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, dense growth, and excellent disease resistance)
Hardiness Zones
USDA Hardiness Zones 3-7, excellent cold tolerance, moderate heat tolerance, goes dormant in extreme heat and cold.
About This Grass
Forms a dense, high-quality turf with medium-fine texture. Reaches 18-24 inches if unmowed, maintained at 1.5-2.5 inches. Color ranges from medium to dark blue-green. Seed heads are pyramidal panicles appearing in late spring.
Blade Characteristics
Blades are medium-width (3-4mm), flat to folded, with distinctive boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, auricles are absent.
Root System
Moderate depth (6-12 inches) with extensive fibrous roots and strong rhizomes. Forms a very dense sod, medium thatch tendency, moderate establishment speed from seed.
Growing Information
Origin Region
Europe and northern Asia; widely cultivated across North America, especially in the northern US and Canada
Growth Habit
Rhizomatous, spreading aggressively via underground stems to form a dense, uniform sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high water needs, fair to moderate drought tolerance (enters dormancy during severe drought). Prefers well-drained loamy soils with pH 6.0-7.0.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches. Requires regular mowing, moderate to high fertilization (3-4 lbs N per 1000 sq ft annually), regular aeration and occasional dethatching. High maintenance level.
Special Characteristics
Excellent wear tolerance and self-repairing capability via rhizomes. Prone to summer patch and leaf spot if over-fertilized. Poor shade tolerance. Good erosion control due to dense root mat.
Ecological Information
Introduced species in North America. Provides low wildlife forage value compared to native prairie grasses, excellent for soil stabilization, urban heat island reduction, and water filtration.