Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Hardiness Zones
Thrives in USDA Hardiness Zones 3 to 7, exhibits excellent cold tolerance, but can struggle in intense summer heat without irrigation. Common in the northern U.S. and transition zones.
Grass Family
Poaceae, subfamily Pooideae
Variety / Cultivar
Common blend (such as 'Midnight' or 'Baron'), known for dark green color and dense turf formation.
About This Grass
Forms a dense, fine to medium-textured turf with an attractive blue-green to dark green color. Typically maintained at heights of 1.5 to 2.5 inches, but can reach 18 to 24 inches if unmowed, producing open, pyramidal panicle seed heads.
Blade Characteristics
Blades are medium width (2-4mm), flat to folded with distinct parallel veins, and feature characteristic boat-shaped tips. Vernation is folded in the bud. Ligules are short and membranous, and auricles are absent.
Root System
Moderate to deep fibrous root system combined with aggressive rhizomes, creating a dense sod. Tends to build up thatch moderately and has a slow to moderate establishment speed from seed.
Growing Information
Origin Region
Native to Europe and northern Asia, widely naturalized and cultivated across North America and temperate regions worldwide.
Growth Habit
Rhizomatous, forming a dense, uniform sod with underground stems that spread to repair damaged areas.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) with moderate to high water needs. Good cold-induced dormancy for drought survival, but fair to moderate active drought tolerance. Prefers well-drained, fertile 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 growth, moderate to high fertilization (3-5 lbs N per 1000 sq ft annually), regular aeration, and occasional dethatching. Maintenance level is high.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomatous recovery, good winter color retention in milder climates, moderate disease susceptibility (e.g., dollar spot, leaf spot), and poor dense shade tolerance.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control, filters runoff water effectively, and is commonly blended with Perennial Ryegrass and Fine Fescues in northern lawn seed mixtures.