Water Efficiency Tips: Watering and Maintaining a Green Lawn


On average, we use approximately 50 percent more water in summer and some community water systems in New Hampshire have even reported a whopping 100 to 200 percent increase in water use during this time. This leap in demand comes at a period when water resources are already most stressed due to high temperatures and increased demand from vegetative growth; therefore, it is important that we maintain a careful balance between our needs and the needs of nature to ensure the availability of enough clean water into the future. While we use water outdoors for many purposes such as washing cars, patios, and siding, playing on slip’n’slides, and filling pools, the majority of outdoor water use can be attributed to outdoor watering of lawns and landscapes. Experts agree that much of this water is wasted due to inefficient watering practices. The good news is that experts also agree that we have the potential to cut our outdoor water use in half, saving money, water, and energy, while potentially even increasing the health of our lawns. By giving your lawn only what it needs you will actually improve the durability of grass, reduce the need for chemical amendments, and decrease lawn mowing frequency.

Stay sharp.

  • Raise your lawn mower blade height to three inches. Longer grass blades retain moisture better, keep weeds to a minimum, and encourage roots to grow deeper and stronger.
  • Keep the mower blades sharp. Mowing with a dull blade gives grass a “split ends” look making grass seem drier than it is.

 Maintain control.

  • Water deeply and infrequently to encourage deep, strong root systems.  New Hampshire receives on average of 3.75 inches of rain per month. Your lawn and landscape need no more than 1 inch of rain per week, so there will be periods when your lawn requires no watering. When supplemental watering is necessary, watering just enough is imperative. Too much or too little water can inhibit root growth and make grass more susceptible to dry conditions, while too much water can also lead to fungal diseases and wash away important nutrients.
  • Replace your irrigation system’s clock timer controller with a WaterSense-certified weather-based irrigation controller and soil moisture sensor and you are guaranteed to save. Weather-based irrigation controllers and moisture sensors ensure your system is set to give your landscape the optimal amount of water. Learn more about WaterSense-certified controllers and irrigation companies at
  • Install an automatic rain shutoff switch on your irrigation system. These switches allow you to take advantage of the water Mother Nature provides without having to pay for it.
  • Adjust how long you water your lawn each week based on how much rainfall is received. Doing so will ensure a healthy landscape and minimize water waste. Follow the three simple steps below to learn how:
    • Determine the rate of flow from your sprinkler. Place cans (tuna cans work well) at various locations on the lawn. Mark a one-inch depth on the inside of the cans. Time how long it takes your sprinkler heads or hose to deliver an inch of water to each of the cans, and average the times. This is how long you should run your sprinklers or hose to deliver an inch of water. Normally sprinkler heads flow at a rate of 1.5 inches to 1.7 inches per hour.
    • Determine how much it rains each week so you can adjust your watering duration accordingly. This is easily done by placing a rain gauge in your yard and checking on it once a week, maybe on trash day. Rain gauges can be purchased for a few dollars at your local hardware or garden store. Subtract the height of water in the rain gauge from 1 inch. If you get a negative number, you do not need to water. If you get a positive number, this is how much water your lawn needs.
    • Multiply the inches of water needed by the number of minutes it takes your system to water 1 inch and that will indicate the length of time to run your sprinklers. Empty the rain gauge and repeat this process again in a week.

Watering Duration (Minutes) = (1 inch – X) * Y

X = Weekly Rainfall received at rain gauge

Y= Number of minutes it took to fill can to one inch

  •  Utilize drip or trickle irrigation instead of spray nozzles for landscape plantings. These systems apply water near the root zone of the plant, ensuring a complete watering while reducing excess water usage.
  • Use mulch around vegetated areas. Mulch helps to retain moisture and keep weeds out.
  • To learn more about appropriate fertilization and drought resistant seed types go to the Home and Garden page on the University of New Hampshire Cooperative Extension website.

 Time it right.

  • To reduce water waste from wind and evaporation, irrigate between 9 p.m. and 9 a.m. and when it’s not windy.  Even better, irrigate between 4 a.m. and 6 a.m. when water demand is low.
  • If you notice water running off vegetative surfaces you are either over watering or not allowing enough time for water to absorb. If your soils are clayey or you are watering on a steep slope, it may take additional time for water to absorb into the soil requiring watering times to be cycled. For example, set your irrigation controller to water at five minute intervals.

A Home Water Efficiency: Lawn Watering and Maintenance Fact Sheet is available in pdf for easy printing.

A Home Water Efficiency: In-Ground Irrigation System Fact Sheet is available in pdf for easy printing.