Spring Irrigation Start-Up in Seattle

Hello friends, Mr. Lee here. After a long, wet winter, spring in Seattle brings sunshine, longer days, and waking plants — which means it’s time to turn your irrigation system back on. But don’t rush it. Starting things up the wrong way can lead to broken heads, cracked pipes, and wasted water.

In the Seattle area, most homeowners should plan to start their systems between late March and early May, depending on how wet the ground is and how warm the nights are. Here’s a straightforward guide to help you start up your irrigation system the right way.

Step-by-Step: Spring Irrigation Start-Up

1. Inspect the System Before Turning It On

Walk your property and visually inspect your irrigation components:

Look for broken or cracked sprinkler heads

Check for exposed or damaged pipes

Make sure all valve boxes and backflow preventers are intact

If anything looks questionable, fix it before pressurizing the lines.

2. Slowly Turn the Water Back On

Never open the main water valve all at once. A sudden rush of water can damage the system.

Find the main irrigation shut-off valve

Open it slowly, allowing the pipes to gradually fill with water

Listen for odd sounds — hissing, gurgling, or banging could mean a problem

If you notice any leaks, shut the valve off and inspect the affected area before continuing.

3. Test Each Zone Individually

Turn on one irrigation zone at a time and observe:

Are all the heads spraying evenly?

Are any zones not turning on at all?

Are there low-pressure spots or obvious leaks?

This is your chance to clean or replace clogged nozzles, fix tilted heads, and make sure everything’s running efficiently.

4. Reprogram the Controller

It’s common for irrigation controllers to lose power during winter. Be sure to reset the time and check each program.

Set watering times for early morning to reduce evaporation

Start with shorter run times and adjust as temperatures rise

Make sure rain skip features are enabled if available

If you’re using a smart controller, connect it to Wi-Fi and update weather settings.

Seattle Spring is here!

5. Clean Nozzles and Filters

Winter can cause dirt, moss, and bugs to clog your system. Clean the following:

Pop-up spray nozzles

Drip irrigation filters and emitters

Inline screens, if your system uses them

A clean system runs smoother, wastes less water, and reduces wear on parts.

6. Check the Backflow Preventer

Seattle irrigation systems must have a backflow device to protect drinking water. Inspect for:

Freezing or cracking damage from winter

Missing test tags (you may need to schedule annual testing if required)

Proper valve positioning

If anything looks off or you’re unsure, call a professional — backflow devices are critical.

When Should I Start Up My Irrigation System in Seattle?

Every property is different, but here’s a general guideline:

Late March to mid-April for dry or sunny properties

Late April to early May for shady, low-lying, or wetter yards

Wait until nighttime temperatures are consistently above 40°F

Don’t rely on the calendar alone — walk your yard and check soil conditions before flipping the switch.

Need a Hand?

If you’d rather not worry about any of this, we offer Spring Irrigation Start-Up Services that include:

Full system inspection

Slow, controlled system pressurizing

Head cleaning, adjustments, and repairs

Controller reprogramming for spring watering

Backflow inspection and recommendations

Let us handle the details so your system is ready for the season ahead.

Thanks for trusting us with your yard. If you’re ready to get started or want to combine irrigation start-up with a spring clean-up or mulch installation, give us a call — we’re happy to help.

Mr. Lee