Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Pooideae, Tribe Poeae
Grass Category
Lawn/Turf, Sports Turf, Golf Course
Variety / Cultivar
Common or 'Midnight' type (based on dark green hue and medium density)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the deep South (Zone 8+).
About This Grass
A dark green, medium-textured grass with a distinct lawn-like uniform appearance. It grows up to 12-24 inches when unmowed. During dormancy (heat/cold), it may turn brown but remains resilient.
Blade Characteristics
Blade width 2-4mm (medium), folded in the bud; unique boat-shaped tips; smooth upper surface with two clear lines (mid-vein) down the center; ligule is short and membranous; auricles are absent.
Root System
Moderately deep, highly fibrous with extensive rhizomes. Forms heavy thatch over time but provides excellent sod strength and recovery capabilities.
Growing Information
Origin Region
Native to Europe, Asia, and North Africa; widely naturalized in North America and cool temperate regions
Growth Habit
Rhizomatous (spreading underground via rhizomes), forming a dense sod system
Sunlight & Water Needs
Full sun preferred (needs 6+ hours); moderate shade tolerance. High water requirements; enters dormancy during severe drought to survive.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; frequent mowing needed during spring/fall; 2-4 lbs N per 1000 sq ft annually; high maintenance level requiring periodic aeration.
Special Characteristics
Exceptional wear tolerance and self-repairing ability through rhizomes; high salt sensitivity; susceptible to leaf spot, rust, and necrotic ring spot in humid conditions.
Ecological Information
Introduced/Naturalized status; provides forage for livestock and seeds for birds; excellent soil stabilizer for erosion control; often blended with Perennial Ryegrass or Fine Fescue.