Kentucky Bluegrass

Reg Newman
Scientific name: 

Poa pratensis L.

Agronomic Grass
Annual precip. min (mm): 
Annual precip. max (mm): 
Seed size: 
Seeds per kg: 
Typical seeding objectives: 
PR Suitability note: 
Kentucky bluegrass is widely adapted, and can be found throughout the Peace region.
Key considerations: 
Kentucky bluegrass is long-lived and considered a minor upland invasive. Alternative species should be considered, when there is a native plant community objective. More productive and less persistent species are likely to be preferred when there is forage enhancement objective.
General Description: 

Kentucky bluegrass is a widely adapted, long-lived, persistent, low-growing perennial grass. Its roots are shallow, fibrous and concentrated near the soil surface. It eventually forms a very firm sod from the spread of slender rhizomes. Characteristics of the rhizomes vary with variety.

Kentucky bluegrass produces fine stems up to 75 cm (30 in.). The leaves are basal, soft, and smooth. At the bud stage, leaf blades are folded, flat, or V-shaped, with a boat-shaped tip. Leaf blades when flattened out are 2 to 5 mm wide.

Seed heads form on bluish-coloured triangular-shaped panicles about 5 to 10 cm (2 to 4 in.) long. There are 3 to 5 flowers on each spikelet. Seed is produced by either cross-pollination or vegetative means, and seeds are very small, about 5 mm long.

Kentucky bluegrass was introduced to North America from Europe, where it was known as “smooth meadow grass.” It became known as the “white man’s foot grass” to the First Nations, because it followed settlement as it moved west.
Habitat and climate: 
Kentucky bluegrass is widespread and adapted to a variety of soils. This grass grows well in open, montane woodlands, grasslands, moist and dry meadows, and the boreal forest. It readily competes with and often dominates native species on disturbed sites.
Used in reclamation, grazing, and turf.
Optimal time of grazing use: 
Early season grazing is best.
Recovery after use (rating): 
Recovery after use: 
Kentucky bluegrass is highly resistant to grazing. Under moist conditions, recovery and regrowth after grazing are quick. Grazing Kentucky bluegrass to a height of 5 to 15 cm (2 to 6 in.) helps maintain its forage quality.
Forage yield (rating): 
Forage yield: 
Produces 6,400 kg/ha (5,750 lb/acre) (Breton, Gray soils) or 6,000 kg/ha (5,300 lb/acre) (Lacombe, Black soils). Poor productivity when moisture limiting.
Palatability/Nutritional Value: 
In the vegetative stage, Kentucky bluegrass has 12% protein and a digestibility (Total Digestible Nutrient) composition of 67%. Quality declines significantly as this grass matures.
Longevity (rating): 
Persistence (rating): 
Kentucky bluegrass can be especially persistent in older pastures, moister regions, meadows, and swales on native range.Seed banks can persist in soil for up to four years.
Invasiveness (rating): 
It is considered a minor upland invasive in E-Flora BC’s Invasive, Noxious and Problem Plants of British Columbia 2012 Update. Its competitiveness means that it can invade pastures and native range, especially when closely grazed. It can persist in the lower part of the plant community and increases as taller species decrease.
Competitiveness (rating): 
Erosion control (rating): 
Erosion control: 
Eventually forms a dense root system that is excellent for long-term erosion control.
Drought tolerance (rating): 
Drought tolerance: 
Goes dormant during periods of drought.
Winter hardiness (rating): 
Soil texture preference (rating): 
Soil texture preference: 
Prefers well-drained, fertile, moist soils. Because of its need for moisture, Kentucky bluegrass often grows better on clay, silty, or peat soils.
Flooding tolerance (rating): 
Flooding tolerance: 
Can withstand 1 to 2 weeks flooding in the spring, several days of flooding during the growing season, and tolerates excessive root zone moisture.
Salinity tolerance (rating): 
Acidity tolerance (rating): 
Acidity tolerance : 
Tolerates pH as low as 5.0, but prefers pH of 5.5 to 7.5
Shade tolerance: 
Medium shade tolerance
Fire tolerance (rating): 
Pests and/or disease threats: 
Silvertop can be a problem, especially with some varieties. Other disease concerns include powdery mildew, leaf rust, and ergot.
Ease of establishment (rating): 
Ease of establishment: 
Seeds germinate easily but may emerge slower than other grasses, especially where there is competition for moisture.
Suggested mixtures: 
Compatible with legumes such as birdsfoot trefoil, alsike clover, and especially compatible with white clover.
Management considerations: 
Kentucky bluegrass has a high demand for moisture, nitrogen, and phosphorus.