What is involved with winterizing my lawn sprinkler system?
If you have an above-ground backflow preventer, generally you will need to have it removed or otherwise protected from freezing temperatures.
When should I shut down my irrigation system? I just seeded my yard!
Temperatures that may damage your backflow preventer would be well below freezing for several hours at night and chilly (~45°) during the days, given the warmth the ground holds with daily temperatures currently in the 70s or even in the 60s. Your backflow preventer is not likely to be damaged should the night temperatures dip below freezing at this time. You can insulate your backflow to prolong watering your lawn into the late fall/early winter depending on actual temperatures and insulation method you choose. Other factors include the amount of sunshine directly on your backflow per day and elevation within your surroundings, as cold air sinks during calm nights.
Contact us at Laurdane Associates for more information about your specific situation!