One freeze is all it takes to turn a minor oversight into thousands of dollars in damage.
As temperatures drop, most homeowners remember to rake leaves and store patio furniture. But many forget the one task that can make or break their landscape come spring: irrigation winterization.
If water remains in your sprinkler lines when the first hard freeze hits, it expands, cracks pipes, and destroys valves, backflow preventers, and sprinkler heads. The result isn't just a repair bill. It's a landscape that goes without water precisely when it needs it most.
Irrigation winterization isn't seasonal maintenance. It's asset protection.
Your irrigation system is a network of buried PVC, brass, and rubber components. Water left inside any of these will freeze at 32 degrees Fahrenheit. As ice forms, it expands with enough force to split pipes, crack fittings, and warp backflow devices.
Spring repairs are expensive, disruptive, and often require digging up sections of your lawn. Worse, you may not discover the damage until you turn the system on and find dry patches where grass is already struggling.
Winterization removes the water before it becomes a problem.
1. Shut Off the Main Water Supply
Locate and close the valve that feeds your irrigation system. This stops new water from entering the lines during the blowout process.
2. Drain the Backflow Preventer
Open the test cocks and valves on your backflow assembly to release trapped water. Leave them at a 45 degree angle to allow any residual moisture to escape.
3. Blow Out the Lines with Compressed Air
Attach an air compressor to the system and blow out each zone individually. Air pressure should stay below 50 PSI for PVC systems to avoid damaging pipes. Run each zone until only mist exits the sprinkler heads. This step is critical. Any remaining water can pool in low spots and freeze.
4. Insulate Above Ground Components
Wrap backflow preventers, valves, and exposed pipes with insulation tape or foam covers. Even after blowout, condensation and temperature swings can cause damage.
5. Program the Controller
Set the timer to off or standby mode. Some controllers have a dedicated rain or winter setting. Remove batteries if the unit won't be used for months.
6. Document and Inspect
Note any heads that didn't pop up, leaks you spotted, or zones that seemed weak. Winterization is the perfect time to flag repairs for spring activation.
Anyone can shut off a valve. Prime landscaping winterization is systematic and precise. It means using the correct compressor pressure for your pipe material. It means blowing out each zone long enough to clear every low point. It means inspecting components for wear while the system is pressurized, catching issues before they become emergencies.
Professionals also understand local codes. Some municipalities require specific backflow handling or certified winterization for warranty compliance. DIY efforts rarely account for these details.
If your system is large, complex, or includes mixed pipe materials, professional winterization is worth every dollar. A prime landscaping team brings commercial grade compressors, zone by zone expertise, and the insurance to cover any rare mishaps.
More importantly, they pair winterization with a full system health check. You don't just survive winter. You enter spring with a clear repair plan and a system ready to perform.