Winterizing your sprinkler system is a must in Central Oregon. With the different sprinkler system setups, piping and air pressures, etc., we suggest letting a professional help. We take the time to ensure the system is fully winterized. This includes:
Further details on the sprinkler winterizing service:
The typical Bend sprinkler system (four zones) costs $70 to blow out and winterize. For each additional zone it costs $5.
We suggest winterizing your sprinkler system no later than December 1st in Bend, Oregon and here is why… According to the Bureau of the Interior, the average low temperature for Bend starts dropping below freezing in September (see the chart below). However the daily average (mean) temp stays above freezing until November. In other words, the potential for freezing ground starts in September (though not likely given the daily avg temp) and as the daily avg temperature drops, the probability of ground freeze increases. Given your sprinkler heads are at ground level, you obviously want to remove any water before freezing if you want to avoid broken sprinkler equipment and costly repairs next year. If you play the averages, your best bet to avoid freezing ground seems to be October through about November 15.
Now, given the elevation change throughout Central Oregon from 2,200 feet in Madras to 4,200 feet in La Pine, the date the ground freezes will fluctuate slightly. Just be sure no water is left in your sprinkler system by the time the ground starts to freeze.