How often should you winterize your irrigation system?

Skipping it eventually leads to water damage or an expensive repair.

Staying on schedule matters beyond the repair bill: a consistent maintenance record is one of the factors in a home's Roots Home Health Score, and well-kept homes typically sell faster and closer to asking price.

How to do it

Water left in irrigation lines and the backflow preventer freezes and cracks the pipes, valves, and the expensive backflow assembly. Blowing the system out before the first freeze prevents that.

1. Shut off the water supply to the irrigation system.
2. Drain the mainline, or in freeze climates blow it out with compressed air zone by zone until the heads spit only air.
3. Insulate the backflow preventer and above-ground valves, or drain them per the maker's instructions.
4. Set the controller to the off or rain season mode.

Alternatives & optional extras

• Air blow-out needs the right (low) pressure and volume; too much pressure damages heads, so many owners hire this out.
• Manual and automatic drain valves handle some systems without compressed air; know which type you have.

Time: 45 minutes · Typical cost: Free with the right compressor; $75–$150 for a pro blow-out

If you skip it

Water frozen in the lines and backflow preventer cracks pipes, valves, and the costly backflow assembly.

Other irrigation / sprinklers maintenance

• Spring irrigation startup and head check — once a year, ideally in April

Related systems to keep on schedule

• Deck / patio — start with: inspect deck ledger, fasteners, and boards, once a year, ideally in May
• Pool / spa — start with: clean pool filter, once a month
• Fence — start with: inspect fence posts and boards, once a year
• Driveway — start with: seal driveway cracks, once a year, ideally in June