Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common or various blended cultivars like 'Midnight' or 'Baron'
Hardiness Zones
USDA Hardiness Zones 3 to 7, thriving in northern cool-temperate climates. Excellent cold tolerance, goes dormant in extreme heat.
About This Grass
Forms a dense, fine-to-medium textured turf with a rich green to dark green color. Reaches up to 18-24 inches when left unmowed, but maintained as low as 1.5 to 2.5 inches. Produces characteristic open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are fine to medium in width (2-4mm), flat or folded with distinct parallel veins and characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, and auricles are absent.
Root System
Moderately deep fibrous root system combined with aggressive rhizomes, creating a dense, tough sod. Moderate to fast establishment rate from seed; forms heavy thatch if over-fertilized.
Growing Information
Origin Region
Europe, northern Asia, and parts of North Africa; widely naturalized and cultivated across cool-temperate regions worldwide.
Growth Habit
Rhizomatous, forming a dense, uniform sod through extensive underground spreading stems.
Sunlight & Water Needs
Requires full sun (at least 6 hours of direct sunlight) for optimal performance, with moderate to high water needs. Enters summer dormancy during prolonged drought unless irrigated.
Mowing & Maintenance
Ideal mowing height ranges from 2.0 to 3.5 inches. Requires regular mowing, medium to high fertilization (2-4 lbs N per 1000 sq ft annually), occasional dethatching, and aeration. High maintenance level.
Special Characteristics
Exceptional wear and traffic tolerance due to aggressive rhizomatous recovery, good cold hardiness, moderate shade tolerance compared to fine fescues, and forms a strong erosion-controlling turf.
Ecological Information
Widely introduced and naturalized across North America. Provides good soil stabilization, moderate wildlife habitat for grazing and nesting, and is frequently blended with perennial ryegrass and fescues in turf seed mixes.