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
USDA Hardiness Zones 3 to 7. Excellent cold tolerance, goes dormant in extreme heat unless irrigated.
Grass Family
Poaceae, subfamily Pooideae
Variety / Cultivar
Midnight (known for dark green color and dense growth)
About This Grass
Forms a lush, dense, high-quality turf with a medium-fine texture and rich dark green to blue-green color. Reaches up to 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Features open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium-fine (2-4mm wide), flat to folded with prominent parallel veins and characteristic boat-shaped (prow-shaped) tips. Vernation is folded in the bud. Ligule is short and membranous, with no auricles.
Root System
Moderate to deep fibrous root system with extensive underground rhizomes. Can develop a moderate amount of thatch if over-fertilized. Establishes relatively slowly from seed, but creates an extremely tough, wear-recovering sod once mature.
Growing Information
Origin Region
Europe, Northern Asia, and mountain regions of North America. Widely cultivated throughout the cool, humid, and transitional regions of the United States and Canada.
Growth Habit
Aggressively rhizomatous, forming a dense sod and spreading underground via subterranean stems.
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily) for optimal growth, with limited shade tolerance. High water requirements to maintain green color during summer; enters summer dormancy under prolonged drought.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during peak spring and fall growth periods. Medium to high maintenance level, needing 3-4 lbs of nitrogen per 1000 sq ft annually, regular irrigation, and periodic dethatching.
Special Characteristics
Exceptional cold hardiness, excellent self-repairing wear tolerance due to rhizomes, good drought recovery via underground rhizomes, and fine texture. Susceptible to certain diseases like dollar spot, leaf spot, and summer patch.
Ecological Information
Introduced species in North America widely naturalized in cool temperate zones. Provides good soil stabilization and erosion control through its dense root and rhizome network. Commonly blended with Perennial Ryegrass and Fine Fescues.