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, thriving in northern temperate climates with cold winters and moderate summers.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Midnight type (dark green, dense, fine-textured selection)
About This Grass
Forms a dense, high-quality turf with a rich, medium to dark green color. Height ranges from 1.5 to 2.5 inches when maintained as a lawn, but can reach 18-24 inches if unmowed. Texture is fine to medium, creating a lush, carpet-like appearance.
Blade Characteristics
Medium-fine width (2-3 mm), flat or folded shape, distinct boat-shaped tip, dark to medium green color, folded in the bud (vernation), prominent parallel veins with a tramline effect, membranous ligule, and no auricles.
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes. Tends to form a moderate thatch layer over time. Slow to establish from seed, but has excellent wear recovery through rhizome spreading.
Growing Information
Origin Region
Europe and northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod with underground runners
Sunlight & Water Needs
Requires full sun (at least 6-8 hours of direct sunlight) for optimal performance, with poor shade tolerance. Moderate to high water needs; goes into summer dormancy (turning brown) during severe drought, but revives when watered.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches height. Requires a medium-high maintenance level, including regular fertilization (3-4 lbs N per 1000 sq ft per year), periodic dethatching, and core aeration.
Special Characteristics
Excellent wear and traffic tolerance due to rhizomatous spread. Recovers well from damage. Moderate disease susceptibility (e.g., dollar spot, leaf spot, summer patch). Poor salt tolerance.
Ecological Information
Introduced to North America by European settlers. Provides good erosion control and dense soil stabilization due to its extensive sod-forming rhizomes. Frequently blended with Perennial Ryegrass and Fine Fescues.