Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common blend, typically featuring resilient turf cultivars like 'Midnight' or 'Compact', known for deep green color and aggressive spreading.
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7. Excellent cold tolerance, goes dormant in extreme winter freezes, struggles with prolonged summer heat in deep southern regions.
About This Grass
Forms a rich green, fine-to-medium textured dense turf. Reaches 18 to 24 inches if unmoved, but maintained at 2 to 3 inches. Features boat-shaped leaf tips and pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium-fine blades (2-4mm wide) with flat or folded shape, distinct boat-shaped tips, dark to medium green color. Folded vernation in the bud with a short, membranous ligule and absent auricles.
Root System
Moderate to deep fibrous root system with strong rhizomes. Establishes slowly from seed, but forms a dense, durable sod once mature with low-to-moderate thatch tendency.
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 to partial shade (minimum 4-6 hours direct sunlight). Moderate-to-high watering needs, goes dormant during severe summer drought and greens up with moisture. Prefers well-draining, fertile loamy soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during peak spring/fall growth. High maintenance level with 3 to 5 lbs N per 1000 sq ft per year fertilization schedule.
Special Characteristics
High traffic and wear tolerance due to aggressive rhizomatous recovery. Moderate shade tolerance. Prone to certain diseases like dollar spot, leaf spot, and summer patch under stress. Excellent winter color retention compared to warm-season grasses.
Ecological Information
Introduced species in North America. Provides good soil stabilization, erosion control, and moderate wildlife value for foraging birds and small mammals. Frequently blended with perennial ryegrass and fine fescues.