Typical Water Usage to Irrigate Turf Grass

How Much

• Most grass types need 1 to 1-1/2 inches of water a week to survive the summer months. During dry spells or when the grass displays signs of water stress, gardeners must supply this water through irrigation. Signs of water stress includes grass blade discoloration, folded blades and grass browning. Test your lawn by walking across the grass. If your footprints are visible a few hours later, your grass is suffering from lack of moisture.

How to Measure

• Measure the amount of water that your lawn receives through the irrigation system. Set out tuna cans throughout the lawn and turn on your irrigation system on. Measure the amount of water accumulating in the tuna cans to find out how long you need to run your irrigation system. For example, tuna cans that fill up with 1/4 inch of water in 15 minutes need to run for an hour to give your lawn enough water.

Watering

• Water your lawn in the morning when there is still dew on the grass blades. By watering when temperatures are still cool, you prevent water evaporation. In addition, watering at night may encourage disease. Cool nighttime temperatures combined with wet grass blades raises the risk of fungal spore germination. Monitor your irrigation to ensure that sprinkler heads are facing towards the lawn. Watch for pools of water forming on the turf. Certain soils are unable to absorb 1 inch of water at one time. You may need to water twice a week with 1/2 inch of water.

Other Factors

• Raising the mowing height of your lawn keeps grass blades moist. The higher the grass the more moisture is retained. Keep your lawn 3 inches high during the summer to help prevent wilting. Distribute grass clippings evenly over the lawn to contribute nitrogen to the lawn. Avoid applying nitrogen during the summer to cool season grass types. Cool season lawns typically go dormant during the heat of the summer. Allow your cool season lawn to naturally go dormant and grow back in the early fall.