Everyone is always anxious to kick-off the warmer spring weather, but don't rush supplemental watering, in fact,  if the weather is mild we hope you wait until June to actually run your sprinkler, but there is nothing wrong with getting it ready! 

Since we are in the Midwest where the weather is fickle, we recommend you don't even think about it until after the 15th of April and not even then if the temperatures are dipping below freezing. We like to have two straight weeks of above 32 at night before you try to start-your sprinkler in the spring, but frankly, there is typically zero need for supplemental watering in April. 

Keep in mind that in order for the water you are putting down to do any good for your grass, the ground temperature needs to be above 50 degrees. At Jensen Sprinkler we are checking the ground temperatures every day until it reaches 55 degrees. If you would like a resource to check that yourself, here is a link to the Iowa State Extension data we use: Four Inch Soil Temperature Maps.