Irrigating late into the season in the High Desert is sometimes necessary for new landscapes and newly established plantings. For most systems with valves and pipes installed at proper depths it is not an issue to run sprinklers through October and November. Our air temperatures might be freezing at night, but our soil temps are still warm enough to prevent freeze damage to pipes and fittings.
Irrigation controller programming becomes critical if you are irrigating at this time of year. You need to adjust your controller run times and start times to reflect the seasonal change from summer to fall watering needs. It is imperative if your irrigation borders a sidewalk or street that you adjust your start times to avoid creating ice along walkways and roads.