How Often Should a Lawn be Watered?

A lush lawn requires proper watering.

In most areas, watering or irrigation is necessary for a lush lawn. The amount of water used is determined by the frequency and duration of the lawn watering. Proper watering procedures not only keep the lawn green but prevent the waste of water, which can reduce costs of water utilities. Overwatering can lead to disease problems and excessive growth requiring more mowing. The process requires some research and knowledge of the grasses growing in your lawn.

Water as Needed

Lawn grass changes color when it begins to show stress due to a lack of moisture. Physically, the grass leaves also will change shape and not spring back when stepped on, leaving visible footprints in the turf when someone walks across the lawn. Watering at this point provides the minimum moisture necessary to keep the grass growing. Water the lawn until the ground is saturated through the root zone or about 6 inches deep. Once a month, triple the amount of water applied. This provides water to the root zone of any trees or shrubs in the landscape.

Water to Replace Moisture

This process requires some calculations on the part of the homeowner. First calculate how much water is applied during each watering by placing straight-sided containers around the lawn and measuring the accumulated water from a normal duration watering session. Then research the amount of water the lawn uses each day. Bluegrass may require about 1/3 inch of water each day while other lawn grasses are more drought tolerant and require as little as 1/5 inch of water per day. Divide the amount of water applied during a normal watering session by the lawn's water use each day to determine how often to water. For example, if you apply 1 inch of water in each session and your lawn uses 1/4 inch of water per day you should water the lawn every four days.

Allow for Rain

Avoid overwatering by factoring any normal rain into the situation. The rain water delays any problems with grass stress and obviously delays the need to water the lawn for any homeowner following the water as needed procedure. Calculate the number of days of moisture the rain provided and delay the watering by that number of days if you are watering to replace used moisture. Extreme rains -- rainfalls greater than the amount necessary to saturate the root zone -- soak below the roots and limit the effect of the rain on the grass but may aid trees and shrubs.

Water Conservation

Water early in the morning when temperatures are cooler. This reduces the water lost to evaporation and increases the amount soaking into the ground. Avoid watering on sidewalks, driveways or patios. The water runs off these hard surfaces and overwaters the grass in the area.

References

• New Mexico State University; Watering Your Lawn; Lynn Ellen Doxon; 2001
• Virginia Cooperative Extension; Summer Lawn Managment; Mike Goatley; 2009