Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common blend or standard turf-type cultivars like 'Midnight' or 'Baron'
Hardiness Zones
USDA Hardiness Zones 3 through 7, occasionally 8 in northern or elevated microclimates. Excellent cold tolerance, entering semi-dormancy during severe heat or drought.
About This Grass
Forms a lush, medium-fine textured turf with a rich green to blue-green color. Mown height typically ranges from 1.5 to 2.5 inches, while unmowed growth can reach 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Blades are medium in width (2-4mm), V-shaped or flat with distinct parallel veins, featuring characteristic boat-shaped tips. Vernation is folded in the bud with a short, membranous ligule and absent auricles.
Root System
Moderately deep fibrous root system combined with aggressive rhizomes, creating a dense, tough sod. Slow to establish from seed, but has good recovery capabilities through lateral spreading.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, forming a dense, uniform sod through spreading underground stems
Sunlight & Water Needs
Requires full sun (minimum 6 hours daily) for optimal growth, though some cultivars offer moderate shade tolerance. High watering needs during dry spells to prevent summer dormancy; prefers well-drained loamy soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires medium-high maintenance including regular fertilization (3-4 lbs N per 1000 sq ft annually), frequent mowing, and periodic dethatching and aeration.
Special Characteristics
Excellent traffic and wear tolerance due to its self-repairing rhizomatous nature. Moderate drought tolerance (goes dormant in severe dry periods), fair disease susceptibility (prone to dollar spot, rust, and leaf spot), and good weed suppression when thick.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome matrix. Frequently mixed with Perennial Ryegrass and Fine Fescue in cool-season lawn seed blends.