During this establishment period, plants can be gradually weaned to a smaller amount of water. Of the tremendous amounts of water applied to lawns and gardens, much of it is never absorbed by the plants and put to use. Some water is lost to runoff by being applied faster than the soil can absorb it, and some water evaporates from exposed, unmulched soil before it can be used by the plant. Yet the greatest waste of water is when too much is applied too often. More plants are killed by too much water than by too little.
Most lawns receive twice as much water as they require for a healthy appearance.
It is best to not water by the calendar, for example, once a week. It is better to water when the plant needs watering. Most gardeners can readily recognize lawn stresses due to lack of water, such as wilting and yellowing. The key to watering lawns is to apply the water as infrequently as possible, yet thoroughly. As with lawns, trees and shrubs should be watered infrequently as possible, yet thoroughly.