When you see signs of drought stress in the grass.

Agree

Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.

Thanks! I should have prefaced that i do know the art of watering, i just was curious when to start it. I have the Rachio irrigation unit and app (highly recommend) and fine tuned it so i know exactly how much per zone and have a very OCD schedule set up ha.

We actually had one of our Kansas City lawn coaches write on this last year- https://www.heritagelawnskc.com/blog/early-spring-secrets-for-the-perfect-lawn/. This goes over pre-emergent for weed control and dormant oil for shrubs also. We wish you a great Spring/Summer lawn this year!

I almost never have to start the irrigation until well into May. That said, I think it's good to fire it up earlier so all the sprinkler heads can pop up easier in the moist turf. I have Rachio also and think it does a fine job after you tweak it to your lawn specs.