Winterizing your lawn sprinkler system can eliminate costly repairs and headaches in the springtime. Water left in the pipes of your sprinkler system can freeze when temperatures dip causing damage to the entire system. Winterizing your lawn sprinkler system involves removing any water from the pipes so they cannot expand and cause damage when freezing temperature hit. Sprinkler winterizing is often called blowing out the sprinkler system or irrigation blow out. When should you turn off your sprinkler system and have us blow out the sprinklers?