How often should you winterize the irrigation system?

Why it matters

Water left in irrigation lines freezes and splits pipes, valves, and backflow preventers underground where you can't see the damage until spring.

How to do it

Shut off the irrigation supply and drain the zones — or have the system blown out with compressed air, which is the only sure method in cold climates.

Signs you've waited too long

A zone that geysers or dribbles at spring startup means a split line from last winter.

Same part of the house