The amount of water your plants need and when it is needed changes with the weather, length of day, and root depth. Regularly adjust the watering schedule of your automatic irrigation system (unless you have a smart timer) to maintain healthy, beautiful plants and avoid wasting water.
In the Pacific Northwest the watering season usually lasts from April to September. Check this page weekly for advice on programing your sprinkler timer for the upcoming week.
This week’s watering advice
- Updated: Friday, April 18, 2025
- Conditions: The soil is still saturated.
- Watering Recommendation: Don’t water established plants!
Using multiple start times on a sprinkler timer can save water by encouraging roots to grow deeper. Plants with deeper roots need to be watered less frequently.
Use multiple start times when watering plants in clay soils and on sloped areas. For example, instead of watering a lawn in clay soil for 12 minutes, water it three times for 4 minutes and set each start time to begin 30 minutes apart. Watering for fewer minutes at a time allows the water to soak deeper into the soil. The deeper the water moves into the soil the more water is available to long roots and leads to less frequent watering.
Are you ready to replace your old sprinkler timer with a new weather-based sprinkler timer? You may be eligible for up to a $100 rebate! Learn more about the program and eligibility requirements on the Saving Water Partnership website.
Need some 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 Description | Run Time* for a ½ inch | If Using Cycles** | |
|---|---|---|---|---|
 | Spray Head | Sprays like a fan | 15-23 minutes | 3 cycles of 5-8 minutes |
 | Rotor Head | Single spray that rotates | 30-75 minutes | 3 cycles of 10-25 minutes |
 | MSMT Head | Multiple single sprays that rotate | 50-75 minutes | 3 cycles of 17-25 minutes |
**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.
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