Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf
Hardiness Zones
USDA Hardiness Zones 3 to 7, excellent cold tolerance, struggles in extreme summer heat unless irrigated, suitable for the northern and transition zones.
Grass Family
Poaceae, subfamily Pooideae
Variety / Cultivar
Common blend (e.g., 'Midnight', 'Bewitched')
About This Grass
Forms a dense, high-quality turf with medium-fine texture and rich dark green to blue-green color. Matures up to 18-24 inches if left unmowed but typically maintained at 1.5 to 2.5 inches. Produces open, pyramid-shaped panicle seed heads in late spring.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded shape with characteristic boat-shaped tips. Vernation is folded in the bud. Color ranges from dark green to blue-green with prominent parallel veins and two clear translucent lines alongside the midrib.
Root System
Moderate to deep fibrous root system with extensive aggressive rhizomes. High thatch-forming tendency under high maintenance. Slow to moderate establishment speed from seed, but forms an extremely tough, dense sod once mature.
Growing Information
Origin Region
Europe and Northern Asia; widely cultivated across North America and cool temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via aggressive underground stems to form a dense turf
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for best performance, with poor tolerance for deep shade. Moderate to high water needs; goes into summer dormancy under drought conditions but recovers well from the rhizomes once moisture returns.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Medium to high maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft per year), regular watering, and periodic dethatching and core aeration.
Special Characteristics
Excellent wear tolerance and recovery due to aggressive rhizomes. Moderate heat and drought dormancy. Good cold tolerance and winter color retention compared to warm-season grasses. Frequently blended with perennial ryegrass and fine fescues.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome network. Can have minor invasive tendencies in native prairies but primarily used as a cultivated turfgrass.