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 growth)
Hardiness Zones
USDA Hardiness Zones 3 to 7, excellent cold tolerance, goes semi-dormant in extreme summer heat.
About This Grass
Forms a dense, high-quality turf with a rich blue-green color. Matures to 18-24 inches if unmowed, but maintained at 2-3 inches. Features open, pyramidal panicle seed heads.
Blade Characteristics
Medium-fine width (2-3mm), flat to folded shape with distinctive boat-shaped tips and prominent parallel veins giving a railroad-track appearance. Vernation is folded in the bud. Ligule is short and membranous.
Root System
Moderately deep fibrous root system with extensive underground rhizomes. Establishes slowly from seed, but forms a very dense sod with moderate thatch-forming tendencies.
Growing Information
Origin Region
Europe and Northern Asia; widely cultivated across North America, especially northern and transition zones
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily), moderate to high water needs, fair drought tolerance (goes dormant during severe drought), prefers well-drained fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Mow at 2.0 to 3.5 inches. Medium-high maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft annually) and periodic aeration and dethatching.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomatous recovery, good cold hardiness, moderate shade tolerance compared to fine fescues, excellent self-repair capabilities.
Ecological Information
Introduced species in North America, provides standard lawn cover and minor wildlife value, excellent for soil stabilization and preventing erosion.