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 lawn variety (unspecified cultivar, possibly Midnight or Baron type based on color)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters winter dormancy; struggles in the high heat of the deep South.
About This Grass
Dense, carpet-like grass with a dark green to blue-green color. It maintains a medium-fine texture and grows 12-24 inches if unmowed. It produces panicle-type seed heads that are pyramid-shaped when mature.
Blade Characteristics
Blade width is medium (2-4mm), featuring a unique boat-shaped tip. Leaf blades are V-shaped or flat, folded in the bud (vernation). Color is dark green to blue-green with a prominent midrib; ligule is short and membranous, auricles are absent.
Root System
Moderately deep fibrous root system with extensive rhizomes. Forms heavy thatch; slow to establish from seed but creates a very durable, self-repairing sod.
Growing Information
Origin Region
Native to Europe, Northern Asia, and North Africa; naturalized throughout North America in temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, thick sod
Sunlight & Water Needs
Prefers full sun (minimum 6-8 hours); moderate to high water needs; can go semi-dormant during summer drought; prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; weekly mowing; requires 2-4 lbs N per 1,000 sq ft annually; high maintenance due to fertilization and irrigation needs.
Special Characteristics
High wear tolerance and excellent recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; moderate salt tolerance.
Ecological Information
Introduced status in North America; provides cover for small mammals and birds; excellent for soil stabilization and erosion control; often blended with Perennial Ryegrass or Fine Fescue.