Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 physiological pathway
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely a common turf-type variety or blend; specific cultivar difficult to identify visually from image but exhibits standard darker green hue and typical density of common residential mixtures.
Hardiness Zones
USDA Hardiness Zones 2-7. Excellent cold tolerance; enters winter dormancy and survives sub-zero temperatures. Poor heat tolerance in the deep South.
About This Grass
A fine to medium-textured grass with a distinctive dark green to blue-green color. In the provided image, it shows a dense, lush growth pattern common in well-maintained lawns. It grows 12-24 inches if unmowed, producing panicle-type seed heads that are branched and pyramid-shaped.
Blade Characteristics
Blades are 2-4mm wide (medium), featuring a distinct 'boat-shaped' tip (folded at the end). Vernation is folded in the bud. The upper surface is smooth with a prominent center vein (midrib) that looks like 'twin tracks.' Ligule is short and membranous; auricles are absent.
Root System
Moderately shallow fibrous root system supported by an extensive network of rhizomes. High thatch tendency due to rhizome production; slow to moderate establishment from seed but forms a very durable sod.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; widely adapted and naturalized across North America, particularly in the northern and transition zones.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, uniform sod with high self-repair capability.
Sunlight & Water Needs
Prefers Full Sun (6+ hours) but can tolerate light shade. Requires moderate to high watering; will enter dormancy (turn brown) during extreme drought to protect the crown but recovers quickly with water. Prefers well-drained fertile soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.5 to 3.5 inches. High maintenance level; requires 2-4 lbs of Nitrogen per 1000 sq ft annually. Benefits from core aeration and periodic dethatching due to its rhizomatous growth.
Special Characteristics
Excellent traffic and wear tolerance due to rhizomes. Susceptible to leaf spot, melting out, and necrotic ring spot during humid conditions. High aesthetic value for home lawns and sports fields.
Ecological Information
Introduced and naturalized in North America. Provides soil stabilization and filtration. Often planted in a 'Northern Mix' with Perennial Ryegrass and Fine Fescues to provide genetic diversity and disease resistance.