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: Thursday, October 24th
- Conditions: The weather is cooler with periods of rain and shorter daylight hours.
- Watering Recommendation: It’s time to stop watering and let your plants go dormant. Autumn is the season when lawns go dormant and look brown. Perennial plants lose their leaves. Add a deep layer of arborist woodchips to the surface of the soil around perennials, shrubs and trees. Adding woodchips to the soil will reduce evaporation as it warms up next spring and summer.
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.
Weekly watering advice straight to your inbox
Sign up for the Weekly Watering Advice Email. We’ll send you a short email once a week with our watering advice and tip between April and October each year.