Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
Midnight (known for dark blue-green color and dense, compact growth)
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7, excellent cold tolerance, moderate heat tolerance, often combined with tall fescue in the transition zone.
About This Grass
Forms a dense, high-quality, fine to medium-textured turf with an attractive medium to dark green or blue-green color. Mowed height is typically maintained at 1.5 to 2.5 inches, while unmowed growth can reach 18 to 24 inches with distinctive pyramidal panicle seed heads.
Blade Characteristics
Blades are medium width (2-4mm), flat with distinct parallel veins and a prominent midrib, featuring characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, and auricles are absent.
Root System
Moderately deep fibrous root system combined with aggressive rhizomes, creating a dense sod. Moderate to high thatch-forming tendency, slow to moderate establishment speed from seed.
Growing Information
Origin Region
Europe, Northern Asia, and parts of North Africa; widely cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading via underground stems to form a dense, uniform turf sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high water needs, fair drought tolerance (goes dormant in severe drought), prefers well-drained fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Medium to high maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft annually), frequent mowing, and periodic dethatching and aeration.
Special Characteristics
Excellent traffic and wear tolerance due to self-repairing rhizomes, good cold and winter hardiness, moderate disease susceptibility (e.g., dollar spot, leaf spot), poor shade tolerance compared to fine fescues.
Ecological Information
Introduced species in North America, provides standard lawn cover and minor wildlife value, excellent for erosion control on slopes, commonly blended with perennial ryegrass and fescues.