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 Lawn-grade Kentucky Bluegrass blend (likely mixed with some Fine Fescue)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; enters winter dormancy and turns brown in extreme cold.
About This Grass
A dense, low-growing turf grass with a rich green to blue-green color. When unmowed, it reaches 6-12 inches; maintained, it forms a soft, uniform carpet. Seed heads are open, airy panicles, pyramidal in shape.
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or flat; distinctive boat-shaped (keeled) tip; dark green to blue-green color; vernation is folded in the bud; ligule is short and membranous; auricles are absent; collar is narrow.
Root System
Moderately shallow fibrous root system with extensive underground rhizomes; high thatch-forming tendency; slow establishment from seed but forms a very durable sod once mature.
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco and Algeria; widely adapted to temperate climates globally.
Growth Habit
Rhizomatous (spreading underground by rhizomes), forming a dense, thick sod; slow to moderate spread rate.
Sunlight & Water Needs
Full sun preferred (minimum 6 hours); moderate shade tolerance; requires regular watering (1 inch per week); moderate drought tolerance but will go dormant in extreme heat/drought.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches; weekly mowing; requires high nitrogen fertilization (2-4 lbs N per 1000 sq ft annually); high maintenance; requires periodic dethatching.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot and dollar spot; good salt tolerance; high aesthetic value for home lawns and sports fields.
Ecological Information
Introduced and naturalized in North America; provides cover for small mammals and birds; low wildlife forage value compared to bunchgrasses; can be aggressive in native prairie restorations.