Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Likely an improved turf-type cultivar such as 'Midnight' or 'Mazama' based on the dark coloration and high density.
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance but prone to heat stress in the southern transition zone without irrigation.
About This Grass
A lush, high-density turf grass with a distinct dark green to blue-green color. It maintains a medium-fine texture and forms a uniform mat. Unmowed, it produces panicle-type seed heads resembling small pyramids.
Blade Characteristics
Blades are 2-4mm wide (medium-fine) with a unique boat-shaped tip. They have a prominent central vein (keel) and exhibit folded vernation. The ligule is short and membranous, and auricles are absent. Color is a rich, deep green.
Root System
Moderately deep fibrous root system with extensive horizontal rhizomes. It has a significant thatch-forming tendency but offers excellent sod strength and recovery from wear.
Growing Information
Origin Region
Native to Europe, North Asia, and Northern Africa; widely adapted to temperate climates globally, performing best in the Northern US and Canada.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod.
Sunlight & Water Needs
Prefers full sun (minimum 6-8 hours); moderate to high watering needs; enters dormancy during severe drought to survive; thrives in well-drained, slightly acidic to neutral soil (pH 6.0-7.0).
Mowing & Maintenance
Recommended mowing height is 2.0 to 3.5 inches. Requires frequent mowing and high fertilization (3-5 lbs N per 1000 sq ft per year). Benefits from regular core aeration and dethatching; high maintenance level.
Special Characteristics
Excellent traffic tolerance and recovery due to rhizome growth. Susceptible to leaf spot, summer patch, and powdery mildew in shade. Known for its 'winter brown' dormancy while remaining hardy through deep freezes.
Ecological Information
Introduced and naturalized in North America. Provides soil stabilization and erosion control. Often used in mixes with Perennial Ryegrass and Fine Fescues to improve genetic diversity and disease resistance.