Homeowners who can’t water in the mornings before work should do it on a weekend morning. We recommend the best time is early in the morning: 4 a.m. to 10 a.m.
Watering during the heat of the day is not the most efficient time for the plant to be watered. Although it can cool the plant, it is not recommended because much of the water would be lost through evaporation before it has had a chance to be taken up by the grass plants. On established lawns, deep, infrequent watering is important in encouraging deeper rooting of the grass plants. Watering at least 1″/week, rather than light infrequent watering, will allow a good soaking of the turf area.
As for frequency, clay soils should be watered once a week and sandy soils about every three days. You definitely don’t need to water your lawn like you water their landscape plants. Most people think more water is better. But it’s not.
Too much watering can lead to fungus growth and even a shallow root system; fewer waterings will help the roots to grow deeper.