Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn, Turf, Sports Turf, Golf Course Grass
Variety / Cultivar
Unknown common variety; characteristics suggest the 'Midnight' or 'Elite' type lineage due to color and density
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance but struggles in the heat of the Deep South. Excellent winter hardiness with typical winter dormancy.
About This Grass
A high-quality turfgrass with a rich green to blue-green color; forms a dense, uniform carpet. It has a medium to fine texture and typically grows 1-3 feet tall if left unmowed. In lawns, it is maintained at lower heights. Seed heads are open, airy panicles shaped like a pyramid.
Blade Characteristics
Blade width is fine to medium (2-4mm). Features a distinct 'boat-shaped' tip with a central groove (keel). Leaves are folded in the bud (folded vernation). The ligule is short and membranous; auricles are absent. Color is typical deep green.
Root System
Vigorous rhizomatous system that typically concentrates in the top 6-10 inches of soil. Excellent sod-forming ability with a high thatch-forming tendency but good recovery from wear. Slow to establish from seed compared to ryegrass.
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco; widely naturalized across North America and temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, thick sod; slow to moderate spread rate
Sunlight & Water Needs
Prefers full sun (minimum 6-8 hours); poor to moderate shade tolerance. High water requirements (1-1.5 inches per week) and will go dormant (brown) during extended drought to protect the crown. Prefers well-drained soil, pH 6.0-7.0.
Mowing & Maintenance
Ideal height: 2.0-3.5 inches. High maintenance level: requires regular fertilization (3-5 lbs N per 1000 sq ft per year). Requires periodic dethatching and core aeration due to rhizome growth.
Special Characteristics
Exceptional wear tolerance and self-repairing ability due to rhizomes. Susceptible to summer patch, dollar spot, and necrotic ring spot. High aesthetic value for residential lawns and sports fields. Moderate salt tolerance.
Ecological Information
Introduced/Naturalized in North America. Provides habitat and nesting material for small birds and insects. High soil stabilization value due to dense rhizome network. Often sold in 'Sun and Shade' mixes with Fine Fescues and Perennial Ryegrass.