How much water does my lawn need? (ASK Around)

Getting water right is one of the most common issues homeowners struggle with in their yards. How can you know if your lawn is getting enough—or too much?

A healthy lawn doesn’t need constant watering, but it does need the right amount at the right time. For most homeowners, a good rule of thumb is about 1 to 1.5 inches of water per week, including rainfall. That usually means watering deeply (often 20-30 minutes) once or twice a week, rather than a little every day. However, you might need to adjust the amount for your specific situation, since soil, grass type, and climate each play a role in how much supplemental water your lawn needs.

Soil properties

The texture of the soil under your lawn affects how water moves and how long it stays available to plant roots. Sandy soils drain quickly, so they need more frequent watering. Clay soils hold more water for longer time periods, so they require less frequent watering. However, they also absorb water quite slowly, needing more gentle irrigation to avoid ponding and runoff. Loamy soils are the ideal mix of sand, silt and clay, so they hold moisture well while still draining sufficiently.

Soil structure shapes growing plant roots as well as soil water movement. Deep topsoil with good aeration allows grass roots to grow farther down, increasing access to the soil’s moisture storage between waterings. In contrast, shallow or compacted soils limit root growth, translating to your lawn drying out faster and needing more frequent watering. You can encourage deep rooting by watering deeply (more water) less often and by preventing/treating compaction (for example aeration). Over time, these practices can make your lawn more drought tolerant.

 Grass species

Not all grasses are created equal when it comes to water use. Cool-season grasses (e.g. Kentucky bluegrass or fescue) typically need more water to stay green during hot summers. On the other hand, warm-season grasses (e.g. Bermuda, Zoysia, Centipede, and St. Augustine) are more drought-tolerant and can thrive with less frequent watering once established.

As mentioned previously, deep roots are your lawn’s lifeline to water in dry times. Short-rooting grasses (1-8 inches, e.g. Poa Annua and Bentgrass) may need more frequent watering, while deep-rooting (18+ inches, e.g. Zoysia, Bermuda, and Tall Fescue) are often the most resistant to drought.

Climate & environment

Where you live and the current weather conditions are probably the biggest factors determining how often your grass needs to be watered. Lawns in hot, dry regions or exposed to full sun will need more water than those in cooler, humid climates or shaded areas. Wind, slope, and nearby trees can also affect how quickly your lawn loses moisture. Observation is key. A standard watering schedule and timed sprinklers are an excelling starting point, but the most important thing is to pay attention to your lawn to notice if it’s too dry, if it’s too wet, or if moisture is uneven for any reason. Waiting too long until your grass is totally dry and brown will just lead to a dormant lawn, but you can check for earlier signs like a dull blue/purple color or footprints that linger. In contrast, grass blades with adequate moisture show flexibility and spring back when disturbed, indicating it’s not yet time to water again.

With a little observation and adjustment, you can keep your lawn healthy while using water efficiently, benefiting both your yard and your wallet.

Click here for more lawn watering tips from SoilKit or click here for even more details from Kansas State University.

What about watering gardens? Click here to learn more.