Kentucky Bluegrass (found within a lawn infested with Heal-all)
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or unknown lawn cultivar (visible alongside Prunella vulgaris weed)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance, poor heat tolerance in the deep South.
About This Grass
A fine to medium textured turfgrass with a distinct dark green to blue-green color. It forms a dense, lush carpet when healthy, though here it is being outcompeted by broadleaf weeds. Seed heads are open panicles.
Blade Characteristics
Bowers-shaped (boat-shaped) tips are the diagnostic feature. Blades are 2-4mm wide, smooth on both sides, with a folded vernation. Ligule is very short and membranous; auricles are absent.
Root System
Moderately deep but primarily consists of a dense network of underground rhizomes. High thatch tendency and excellent sod-forming ability with good recovery from wear.
Growing Information
Origin Region
Europe and Northern Asia; widely adapted to temperate climates globally
Growth Habit
Rhizomatous (spreading underground) and mat-forming, creating a dense sod
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) but tolerates partial shade. Requires moderate to high water; enters dormancy during severe drought.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches. High maintenance requirements including regular fertilization (2-4 lbs N/1000 sq ft) and periodic dethatching.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot and dollar spot; currently under pressure from invasive 'Heal-all' (Prunella vulgaris).
Ecological Information
Introduced and naturalized in North America. Provides soil stabilization but can be outcompeted by aggressive creepers like the visible Prunella in low-mowed or wet conditions.