How to Water Your Lawn Wisely

Water conservation and a healthy, beautiful lawn aren't mutually exclusive. You can do your part to manage water usage, and keep your lawn. The Environmental Protection Agency (EPA) estimates that approximately one-third of all U.S. residential water use is for irrigation, but more than 50% of irrigation water is wasted by inefficient use.¹ Whether you're motivated by water restrictions, good stewardship or rising water prices, you can implement simple, water-conserving choices that make sense for you, while at the same time maintaining a healthy lawn.

Understanding Grass Needs

Lawn-water conservation starts with growing the right grasses. When lawn grasses are naturally suited to your local climate, their water needs are in sync with your region's normal growing conditions. As a result, regionally appropriate grasses thrive with less supplemental water and maintenance than grasses less suited for your area. Cool-season grasses, such as Kentucky bluegrass or tall fescue, naturally do best in cool, northern zones, while warm-season grasses, such as Bermudagrass or Zoysia grass, flourish in warmer, southern climes.

Cool- and warm-season grasses respond differently when water is limited. In general, cool-season grasses lose more water through their pores and are less efficient than warm-season grasses in managing water under stress. For example, some Kentucky bluegrasses can use 50% more water per day than Bermudagrass. In some circumstances, the difference may be even greater.²

In addition to differing water usage, lawn grasses vary in drought resistance and drought tolerance. Some grasses avoid drought by retaining more water or growing deeper root systems, others escape drought by going dormant, and still other types resist drought effects by tolerating dehydration well. Growing regionally appropriate grasses increases your lawn's potential to conserve water and retain health and beauty when water is limited.

Growing water-conserving grass varieties, such as those qualified by the Turfgrass Water Conservation Alliance (TWCA), translates to lower water usage, less lawn maintenance and more time to enjoy your lawn. Whether cool- or warm-season grasses, TWCA-qualified varieties have undergone rigorous testing to prove statistically significant drought tolerance over similar grass species.³ Pennington Smart Seed grasses, for example, require up to 30% less water year after year than ordinary grasses, and they stay green for up to three weeks without water.

Watering Wisely Under Normal Conditions

Most lawns need the equivalent of 1 inch of rainfall each week to retain their health and attractive appearance. This includes water from natural precipitation and any supplemental irrigation you provide. Water moves faster and deeper through sandy soils than through clay, but 1 inch of water penetrates about 4 to 6 inches deep in average soils.⁴ That's adequate for grass roots in most normal lawn situations. TWCA-qualified grasses require even less.

Implementing these water-wise watering practices, as part of your regular lawn maintenance routine keeps lawns healthy while cutting down on wasted water:

Use rain gauges or weather data to track how much weekly water nature provides, then supplement only as needed. Too much water prevents roots from getting needed oxygen and encourages many types of lawn disease.
Monitor how much water your sprinkler system provides; don't guess. Set up water gauges or 1-inch-deep cans (tuna cans or cat food cans work well). Measure the sprinkler water you collect in 15 minutes to determine how long it takes to supply 1 inch.
Water your lawn between 4 a.m. and 10 a.m., whenever possible. Early morning watering reduces loss to wind and evaporation, and allows water to soak in before sunlight heats the soil.
Use watering systems that stay close to the ground. Arcing sprinklers waste more water than systems with low trajectories.
Water ordinary grasses deeply once or twice per week, if needed. Shallow, frequent watering leads to shallow, drought-vulnerable roots. Deep, less frequent watering encourages deep roots and improves drought tolerance.
Distribute water evenly and slowly to prevent puddling or runoff, and avoid watering sidewalks or other paved areas. Consider intermittent sprinklers that water briefly, then allow a soak-in period before continuing.

Whatever watering regimen you choose, look to your lawn for the final word. Well-hydrated grass springs back up when stepped on. If grass stays depressed, it may need water. Curled grass blades or dull, blue-gray color are signs grasses are water stressed.

Responding to Drought and Water Restrictions

In drought-impacted areas, limited water and water restrictions demand stricter approaches to lawn care. Even in areas not officially under drought, it makes water-wise sense to look ahead and be prepared. The National Oceanic and Atmospheric Administration (NOAA) reported that nearly 50% of the United States was experiencing abnormally dry to extreme drought conditions as of September 1, 2015.⁵

Always follow all local water regulations that impact lawn maintenance. When conditions call for stricter measures, these water-conserving practices can help drought-stricken lawns survive:

Reduce irrigation gradually over several weeks, instead of all at once. This allows grasses and other landscape plants to acclimate to water shortages.
Adjust watering or irrigation schedules every week to compensate for current weather conditions and changing regulations.
Adjust irrigation systems to reduce or avoid watering areas that receive shade, and keep available water focused on exposed lawn.
Consider smart controllers, which sense soil moisture and automatically adjust irrigation based on current soil and weather conditions, to minimize water use.
Shut down automated irrigation systems during severe shortages, and water critical areas by hand only.
Avoid fertilizing. Fertilizer promotes new growth that requires more water, and stressed lawns are also more prone to fertilizer burn.

Even before drought hits, prepare your lawn by mowing higher than normal recommendations during hot summer months. This helps shade roots and soil, and promotes deeper roots that can draw water from larger areas.