed spaces).
If your heads consume 3 GPM, you could run three heads per zone. Each zone of a sprinkler system will run all of its heads simultaneously. If you have too many in a zone and not enough pressure, each one's pressure will be lowered since the system cannot be controlled head by head.