Weekly Watering Schedules

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The amount of water your plants need and when it is needed changes with the weather, length of day, and root depth. By regularly adjusting the watering schedule of your automatic irrigation system (unless you have a smart timer), you can maintain healthy, beautiful plants and avoid wasting water.

In the Pacific Northwest, the watering season typically lasts from April through September. Check this page for advice on programming your sprinkler timer for the upcoming week. Interested in receiving weekly watering advice straight to your inbox? Sign up for the weekly water advice email! From March to October, we’ll send you a short email once per week that includes our watering advice and tips.

Weekly watering advice (resumes March 2026)

Last updated: Friday, October 31, 2025

Conditions: It’s cooler, daylight hours are shorter, and there’s a lot of rain coming this weekend

Watering recommendation: Stop watering established plants for the season 

Mark Guthrie, Landscape Water Efficiency Program Manager

We’ll see you in March!  

This is the last weekly watering advice you’ll receive from Mark until March. Take this 60-second survey to tell him about your experience! 

It’s been a great gardening season! I’ve shared many tips to help you use water more efficiently in your landscape and garden – from building healthy soil to choosing the right plants, to using mulch and optimizing your sprinkler system. It was a lot to cover!  

Share this email with friends and neighbors and invite them to sign up for weekly watering advice on this page. We’ll see you in March! 

Need help winterizing your sprinkler system? Check out this short list of certified local landscape professionals!  

Are you ready to replace your old sprinkler timer with a new weather-based sprinkler timer? Weather-based timers can reduce your landscape water use by up to 25%. You may be eligible for up to a $100 rebate! Learn more about the program and eligibility requirements.  

Do you need professional assistance? Check out this short list of local certified landscape professionals

Choosing the right run time for your system

Each watering should apply a ½ inch of water. The application rate of a sprinkler system depends on the water pressure, system design, and system efficiency. Below are some general ranges of typical run times based on the precipitation rate of your sprinkler heads:

Head Type Nozzle DescriptionRun Time* for a ½ inchIf Using Cycles**
Shows a sprinkler head spraying water in a wide, flat, fan-shaped stream. Spray Head Sprays like a fan 15-23 minutes3 cycles of 5-8 minutes
Rotor Head Single spray that rotates 30-75 minutes3 cycles of 10-25 minutes
MSMT Head Multiple single sprays that rotate 50-75 minutes3 cycles of 17-25 minutes
*Run times calculations: Each sprinkler nozzle type has a specific precipitation rate measured in inches per hour. Spray nozzles operate between 1.3 and 2 inches per hour. Rotor nozzles operate between 0.4 and 1.0 inches per hour. MSMT nozzles, or multi-stream multi-trajectory nozzles, operate between 0.4 and 0.6 inches per hour. From these ranges the runtimes were calculated to water a ½ inch.

**Cycling Recommendation:To prevent runoff and ponding in areas with clay soils and/or slopes, divide the run times into three cycles to allow the ground to absorb the water. Additional cycles are created by utilizing more than one start time combined with shorter runtimes. 

 

If you have drip irrigation, follow these guidelines that include how many minutes it takes to water ¼ of an inch:

View the LTLDL-Techline® DL Dripline Brochure for more information.

More information