Sports Nutritionists tell their athletes just how much they need to drink in order to perform at their maximum and not dehydrate. Your Lawn relies on you to be its Nutritionist and not to dry it out too much. At the other extreme watering a little and often is just as bad for turf health.
So how much is enough? Where is the .05 for Lawns?
At the laying stage turf needs to be kept moist at all times until the roots are long enough to search for water at a deep level in the soil. The initial irrigation should wet the newly laid turf and moisten the soil to a depth of a few inches. Depending on weather conditions you may need to water new turf several times a day to achieve this. Once the turf cannot be lifted reduce the frequency of irrigation and increase the amount applied at each watering. This will get the water down deep and encourage the roots to lengthen and in turn become less reliant on frequency of irrigation.
Warm season grasses such as Sir Walter, Eureka Kikuyu and Nullarbor Couch require very little water once established. Water them as required but ensure it is a deep watering so that the roots don’t shorten. This process of slightly drying the soil profile and then watering deep has the effect of initially creating air pockets that then fill with water when irrigated.
Constantly wet soils become compacted as air is squeezed from them. In turn the lawn grass roots shorten and the turf becomes prone to disease and drought stress in warm dry weather. Moss and algae will also develop on the surface in this situation.
So the key message is once your lawn is established, water it deeply and infrequently. Follow that rule and your lawn won’t become dehydrated and it wont be over .05.