Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Standard commercial blend (e.g., 'Midnight', 'Baronie')
Hardiness Zones
USDA Hardiness Zones 3-8. Excellent cold tolerance, goes into winter dormancy in northern zones, moderate summer heat stress in the deep south.
About This Grass
Forms a dense, fine to medium-textured turf with an upright growth habit. Bright to dark green color with good wear resistance. Unmowed height can reach 18-24 inches, maintained at 1.5-2.5 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium-narrow (2-4mm), flat or folded, with characteristic boat-shaped tips. Vernation is folded in the bud. Color ranges from medium to dark green. Ligule is short and membranous; auricles are absent; collar is narrow and distinct.
Root System
Moderately deep fibrous root system combined with strong spreading rhizomes. Forms a dense sod layer. Tends to build up thatch if over-fertilized. Slow to medium establishment speed from seed.
Growing Information
Origin Region
Europe, northern Asia, and parts of the mountains in North America; widely cultivated in temperate regions worldwide.
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf sod.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high water needs for optimal appearance, moderate drought tolerance (goes dormant in severe drought), prefers well-drained loamy soils with pH 6.0-7.0.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches. Requires frequent mowing during peak growth spring/fall. Medium-high maintenance level, needs 2-4 lbs N per 1000 sq ft annually, regular aeration, and occasional dethatching.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomes, good cold hardiness, moderate disease susceptibility (dollar spot, leaf spot, summer patch), excellent winter color retention in milder cool climates, rapid recovery from damage.
Ecological Information
Widely naturalized in North America. Provides good soil stabilization and erosion control, forms thick root mats for water filtration, commonly blended with Perennial Ryegrass and Fine Fescue.