How Long Should You Run Your Lawn Sprinklers?

Two lawns can run for the same amount of time and receive very different amounts of water. Before copying a neighbor's settings, measure your system. Place several identical, straight-sided containers around one lawn zone. Run that zone for a measured interval, then compare the water collected. Large differences between containers suggest uneven coverage that should be corrected before increasing the whole zone's run time. This catch-can approach helps estimate sprinkler output and identify distribution problems. UC IPM: Lawn Watering (https://ipm.ucanr.edu/home-and-landscape/lawn-watering/) Here is an illustration of the math, not a recommended watering amount: if the containers average 0.2 inches after 10 minutes, the application rate is about 1.2 inches per hour. Delivering 0.4 inches would take about 20 minutes at that rate. Your actual target must reflect grass type, weather, rain, rooting conditions, and soil. Watch what happens during the test. If water begins moving down the driveway before the target amount is applied, split the required time into shorter cycles with time between them for absorption. Rancho Water recommends cycling irrigation for soils and slopes that cannot absorb a long application without runoff. Rancho Water: Irrigation Timers (https://www.ranchowater.com/DocumentCenter/View/6/Outdoor-Water-Use-Efficiency---Irrigation-Timers) Write down the results for each zone. You will have a useful baseline for future adjustments instead of starting from scratch whenever the weather changes.

UC IPM: Lawn Watering — https://ipm.ucanr.edu/home-and-landscape/lawn-watering/ Rancho Water: Irrigation Timers — https://www.ranchowater.com/DocumentCenter/View/6/Outdoor-Water-Use-Efficiency---Irrigation-Timers