Winterize Your Sprinkler System
How to prepare your irrigation system for winter weather
Fall is an ideal time for shutting down
Between mid-September and mid-October is the best time for your landscaper to shut down your sprinkler system for winter. You want to make sure the weather has cooled to the point where you no longer need to run your sprinkler system until spring, yet you don't want to wait too long and risk a freeze.
The sprinkler system is the one part of the landscape that can be totally destroyed by a lack of preparation before winter. In regions where the soil stays frozen for weeks or months on end, irrigation pipes can burst and sprinkler heads shatter if there is water left in the system to freeze. Landscapers in cold climates offer a fall blowout and spring startup service to prevent problems before they start.
Fall winterization stepsIn fall, your main goals for the sprinklers are to make sure there's no water left in the system, and that any complex moving parts have been removed or protected.
Unplug the timer.
Obviously, all of your hard work removing water from the system will be for naught if your timer comes on again the next morning. Also, as Gerry DuBreuil of Belknap Landscape Co., Inc in Gilford, NH points out, "The timer could be damaged by power surges in winter if left plugged-in."
On vacation homes, turn off the main water valve.
If your landscapers are preparing the property for a winter without you, they will turn off the main water valve at the meter with a manual shut off.
Remove backflow preventer and valves.
"The backflow preventer and valves are all above ground, so need to be removed every winter," says Kyle Ritchie of Milieu Design LLC in Wheeling, IL. "The tiniest bit of water in there can break the moving parts inside."
Protect your pump.
On systems where the water is taken from a well or pond using a pump, you'll need to take steps to protect the pump. "You can put 1 to 2 cups of RV anti-freeze into the pump to keep it from freezing through the winter," says DuBreuil. "It won't hurt the landscape when it goes through the system in spring."
Blow out the water.
Sprinkler systems in cold climates are installed with outlets so your landscaper can use a commercial compressor to blow every bit of water out of the system. DuBreuil points out how important it is that the system is completely drained. "It could be very costly to repair or replace the entire system."
Spring startup steps"In spring, it's a similar process in reverse," says Joe Markell of Sunrise Landscape and Design in Sterling, VA. "We also check the system to ensure good coverage throughout the landscape."
- Replace backflow preventer and valves.
- Turn on the main water valve, if it was off.
- Set the timer for spring.
- Check the system thoroughly for leaks, broken heads, or heads that may have gotten turned by a snow shovel to where they're not spraying in the right direction anymore.
If your landscaper suspects a slow leak, they may come back a few days after turning the system on to check for soggy soil or other indications of a belowground break.
- Pro Tip: Don't forget to continue adjusting your system throughout the season. "We check the system two to three times during the growing season so we can adjust for each seasonal change," says Markell. As the weather fluctuates, your plants will need more or less water to perform well.
Cost of winterizing a sprinkler system
While the cost varies in price depending on your region, number of zones, and the complexity of your system, the typical cost for the fall blowout and spring startup visits are about $100-$300.
Genevieve Schmidt, contributing writer for Landscaping Network and owner of North Coast Gardening