||Evapotranspiration (ET) is a measurement of how much water a plant loses through the soil (evaporation) and through its leaves (transpiration). A warm-season turf grass in full sun, on a hot and windy day, will have a higher rate of ET (and need more water) than grass located in a shady area protected from wind. Texas Agrilife Extension maintains weather stations all over Texas and uses this weather data to calculate ET values for different regions of Texas.|
Getting Started With ET:
Watering requirements are typically given in inches of water. Click here to view watering recommendations for College Station. But how many inches of water does your sprinkler put out in a given time period? Use this simple formula below to determine how much water your sprinkler applies in a given time period:
- Set 3 to 5 empty shallow flat-bottomed cans at different distances from the sprinkler, with the last can near the edge of sprinkler coverage.
- Run the sprinkler for 15 minutes.
- Add the inches of water in all cans and divide the total inches by the number of cans to obtain an average.
- Multiply the average by 4. This is your sprinkler's precipitation rate in inches per hour.
- Typical sprinkler precipitation rates: Multi-stream rotors - 0.3 inches per hour; rotor heads - 0.5 to 0.75 inches per hour; fixed sprays - 1.25 to 1.5 inches per hour
How Often Does Grass Need to be Watered?
Start with one watering day per week, and add another day as needed. For soil with poor drainage, divide long run times into several shorter cycles on the same day. For example, instead of running the sprinkler for 30 minutes continuously, water for 10 minutes, 3 times, with each watering time separated by an hour or more. This will give your grass a deep soaking every time you water. To find out how often to water in the summer, locate your grass type in the table of Watering Frequency for Turf Grass below. Another easy tip is to look for footprints: if you leave footprints on the grass after walking on it, it's time to water. If the grass springs back, just relax and enjoy your beautiful turf.
Watering Frequency for Turf Grasses adapted for College Station*
||Every 2 - 5 weeks**|
||Every 7 - 10 days|
||Every 7 - 10 days|
||Every 5 days|
* Note: Adapted from Texas AgriLife Extension publications.
** Buffalograss may not need supplemental watering at all in many areas of Texas where it is adapted to grow.