Turfgrass Management
What the exam tests
Turfgrass Management covers species selection, mowing, fertilization, irrigation, cultivation, and pest diagnosis for lawns and sports turf.
Core rules
- Cool-season grasses include Kentucky bluegrass, tall fescue, perennial ryegrass, and fine fescues; they grow most in spring and fall. Warm-season grasses include bermudagrass, zoysiagrass, St. Augustinegrass, and centipedegrass; they grow in summer and go dormant after frost.
- Mow by the one-third rule: never remove more than one-third of the leaf blade at one cut. Raise the cutting height in heat or drought.
- Fertilize based on soil test. Typical maintained-lawn nitrogen rates are 0.5-1.0 lb N per 1,000 sq ft per application; avoid summer nitrogen on cool-season grass.
- Irrigate deeply and infrequently, about 1 inch per week including rainfall, to encourage deep roots.
- Aerate compacted soil, control thatch when it exceeds about 0.5 inch, and overseed cool-season lawns in early fall.
Worked example
A 5,000 sq ft tall fescue lawn needs 1.0 lb N per 1,000 sq ft. Total N = 5 x 1.0 = 5 lb. Using 24-0-0 fertilizer, product needed = 5 divided by 0.24 = 20.8 lb. Reasoning: divide the desired nitrogen by the percentage in the bag. Apply in two directions for even coverage and water lightly. If the grass is 4.5 inches tall, mow to 3 inches, removing 1.5 inches, exactly one-third.
Traps
Scalping stresses grass and invites weeds. Fertilizing warm-season grass before spring green-up encourages cold injury. Shallow daily watering produces shallow roots. Weed-and-feed products can injure trees and shrubs if applied over root zones. Do not apply herbicide when temperatures exceed label limits.