Kentucky Bluegrass (Inhabited by Oregano/Marjoram weed)
Poa pratensis (Grass) and Origanum vulgare (Weed) · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass; the visible broadleaf is an Invasive/Weed Grass in this context
Variety / Cultivar
Common or 'Midnight' type Kentucky Bluegrass; the broadleaf is likely a wild Origanum species
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters semi-dormancy during hot, dry summers.
About This Grass
Medium to dark green turf with a fine to medium texture. When allowed to grow, it reaches 12-24 inches with open panicle seed heads. Note: The image shows a heavy infestation of a low-growing broadleaf weed with rounded, opposite leaves.
Blade Characteristics
Blades are 2-4mm wide, V-shaped or flat, with a distinct boat-shaped tip. Vernation is folded in the bud; ligules are short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system with extensive rhizomes. Development of rhizomes allows for excellent sod formation and recovery. Moderate thatch tendency.
Growing Information
Origin Region
Europe, Northern Asia, and Northern Africa; widely naturalized across North America
Growth Habit
Rhizomatous (underground spreading) forming a dense sod; Broadleaf weed is stoloniferous/creeping
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance. High water needs, requiring 1-1.5 inches per week. Prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; frequent mowing required during peak spring/fall growth. Fertilization: 2-4 lbs N per 1000 sq ft annually. High maintenance level.
Special Characteristics
Excellent traffic tolerance and recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; low salt tolerance; high aesthetic value.
Ecological Information
Introduced to North America; provides forage for various insects and small mammals; common in seed mixes with Tall Fescue or Perennial Ryegrass to increase sod density.