Poa pratensis, commonly known as Kentucky bluegrass (or blue grass), smooth meadow-grass, or common meadow-grass, is a perennial species of grass native to practically all of Europe, North Asia and the mountains of Algeria and Morocco. Although the species is spread over all of the cool, humid parts of the United States, it is not native to North America. The Spanish Empire brought the seeds of Kentucky bluegrass to the New World in mixtures with other grasses. In its native range, Poa pratensis forms a valuable pasture plant, characteristic of well-drained, fertile soil. It is also used for making lawns in parks and gardens and has established itself as a common invasive weed across cool moist climates like the Pacific Northwest, and Northeastern United States. When found on native grasslands in Canada, for example, it is considered an unwelcome exotic plant, and is indicative of a disturbed and degraded landscape.
Poa pratensis was one of the many species described by Carl Linnaeus in his landmark work Species Plantarum in 1753. Poa is Greek for fodder and pratensis is derived from pratum, the Latin for meadow. The name Kentucky bluegrass derives from its flower heads, which are blue when the plant is allowed to grow to its natural height of 60 to 90 cm (2 to 3 feet).
There are two ill-defined subspecies:
- Poa pratensis subsp. pratensis – temperate regions
- Poa pratensis subsp. colpodea – Arctic
Poa pratensis is a herbaceous perennial plant 30–70 centimetres (12–28 in) tall. The leaves have boat-shaped tips, narrowly linear, up to 20 centimetres (8 in) long and 3–5 millimetres (0.12–0.20 in) broad, smooth or slightly roughened, with a rounded to truncate ligule 1–2 millimetres (0.039–0.079 in) long. The conical panicle is 5–20 centimetres (2–8 in) long, with 3 to 5 branches in the basal whorls; the oval spikelets are 3–6 millimetres (0.12–0.24 in) long with 2 to 5 florets, and are purplish-green or grey. They are in flower from May to July, compared to annual meadowgrass (Poa annua) which is in flower for eight months of the year. Poa pratensis has a fairly prominent mid-vein (center of the blade).
The ligule is extremely short and square-ended, making a contrast with annual meadowgrass (Poa annua) and rough meadowgrass (Poa trivialis) in which it is silvery and pointed. The Kentucky bluegrass is a dark green/blue compared to the apple-green color of Poa annua and Poa trivialis.
This species is among the food plants of the caterpillars of the meadow brown (Maniola jurtina), gatekeeper (Pyronia tithonus), and pepper-and-salt skipper butterflies; the common sun beetle (Amara aenea) (adults feed on the developing seeds), Eupelix cuspidata of the leafhopper family, and Myrmus miriformis, a grassbug (feeds on young blades and developing seeds).
Cultivation and production
NFL Playing Surfaces
- Lambeau Field in Green Bay, WI
- FirstEnergy Stadium in Cleveland, Ohio
- Empower Field at Mile High in Denver, Colorado
- Heinz Field in Pittsburgh, Pennsylvania
- Soldier Field in Chicago, Illinois
MLB Playing Surfaces
- Oriole Park at Camden Yards in Baltimore, MD
- Fenway Park in Boston, MA
- American Family Field in Milwaukee, WI
- Yankee Stadium in Bronx, NY
- Citi Field in Queens, NY
- Busch Stadium in St.Louis, MO
- Nationals Park in Washington, DC
- PNC Park in Pittsburgh, PA
- Wrigley Field in Chicago, IL
- Guaranteed Rate Field in Chicago, IL
- Citizens Bank Park in Philadelphia, PA
- Comerica Park in Detroit, MI
- Progressive Field in Cleveland, OH
- Target Field in Minneapolis, MN
- Kauffman Stadium in Kansas City, MO (Kentucky Bluegrass/Perennial Ryegrass Blend)
- Coors Field in Denver, CO (Kentucky Bluegrass/Perennial Ryegrass Blend)
- T-Mobile Park in Seattle, WA (Kentucky Bluegrass/Perennial Ryegrass Blend)
- Martin Anderson, Texas AgriLife Extension Service. "Kentucky Bluegrass". Aggie Horticulture.
Ksenija Vujnovic; Ross W. Wein (September 1997). "An Inventory of Remnant Prairie Grasslands Within the Central Parkland Natural Sub-Region of Alberta" (PDF): 5. Cite journal requires
- Dag Ryen (letter to the editor) (June 3, 1993). "What Makes Kentucky's Bluegrass Blue". The New York Times. p. 22. Retrieved 2018-06-15.
- Natural England description on website Archived 2009-02-23 at the Wayback Machine
Wikimedia Commons has media related to:
poa pratensis (category)
- Flora Europaea: Poa pratensis
- European Poa Database
- Horticultural information on this turfgrass; growing it in the home garden * The Observers Book of Grasses, Sedges and Rushes. Frances Rose. pages 42–43
- PennState Extension Kentucky Bluegrass Facts and Identification
- Kew gardens grass database