If you don’t have a soil moisture probe, some simple guidelines can help you decide when to water. Water when grass changes from a green to a grayish blue color, when grass leaves begin to roll, when the grass stays down after being walked on, or when you can’t easily push a screwdriver down into the soil a half foot or so. Apply 1/4 in. of water and then check to see if the soil is wet down to 6 in. If it isn’t, make another application just so the soil is moist, but not wet or sticky.