Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
'Midnight' or similar dark-green dense turf cultivars
Hardiness Zones
USDA Hardiness Zones 3 to 7, exhibits good cold tolerance but struggles in extreme southern heat unless irrigated.
About This Grass
Forms a dense, uniform, medium-textured turf with rich medium to dark green color. Reaches 18 to 24 inches if unmoved, but maintained at 1.5 to 3 inches. Produces characteristic pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium width (2-4mm), flat or folded with distinct boat-shaped tips and parallel veins. Vernation is folded in the bud. Ligule is short and membranous, auricles absent.
Root System
Moderately deep fibrous root system with extensive rhizomes. Tends to form moderate thatch over time. Slow to establish from seed, but creates a tough, resilient sod once mature.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via aggressive creeping rhizomes to form a dense sod
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily), moderate to high watering needs, goes dormant during severe summer droughts, prefers well-drained fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Maintain mowing height between 2.0 to 3.0 inches. Medium-high maintenance level, requiring 3-4 lbs N per 1000 sq ft annually, regular irrigation, and periodic dethatching/aeration.
Special Characteristics
Excellent wear tolerance and self-healing ability due to rhizomes. Good winter color retention in milder cool-season zones, moderate disease resistance depending on the cultivar.
Ecological Information
Introduced species in North America, provides excellent erosion control and dense ground cover, frequently blended with Perennial Ryegrass and Tall Fescue in northern turf seed mixes.