Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass
Hardiness Zones
USDA Hardiness Zones 3 to 7, exhibits excellent cold tolerance but struggles with extreme summer heat unless irrigated, making it less ideal for the deep southern transition zone.
Grass Family
Poaceae, subfamily Pooideae
Variety / Cultivar
Common blend varieties such as 'Midnight' or 'Baron'
About This Grass
Forms a dense, high-quality turf with medium-fine texture and a rich dark green to blue-green color. Mown height typically ranges from 1.5 to 2.5 inches, while unmown plants can reach 18 to 24 inches with pyramidal panicle seed heads.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded shape with distinctive boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, auricles are absent, and the collar is broad and continuous.
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes. Tends to build up thatch over time if unmanaged. Establishes slowly from seed.
Growing Information
Origin Region
Europe and Northern Asia, widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, aggressively spreading via underground stems, forming a very dense, uniform sod
Sunlight & Water Needs
Requires full sun (minimum 6 hours of direct sunlight) for best performance, though some cultivars offer moderate shade tolerance. High water needs during dry spells to maintain green color; enters summer dormancy under severe drought.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires regular mowing, moderate to high fertilization (3-5 lbs N per 1000 sq ft per year), periodic dethatching, and aeration. High maintenance level.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomatous recovery. Good winter color retention in milder cool-season climates. Moderate salt and shade tolerance.
Ecological Information
Introduced species in North America. Provides good turf coverage for soil stabilization and erosion control. Frequently blended with Perennial Ryegrass and Fine Fescues to improve disease resistance and establishment speed.