How Much Should I Water My Lawn?
We often talk with clients about watering lawns (especially this time of year when it’s HOT, HOT, HOT) and the most frequently asked questions related to watering are:
- How often should I water my grass?
- How long should I run my sprinklers?
How often should I water my grass?
The answer to this question is simple: Usually not more than twice per week unless you are establishing a new lawn with sod or seed. More frequent watering may cause problems with your lawn.
Bermudagrass, Centipedegrass, and Zoysiagrass usually will look good and stay healthy with deep irrigation once weekly. Twice weekly would be plenty.
Tall Fescue will certainly need deep irrigation twice per week. Three times may be necessary for Tall Fescue during the hottest, driest weeks of summer, but setting your sprinklers to run three or more times per week regardless of rainfall increases the risk for fungal disease in a Tall Fescue lawn.
Many people water twice a day, every day, every other day, or at least three times per week. If you are one of these people you may be creating an ideal environment for fungal disease and some of the most invasive and hard-to-control weeds.
Some of the most frequently watered lawns that we see in the Wake Forest/Rolesville area have the worst problems with tough summer weeds—namely nutsedge, which thrives in persistently moist soil.
Pathogenic fungi also love moisture. They develop on the blades of your grass, and the more frequently you wet your grass the more likely you will be to eventually see a fungal disease, especially if you have Tall Fescue grass.
The too-frequent waterers tend to be those who have automated irrigation systems. In our experience, lawns of clients who have automated irrigation systems are more likely to develop signs of pathogenic fungus and have the worst problems with nutsedge throughout the summer.
How long should I run my sprinklers?
The length of time your sprinklers should run depends on the particular sprinklers you use and the area they are covering.
The answer to this question is not as simple because different types of sprinklers vary in the amount of water they put out in a given amount of time. Sprinkler heads vary in their rate of output and range of motion.
Here’s how to determine how long to run your sprinklers.
Put out a few soup bowls around your lawn. Then run your sprinklers to see how long it takes to fill them with a certain amount of water. Bermudagrass, Centipedegrass, and Zoysiagrass lawns will thrive on 1″ of water per week through the summer. Tall Fescue lawns need about 1.5″ of water per week.
If you have an automated in-ground irrigation system, be sure to put bowls in the various zones of the system. If you use hose-end sprinklers that require adjusting the range of motion for different parts of your lawn, then put the bowls in each area as you water.
The best practice for lawn irrigation is to measure rainfall and manually run sprinklers only when needed to supplement rainfall.
Here’s an alternative for those with automated irrigation systems who are too busy to monitor the needs of your lawn:
Consider programming your system to apply about 50-75% of the total amount of water your lawn needs. If rain does not make up the other 25-50% for a given week, then run your sprinklers one additional time to make up the difference.