Irrigation Root Zone & Sod Specifications

Much like the human body, turfgrass is made mostly of water. In fact, approximately 75 percent of a lawn's weight is purely water. When you lay new sod down, however, it is critical to keep the soil moist for healthy root establishment and foliage development. Over and under watering your root zone often causes significant dieback and potential sod failure if not corrected immediately.

Turfgrasses are divided into warm- or cool-season varieties. Warm-season grasses, such as St. Augustine (Stenotaphrum secundatum), hardy in U.S. Department of Agriculture plant hardiness zones 8 through 10, enter dormancy in the fall and winter. In contrast, cool-season varieties, such as tall fescue (Festuca arundinacea), preferring USDA zones 3 through 8, turn brown during their dormant spring and summer rest periods. Choose a sod specified with a healthy mixture of both warm- and cool-season grasses to create a green hue almost year-round. Unless noted otherwise, you can establish most turfgrasses through sodding rather than seeding.

Lay your sod during its most active growing period, typically during spring or fall based on the sod's variety mixture. Your yard should be relatively level for the sod to adhere evenly to the soil below. Remove any hills or low-lying areas by dragging a rake across the ground to create a flat surface. Any ground contours show through after sod installation. On a mild day, lay your sod out on your lightly watered yard and move a lawn roller across the sections. The roller's weight causes the sod's roots to enter the soil irrigation zone for proper establishment.

Although your soil is moist, irrigate your newly sodded area after installing the sections. Using a soil moisture meter pressed into the soil at multiple locations, verify that the water reaches to a minimum 3-inch depth. Depending on your local climate, maintain this moist soil environment by watering twice a day or more. Roots actively take up the moisture to slowly establish themselves in the ground. Dry conditions cause significant dieback and failed adhesion to the soil. Avoid excessive evaporation by mainly watering in the morning.

After approximately two weeks, reduce your watering sessions to once or twice a week. Your irrigation root zone should now be down to a 6-inch depth. Watering deeper than 3 inches down forces grass roots to follow the moisture. As they dive deeper, they spread longer and wider for better nutrient, oxygen and moisture uptake. Roots that remain shallow often die back from drought conditions. Your watering frequency depends largely on your local climate as the grass ages. Observe your grass for any drought issues on a periodic basis. Most healthy grasses have a green or blue hue compared to a thirsty bluish-gray color. Maintaining a moist soil environment encourages healthy grass growth while forcing weeds to die back significantly.