Kentucky Bluegrass
Poa pratensis · Cool-season, perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass, Erosion Control
Variety / Cultivar
Standard or common turf-type varieties, often blended with other cool-season grasses like Perennial Ryegrass
Hardiness Zones
USDA Hardiness Zones 3 through 7 (can survive in Zone 8 with proper irrigation). Excellent cold tolerance, surviving extreme winter temperatures through dormancy. Performs poorly in extreme summer heat unless irrigated.
About This Grass
Forms a dense, high-quality turf with a medium-fine texture. Reaches heights of 18-24 inches if left unmowed, but maintained at 2-3 inches. Color ranges from medium to dark green, often with a slight blue-green tint. Shows winter dormancy in colder climates.
Blade Characteristics
Medium-fine width (2-4mm), flat to V-shaped blades with distinctive boat-shaped tips. Vernation is folded in the bud. Leaves feature prominent parallel veins and a distinctive pair of clear, smooth parallel lines (tramlines) on either side of the midrib. Ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system combined with an extensive rhizome network. Tends to form a moderate amount of thatch under high fertility and watering. Moderate to slow establishment speed from seed, but forms a dense, tough sod once mature.
Growing Information
Origin Region
Native to Europe, northern Asia, and parts of the northern US/Canada. Widely cultivated throughout the cool-humid and cool-arid regions of North America, Europe, and northern Asia.
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod and spreading through underground stems to repair damaged areas.
Sunlight & Water Needs
Requires full sun for optimal growth (at least 6 hours of direct sunlight), with limited shade tolerance. Requires moderate to high moisture levels, needing about 1 inch of water per week. Good winter hardiness but enters dormancy during severe summer droughts.
Mowing & Maintenance
Ideal mowing height ranges from 2.0 to 3.5 inches. Requires regular mowing during active spring and fall growth periods. High fertilization needs (2-4 lbs N per 1000 sq ft per year). Regular dethatching and core aeration are recommended. Maintenance level is high.
Special Characteristics
High traffic and wear tolerance due to aggressive rhizome recovery. Good resistance to most common turf diseases, though susceptible to necrotic ring spot and leaf spot under stress. Excellent sod strength and erosion control capabilities.
Ecological Information
Introduced species in North America. Provides moderate wildlife value for ground-nesting birds and small mammals. Excellent for soil stabilization, dust reduction, and carbon sequestration. Frequently used in seed blends with Perennial Ryegrass and Fine Fescue.