The majority of South Carolina has experienced very dry and hot periods of weather as of late and as a result, irrigation systems throughout the state have been running more frequently. It is common to see irrigation systems running throughout the day and even consecutive days. It can shock homeowners to learn that this practice causes greater damage to their yards.
Though it is hot and at times dry during our summers, yards should not be irrigated in the middle of the day. This practice can lead to unnecessary water loss due to evaporation and can magnify solar energy on the plant itself. Instead, irrigate lawns in the morning when there is still dew on the ground, this keeps the plant from staying wet any longer than it typically would, which decreases the chance of disease development.
Lawns require approximately 1 inch of water per week during the growing season. This can be applied as rainfall, irrigation, or a combination of the two. A rain gauge is a cheap and effective way to monitor how much you should actually run your sprinklers. To decrease water usage, you may also select turf species that are more drought tolerant; HGIC 1214, Selecting a Lawn Grass. To determine how much water is being applied, randomly set out straight-sided cans, pans or jars to collect water from irrigation zones. Run the sprinklers as you normally would and then measure and average out the amount collected in the jars. Adjust run times accordingly. For more information see, How to Set and Calibrate Your Irrigation System.
Also, though we may experience the heat multiple times during the week, watering yards every day can actually cause roots of plants to become shallower which causes them to be less drought resistant. Instead, focus on watering your lawn less often but for longer periods of time.
Other tips for watering your lawn can be found at: HGIC 1207, Watering Lawns.