Increasing mowing heights generally increases water-use rates.

• A. True
• B. False
• C. Only for warm-season grasses
• D. Not affected by mowing

Answer: (A)

The main idea here is how mowing height changes the canopy’s leaf area and how that affects water loss. Increasing mowing height leaves longer blades, which increases the canopy’s leaf area and surface area available for transpiration. Even though taller turf can shade the soil and cut down some soil evaporation, the extra transpiration from the larger leaf area tends to raise the overall evapotranspiration, so the water-use rate goes up. This tendency is seen across common cool-season and warm-season grasses under typical conditions, though the exact amount depends on species and climate. The other options don’t fit because the effect isn’t limited to warm-season grasses, mowing does impact water use, and it isn’t generally true that water use decreases or is unaffected.