Kentucky Bluegrass
Poa pratensis · Cool-season (C3), Perennial
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Fairway
Variety / Cultivar
Likely an Improved Turf-Type Cultivar (e.g., 'Midnight', 'Mazama', or 'Blueberry')
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters dormancy during extreme summer heat or winter freezes; poorly adapted to the deep South (Zones 8-11) unless at high altitudes.
About This Grass
A dense, low-growing turf grass with a distinct deep blue-green color. It produces a soft, lush texture and is highly valued for its ability to form a thick carpet that recovers from wear due to its rhizomatous nature. When unmowed, it can reach 6-12 inches and produces open, pyramid-shaped panicle seed heads.
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or folded vernation; prominent boat-shaped (keeled) tips; smooth surface with a distinct mid-vein (twin veins); ligule is very short and membranous; auricles are absent; collar is narrow to medium.
Root System
Fibrous and rhizomatous; moderately deep for a cool-season grass but shallower than tall fescue; tends to form a significant thatch layer; excellent sod-forming capability and moderate establishment speed from seed.
Growing Information
Origin Region
Native to Europe, North Asia, and Morocco; naturalized and widely cultivated in North America and temperate climates globally
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod
Sunlight & Water Needs
Prefers Full Sun (6+ hours); moderate shade tolerance in specific cultivars; high water requirements during active growth; good drought dormancy (turns brown but survives) but low drought resistance compared to fescue; prefers well-drained soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; frequent mowing needed during spring/fall flushes; high fertilization needs (2-4 lbs N/1000 sq ft/year); requires periodic dethatching and aeration; High maintenance level.
Special Characteristics
High traffic/wear tolerance via rhizome recovery; susceptible to necrotic ring spot, summer patch, and powdery mildew; salt sensitivity is moderate; excellent aesthetics and 'barefoot' feel.
Ecological Information
Introduced/Naturalized in North America; provides cover for small mammals and food for various lepidoptera larvae; excellent soil stabilizer for erosion control on slopes; often blended with Perennial Ryegrass or Fine Fescue for genetic diversity and shade adaptation.