Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf
Hardiness Zones
USDA Hardiness Zones 3 to 7. Excellent cold tolerance, survives winters up to -30°F or lower. Struggles in extreme southern heat without irrigation.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Standard turf type cultivars (e.g., 'Midnight', 'Bewitched')
About This Grass
Fine to medium texture turfgrass with a rich dark green to blue-green color. Forms a very dense, attractive carpet when well-maintained. Height ranges from 1.5 to 2.5 inches when mowed, but can reach 18-24 inches if left unmowed with open, pyramidal panicle seed heads.
Blade Characteristics
Fine to medium width (2-4mm), folded in the bud (vernation), with distinctive boat-shaped tips. Parallel veins are visible with a prominent midrib. Ligule is short and membranous, auricles are absent.
Root System
Moderately deep fibrous root system combined with vigorous underground rhizomes. Forms a very tough, dense sod. Moderate establishment speed, prone to thatch buildup under high fertilization.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod with underground spreading stems
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high water needs to maintain green color during summer, good cold tolerance but enters semi-dormancy during severe summer heat and drought. Prefers well-drained, fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches. Requires medium-high maintenance including regular fertilization (3-4 lbs N per 1000 sq ft per year), periodic dethatching, core aeration, and irrigation during dry periods.
Special Characteristics
Exceptional wear tolerance and self-repairing capability due to rhizomes. Good winter color retention in milder cool-season zones. Moderate shade tolerance compared to fine fescues.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome network. Commonly blended with Perennial Ryegrass and Tall Fescue in turf seed mixes.