June through September. From October through May, minimal lawn watering is usually needed.
Morning hours—from 4 to 8 a.m.—are most efficient. Less water is lost to evaporation in the early morning, temperatures are lower, sunlight is less intense, and there is less wind. Midday watering is less efficient because of evaporation, though it may benefit plants in hot weather since it cools them and reduces stress. Try to avoid watering in late evening-plants may remain wet through the night, encouraging lawn diseases.
Notice its color-if it’s changed from a lively green to a duller, grayer green, your lawn needs water.
Look behind you when you walk across your lawn—if your footprints remain visible, your lawn needs water.
That depends on your soil.
Coffee can method: Place a row of equal-sized, straight-sided cans in a line at 1- or 2-foot intervals from your sprinkler to the farthest point of watering. Time how long it takes to fill the cans 1/2 to 1 inch—that’s how long you should water your lawn.
Spade method: Sink a shovel into the soil and form a hole. Soil should be moist to the depth of the spade. Then remove the shovel and press the soil into place with your foot.
Lawn Care and Water Quality Program
Pesticide & Fertilizer Management Division
Minnesota Department of Agriculture (MDA), 625 Robert Street N, St. Paul, MN 55155-2538, firstname.lastname@example.org