Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
Common or mixed turf cultivars (e.g., 'Midnight', 'Baron')
Hardiness Zones
USDA Hardiness Zones 3-7, excellent cold tolerance down to extreme sub-zero temperatures, goes semi-dormant during intense summer heat.
About This Grass
Dense, fine-to-medium-textured turf with a rich dark green to blue-green color. Forms a tight, durable carpet. Mower-maintained height typically 2-3 inches, while unmowed seed heads can reach 18-24 inches with an open panicle structure.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded with distinct parallel veins, classic boat-shaped tips, folded in the bud (vernation), smooth texture with prominent midvein, short membranous ligule, and no auricles.
Root System
Moderately deep fibrous root system combined with vigorous rhizomes. Forms a dense, tough sod. Tends to build up moderate thatch if over-fertilized. Medium establishment speed from seed.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for best performance, moderate to high water needs, good cold-season drought dormancy tolerance, prefers well-drained fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height 2.0 to 3.0 inches. Requires regular mowing, medium-high fertilization (3-4 lbs N per 1000 sq ft annually), periodic aeration and dethatching, and high maintenance level overall.
Special Characteristics
High traffic and wear tolerance due to aggressive rhizomatous recovery, moderate disease susceptibility (leaf spot, dollar spot, summer patch), poor shade tolerance compared to fescues, excellent erosion control.
Ecological Information
Introduced species in North America, widely utilized for residential and commercial lawns, provides good soil stabilization, moderate wildlife food and cover value, commonly blended with Perennial Ryegrass and Fine Fescues.