Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf, Golf Course Rough, Sports Turf
Variety / Cultivar
Common/Mixed Cultivar (e.g., 'Midnight' or 'Baron' types)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance (goes dormant in summer in Transition Zones).
About This Grass
Medium-textured turf grass with a distinct dark green to blue-green color. Forms a dense, uniform carpet. Seed heads are open, airy panicles (pyramidal shape) when unmowed.
Blade Characteristics
Fine to medium width (2-4mm), V-shaped or flat, distinguished by a 'boat-shaped' tip. Vernation is folded; ligule is short and membranous; auricles are absent.
Root System
Spreading fibrous root system with extensive rhizomes. Moderate depth (8-12 inches). High thatch tendency due to rhizome density; moderate establishment speed.
Growing Information
Origin Region
Europe, North Asia, and North Africa; naturalized throughout North America
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod
Sunlight & Water Needs
Full sun preferred (6-8 hours); moderate to high water needs; enters dormancy during severe drought; prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
1.5 to 3.5 inches height; frequent mowing; 2-4 lbs Nitrogen per 1000 sq ft annually; requires periodic core aeration; High maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; good disease resistance in modern cultivars; poor shade tolerance; high aesthetic quality.
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization and erosion control; low wildlife food value but provides cover for small insects/animals.