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 standard lawn cultivars like 'Midnight' or 'Baron', known for deep green color and density
Hardiness Zones
USDA Hardiness Zones 3-7, excellent cold tolerance, moderate heat tolerance, goes dormant or semi-dormant in extreme summer heat.
About This Grass
Forms a dense, uniform, medium-textured turf with a rich dark green to blue-green color. Mowed height is typically 2 to 3 inches, while unmowed growth can reach 18 to 24 inches with pyramidal panicle seed heads.
Blade Characteristics
Medium width (3-4mm), folded vernation in the bud, distinct boat-shaped tips, prominent parallel veins with a tramline effect, smooth texture, short membranous ligule, and absent auricles.
Root System
Moderately deep fibrous root system with aggressive rhizomes, forms a dense sod, moderate establishment speed from seed, and excellent wear recovery.
Growing Information
Origin Region
Europe and Northern Asia, widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense turf mat via underground creeping stems
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours), moderate to high watering needs, moderate drought tolerance entering dormancy during severe dry spells, prefers well-drained fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches, frequent mowing during peak spring growth, fertilization needs of 2-4 lbs N per 1000 sq ft annually, moderate to high maintenance level requiring occasional dethatching and aeration.
Special Characteristics
High wear tolerance and self-repairing via rhizomes, moderate disease susceptibility (summer patch, dollar spot), poor shade tolerance, excellent cold-season color retention.
Ecological Information
Introduced species in North America, provides good soil stabilization and erosion control, frequently blended with Perennial Ryegrass and Fine Fescues for home lawns and sports fields.