With this pre-simulated 'Spring Fever' there is a real risk in starting up your sprinkler system too early.
As you know, here in Pueblo West, we can get snow in mid-April with below 30 degree nights. Sprinklers get damaged when water is in the pipes and it’s cold enough for water to freeze, which is why your system goes through winterization. You can run the risk (and the expense) of having your lines, sprinkler heads and backflow preventer freeze if we get more cold nights in the forecast. The ground in the spring is still cold from the winter. The ground in the fall is still holding the heat of the summer, so it’s safe to leave your system operational for a little bit longer in the early fall. However, with the colder ground in the spring, you run the risk of damaging your system.
The best indicator of when it’s safe to turn your sprinklers on again is to download a weather app on your phone or check 10-day forecasts online. Keep checking nighttime temperatures and make sure we’ve reached a few weeks period in which the temperature haven't dropped below freezing at night.
If you choose to start your system prior to the last frost, make sure you take precautions if the temperature dips below freezing. You can wrap your backflow with old blankets or towels and then cover with a plastic bag – or you can purchase an insulated backflow cover.