Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or unknown residential cultivar (appearing as a typical lawn-grade mix)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters winter dormancy; struggles in the hot humid South (Zones 8-10) without heavy irrigation.
About This Grass
A medium-textured turf grass that forms a soft, dense carpet. Mown height displays a rich emerald to blue-green color; unmown height can reach 12-24 inches with panicle-type seed heads. Notable for going dormant (browning) during peak summer heat/drought.
Blade Characteristics
Narrow to medium (2-4mm) width; folded vernation; distinct 'boat-shaped' leaf tips; smooth upper surface with a prominent center vein (keel); membranous ligule; no auricles.
Root System
Fibrous and rhizomatous; relatively shallow compared to fescues (typically 6-12 inches deep); forms significant thatch; moderate establishment speed; excellent wear recovery due to spreading rhizomes.
Growing Information
Origin Region
Native to Europe, North Asia, and Northern Africa; naturalized across North America
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod
Sunlight & Water Needs
Full sun preferred (requires 6+ hours); moderate shade tolerance; requires regular watering (1 inch per week) to maintain green color during summer; prefers fertile, well-draining soil with PH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches; high maintenance level; requires 2-4 lbs Nitrogen per 1000 sq ft annually; needs periodic dethatching and core aeration.
Special Characteristics
Excellent traffic tolerance and self-healing ability; susceptible to Necrotic Ring Spot and Summer Patch; attractive color; high aesthetic value for home lawns.
Ecological Information
Introduced species in North America; provides cover for small foraging birds; helps stabilize soil via dense rhizome mats; often mixed with Fine Fescue or Perennial Ryegrass for biodiversity and shade resilience.