Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Hardiness Zones
Thrives in USDA Hardiness Zones 3-7. Excellent cold tolerance, surviving freezing winters under dormancy. Struggles in extreme summer heat unless irrigated, making it less ideal for deep southern climates.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Midnight (known for dark blue-green color, dense growth, and good disease resistance)
About This Grass
Forms a dense, high-quality turf with a fine to medium texture. Unmowed height can reach 18-24 inches with pyramidal seed heads, but maintained turf is kept low at 1.5-2.5 inches. Color ranges from medium to dark blue-green, with excellent winter color retention in milder cool regions.
Blade Characteristics
Blades are medium-narrow (2-4mm), flat to folded with prominent parallel veins and 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
Moderate depth (6-18 inches) fibrous root system combined with extensive underground rhizomes. Forms a very dense sod with moderate thatch-forming tendencies. Slow to moderate establishment speed from seed.
Growing Information
Origin Region
Europe, Northern Asia, and parts of the mountains of North America; widely cultivated across cool temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via aggressive horizontal shoots to form a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours of direct sunlight) for optimal performance, with poor shade tolerance. Moderate to high water needs; goes into summer dormancy under severe drought conditions but recovers well. Prefers well-drained, fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires regular mowing frequency during peak spring and fall growth. High maintenance level: needs 2-4 lbs N per 1000 sq ft annually, regular irrigation, and occasional aeration and dethatching.
Special Characteristics
Good wear tolerance and excellent self-repairing capabilities due to rhizomes. Susceptible to certain diseases like leaf spot, dollar spot, and summer patch. Good drought recovery via underground rhizomes, but poor salt and heavy shade tolerance.
Ecological Information
Introduced species in North America widely naturalized in cool temperate zones. Provides low wildlife forage value compared to native prairies, but excellent for soil stabilization, erosion control, and urban cooling. Frequently blended with Perennial Ryegrass and Fine Fescues.