Depending on what the state of your lawn is, two to three times per week for up to 25 mins is for a well-maintained lawn. If you just installed new sod, watering the lawn 4-8 times a day for about 10 mins. After about week 3 of the new sod, water the lawn once per day, anywhere from 15-24 mins. Lawns in Phoenix Arizona usually are established around 3 weeks in.
When you have an established lawn, the proper amount of time to water the lawn is 2 – 3 times a week. A good time to water the lawn is in the morning or during the hottest time of the day.