With very few exceptions a healthy lawn need not be watered more than once a week. When it is watered, however it should be thoroughly drenched to encourage its’ roots to grow deep. The idea is to saturate the entire root zone to a point even past (lower than) the desired root zone. Watering more frequently simply encourages the roots to develop closer to the surface where they will dry out during a hot spell. Another reason not to cut short is that the more growth there is above the ground, the more it literally shades its’ own root system. You’ll rarely see more plant tissue below the surface than above it, still another reason not to cut too short – something many of us humans don’t appreciate.
The more growth above the ground, the more roots. Contrary to popular belief your grass will not “die” from a lack of water like most plants do, it simply goes dormant in much the same way it does in the winter when it’s too cold! Just to confuse the issue, to maintain lush green growth throughout even the dry seasons a light watering –only ten minutes or so about mid day – can be helpful. In much the same way us humans appreciate a light sprinkling on a real hot day a “refresher” or – better yet – stress relief. The idea would be to replace no more than half the moisture lost to transpiration. Another benefit to this light sprinkling is chinch bugs hate water – especially the cold water that comes out of the tap in early summer. It is very important however to ensure that the foliage has time to dry before sundown to reduce fungus and disease development. The best time to water is early morning when the grass is already wet with dew and evaporation rates are low. Watering is never recommended in the evening!