Kentucky Bluegrass
Kentucky Bluegrass is the premier cool-season turfgrass for northern lawns, prized for its rich blue-green color and dense, carpet-like growth. It thrives in cool temperatures and recovers well from wear thanks to spreading rhizomes, but goes dormant and turns brown during summer heat and drought.
Tolerance & Maintenance
How to Identify Kentucky Bluegrass
- ✓Boat-shaped leaf tip — the most distinctive identifier
- ✓Narrow blade width (2–4 mm), fine to medium texture
- ✓Deep blue-green color with a slightly waxy surface
- ✓Grows by rhizomes, forming a dense, self-repairing sod
- ✓Pronounced midrib (light stripe down the center of each blade)
Mowing
Raise to 3.5 inches in summer heat to reduce stress. Never remove more than one-third of the blade at once.
Watering
Water deeply and infrequently to encourage deep roots. In summer dormancy, 0.5 inches every 2–3 weeks keeps crowns alive without fully breaking dormancy.
Fertilization
Avoid heavy nitrogen in summer, which stresses the grass during heat. Fall feeding is the most critical window for root development.
Common Problems
Summer Dormancy
Goes brown and dormant in temperatures above 85°F. This is normal and not disease. Consistent deep watering can keep it partially green.
Dollar Spot
Small tan spots the size of silver dollars, caused by fungal disease in humid conditions. Increase nitrogen and avoid evening watering.
Necrotic Ring Spot
Rings of dead grass 6–12 inches in diameter, caused by a soil fungus. More common in stressed, over-fertilized lawns.
Grub Damage
Sections of turf peel back like carpet due to root destruction by white grubs. Apply preventative grub control in early summer.
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