Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common or 'Midnight' type (unspecified variety visible)
Hardiness Zones
USDA Zones 2-7. Excellent cold tolerance. Enters semi-dormancy during hot, dry summer periods and winter dormancy in freezing temperatures.
About This Grass
A dense, low-growing turf grass with a medium-fine texture and dark green color. When unmowed, it reaches 12-24 inches with open, pyramidal panicle seed heads. In the image, it shows a characteristic lush, uniform appearance with medium density.
Blade Characteristics
Bades are 2-4mm wide (medium-fine), V-shaped or folded, with a distinct boat-shaped tip. Color is dark to medium green. Vernation is folded in the bud; ligules are short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system complemented by extensive rhizomes. Forms a heavy thatch layer and excellent sod density. Slow to establish from seed but recovers well from wear via rhizome expansion.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Algeria and Morocco; widely adapted to temperate climates globally.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, sod-forming mat with a moderate rate of spread.
Sunlight & Water Needs
Full Sun preferred (6+ hours), moderate shade tolerance. High water requirements; requires regular irrigation to maintain green color during summer heat. Prefers well-drained, fertile soils with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.0-3.5 inches. Mowing frequency 1-2 times weekly. Fertilization: 2-4 lbs N per 1000 sq ft annually. Requires periodic dethatching and core aeration. High maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes. Good disease resistance in modern cultivars (though susceptible to Leaf Spot and Necrotic Ring Spot). High aesthetic appeal and soft texture.
Ecological Information
Introduced/Naturalized in North America. Provides soil stabilization and filtration. Valuable for preventing erosion on slopes. Often mixed with Perennial Ryegrass or Fine Fescue for improved resilience.