Once your new lawn is installed, you should immediately start watering for 10 to 12 days as the roots knit to the soil. Your watering should penetrate the ground 4 to 6 inches so that a long screwdriver should easily go into the ground.
Immediately after the sod is laid, begin watering all sodded areas. Schedule watering to assure the sod is constantly wet and water penetrates the soil 4 to 6 inches. This should continue for 10 to 12 days until roots knit sod to the soil. The sod layer can easily dehydrate before roots are formed and severe damage can occur to your new lawn. Foot printing and/or the grass blades turning a blue-gray color indicate your sod is under dehydration stress and should be watered.
Once the roots have knitted to the soil, water every 2 to 4 days. However, the frequency and amount of watering depend on the soil type, root depth, topography of the land, natural precipitation, wind, temperature, humidity, etc. It is best to apply water less often but at a rate that penetrates the soil 4 to 6 inches. Lesser amounts applied daily will cause shallow root growth and diminish drought resistance. Check with your sprinkler installer or manufacturer for precipitation rates to assure proper water application.
Winter watering generally should be done every 3 to 4 weeks, depending on weather conditions. This is particularly important if the sod was installed in the fall.