Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Commercial Elite (exact cultivar indistinguishable from image)
Hardiness Zones
USDA Zones 3-7; excellent cold tolerance, poor heat tolerance compared to warm-season grasses. Goes dormant in winter and extreme summer heat.
About This Grass
A medium-textured turf grass known for its dark green to blue-green color. It forms a lush, carpet-like lawn. Unmowed, it reaches 12-24 inches; mowed, it provides a very dense surface. Seed heads are open, airy panicles.
Blade Characteristics
Boat-shaped tips (distinguishing feature), blades are medium width (2-4mm), V-shaped or flat, folded in the bud (folded vernation). Blades are smooth with a prominent center vein (keel); ligule is short and membranous; auricles are absent.
Root System
Relatively shallow to moderate (mostly top 6-8 inches), highly rhizomatous. Forms significant thatch. Slower to establish from seed but creates a very stable sod once mature.
Growing Information
Origin Region
Europe, Northern Asia, and North Africa; now common throughout North America
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod
Sunlight & Water Needs
Full Sun preferred (6+ hours), moderate shade tolerance. High water needs; enters dormancy during severe drought to survive. Prefers well-drained fertile soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.5–3.5 inches. Requires frequent mowing during spring/fall peaks. 2-4 lbs N per 1000 sq ft per year. High maintenance; needs periodic dethatching and aeration.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes. Susceptible to necrotic ring spot and summer patch. Low salt tolerance. Highly prized for visual appeal in residential yards and golf fairways.
Ecological Information
Introduced/Naturalized in North America. Provides habitat for small insects and soil stabilization. Often mixed with Perennial Ryegrass or Fine Fescue for better shade and disease resilience.