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 lawn-type cultivar (possibly ‘Midnight’ or ‘Baron’ based on dark hue and density)
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor heat tolerance in deep south; goes straw-colored during summer drought/winter cold.
About This Grass
A dark green, medium-to-fine textured grass with a lush, uniform appearance. It reaches 6-12 inches unmowed, producing panicle-type seed heads. Maintains a vibrant green through spring/fall, often going dormant in extreme heat.
Blade Characteristics
Blade width 2-4mm (medium); flat or slightly folded shape; distinctive boat-shaped (keeled) tip; dark emerald green color; folded vernation; membranous ligule; no auricles.
Root System
Moderately deep fibrous root system supported by aggressive rhizomes. High thatch tendency; moderate establishment speed from seed; forms heavy, durable sod.
Growing Information
Origin Region
Native to Europe, North Asia, and mountains of Algeria and Morocco; widely adapted to temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, tight sod over time
Sunlight & Water Needs
Full Sun preferred (>6 hours); moderate shade tolerance. High water needs (1-1.5 inches per week); moderate drought tolerance through dormancy; prefers well-drained soil pH 6.0-7.0.
Mowing & Maintenance
Ideal height 1.5-3.0 inches; weekly frequency; requires 3-5 lbs Nitrogen per 1000 sq ft/year; periodic dethatching/aeration needed (yearly or bi-yearly); high maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot, melting-out, and necrotic ring spot; high aesthetic value for home lawns and sports fields.
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization; used in mixes with Perennial Ryegrass and Tall Fescue for disease resistance and diversity; supports local insect life.