Watering slow and deep but not too often is the key to a strong and deep root system. By contrast, frequent, short watering encourages roots to stay shallow, in a zone that dries out faster. Texas A&M recommends applying one inch of water once a week or less, on your chosen watering day. You can measure this by setting out a rain gauge or a tuna fish can. If you find water running off into the gutter before you get one inch (likely) then you need to break your watering into two or three applications on the same day (Learn more: Cycle Soak Method of Lawn Irrigation) The second watering and third watering will push the water down deeper into the soil, to help grow a deeper root system. Remember, shallow watering every few days forces the roots to rise to the surface where the moisture is. Shallow roots demand more watering and make for a weaker plant.
Newly planted trees, shrubs and grass will require more frequent watering since they do not have an extensive root system. Annual flowers and vegetables require more also due to their limited root system. So start now, and water slow and deep to maintain that beautiful lawn and landscape for the summer with minimal care.