Sprinklers and lawn irrigation systems are beneficial, but they can waste water and actually harm your grass if not used properly. Here's how to figure out how often to water the lawn.
How do you know when to water? Water grass when you see these three signs:
None of these signs indicate that grass is about to die. Turfgrass has the ability to turn brown and go dormant but stay alive for three to four weeks. If you live in an area with water restrictions, it's a good idea to let your grass go dormant between waterings. When you reach the three- to four-week mark without rain, water the grass long enough to moisten the top 5 inches of soil. This keeps grass alive but may not be enough water for the lawn to green up.
Always allow the soil to dry out, and wait until blades begin to wilt before turning on your lawn irrigation system again.
Watering daily or too often not only wastes water, but also clogs the air spaces between soil particles that are needed by the roots of grasses. When grass seed roots can't breathe or grow, or when grass blades are wet for longer than 14 hours, they become vulnerable to a wide variety of diseases and pests.
In general, it's best to water your lawn deeply but less frequently. This practice encourages turfgrass to develop deep roots that sustain it better through periods of drought.
When you water grass, apply about 1 inch of water.
Determine how long it takes your water sprinkler to distribute 1 inch of water by placing several shallow containers in your lawn while running the sprinkler for 30 minutes. Measure the depth of the water in the containers. The average depth times two is the number of inches of water per hour your water sprinkler system emits, so you know how long to run it.
The best time to water the lawn is between 10 p.m. and 6 a.m. to reduce the amount of water lost to evaporation. This is also a lawn's natural dew period.
Keep the mower blade set higher. Grass cut at 3 inches tall retains more water than grass cut at 2 inches.
Determining how much to water the lawn, how often to water, and how long to water are questions you can answer only when you take into account your soil, grass species, and weather.
A healthy lawn needs good soil, just like a garden. Your lawn soil should be well aerated with at least 4 to 5 percent organic matter. If your lawn struggles despite your best efforts, test your soil. Your local Cooperative Extensive Service can assist you.
A wide variety of species can be grown for lawns. Choose the type best suited for your region's weather conditions. Some types are more drought tolerant, thanks to deeper root systems.
Cool, wet weather gives you a break from lawn irrigation tasks. If you have a sprinkler system set on an automatic timer, check it frequently so you can turn it off during times it's not needed.