The temperature range at a 2-inch soil depth for optimal top growth of cool-season turfgrasses is:

The temperature range at a 2-inch soil depth for optimal top growth of cool-season turfgrasses is:

• A. 60-75 F
• B. 50-65 F
• C. 75-90 F
• D. 65-80 F

Answer: (A)

Cool-season turfgrasses grow best when the soil at a shallow depth is in a moderate, cool range. At about 2 inches, a soil temperature of roughly 60–75°F provides the most favorable conditions for rapid top growth because the enzymes and metabolic processes driving growth operate efficiently without triggering heat stress. Temperatures below 60°F slow growth significantly, while temperatures above 75°F begin to slow growth and can increase stress, so 60–75°F is the optimum window for vigorous top growth.

Cool-season turfgrasses grow best when the soil at a shallow depth is in a moderate, cool range. At about 2 inches, a soil temperature of roughly 60–75°F provides the most favorable conditions for rapid top growth because the enzymes and metabolic processes driving growth operate efficiently without triggering heat stress. Temperatures below 60°F slow growth significantly, while temperatures above 75°F begin to slow growth and can increase stress, so 60–75°F is the optimum window for vigorous top growth.