Kentucky bluegrass (Poa pratensis)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON NAMES:

Kentucky bluegrass

smooth meadow-grass

common meadow-grass

SCIENTIFIC SYNONYMS: There are no scientific synonyms for

Poa pratensis.

 

TAXONOMY: The currently accepted scientific name for Kentucky

bluegrass is Poa pratensis L.

 

Four subspecies have been recognized: 1) Poa pratensis ssp. agassi-

zensis (Boivin & D. Love) Taylor & McBryde; 2) Poa pratensis ssp.

alpigena (Fries) Hiitonen; 3) Poa pratensis ssp. angustifolia (L.)

Gaudin; 4) Poa pratensis ssp. pratensis.

 

Poa pratensis naturally hybridizes with several other species within
the genus, including Poa secunda, Poa arctica, Poa alpina, Poa ner-

vosa, Poa reflexa, and Poa palustris.

 

NATIVE STATUS: Native and introduced, United States and Canada.

Kentucky bluegrass is generally considered to be nonnative to North
America.  Some botanists argue, however, that populations in remote
mountain meadows of the West may be native.

 

GENERAL BOTANICAL CHARACTERISTICS: Kentucky bluegrass,

is a perennial, cool-season, sod-forming grass native to Europe. Seedhead

stems are 18 to 24 inches tall, but can be 4 to 6 inches in height when used

for intensive grazing. The seedhead has an open shape like a pyramid and produces many small seeds. There are approximately 2,177,000 seeds per

pound. Leaves are 6 to 12 inches long and boat-shaped (keeled) at the tips.

Leaves are smooth, soft, and about 1/8 to 1/4 inch wide. The plant becomes

dormant during the heat of summer, but regains or maintains its green color

in fall. Growth starts early in the spring. Tiller buds develop into stems or rhizomes. New rhizomes also arise from nodes of older rhizomes. Most

rhizomes penetrate 2 to 4 inches into the soil, but some will go down more

than 5 inches.

 

REGENERATION PROCESSES: Kentucky bluegrass propogates

itself by reseeding and vegetative spread (rhizomes).

 

HABITAT TYPES:   It has, however, become naturalized across North
America and often occurs as a herbaceous layer dominant.  In the West,
Kentucky bluegrass frequently occurs as an understory dominant in aspen
(Populus tremuloides), ponderosa pine (Pinus ponderosa), sagebrush
(Artemisia spp.)/bunchgrass (Pseudoroegneria spicata, Festuca altaica,
F. idahoensis), bunchgrass, and riparian habitats.  It is also a common
dominant of midwestern prairies.

 

Grazing-induced seral stages in which Kentucky bluegrass is the herba-

ceous layer dominant are widespread and common within ponderosa pine/

bunchgrass, sagebrush/bunchgrass, and bunchgrass habitat types Kentucky

bluegrass grows in meadows, fields, roadsides, open woods, and stream-

sides. It can grow in dry or moist soil. It is very competitive and will often

crowd out other plants.
 

 

SITE CHARACTERISTICS: Kentucky bluegrass is used throughout

the U.S. It is best adapted to well-drained, fertile, medium-textured soils

of limestone origin. It performs satisfactorily on poorly drained and heavy-textured soils. Favorable pH level for this grass is 6.0 to 7.5. Kentucky

bluegrass grows best in the humid areas. Optimum temperatures for for-

age production are between 60 F and 90°F. Although the grass is essent-

ially dormant during dry or excessively hot weather, it survives severe

droughts. It prefers sunlight but will do well in light shade with ample

moisture and nutrients.

 

SEASONAL DEVELOPMENT: Kentucky bluegrass is one of the first

grasses to resume growth in late winter or early spring. It grows rapidly,

and in many states it flowers in May. Most flowering occurrs in late May

and early June (some flowering can continue into August).  By midsummer

plants become nearly dormant. With cool temperatures and precipitation,

growth resumes in the fall and continues until daytime temperatures

approach freezing.
 

GENERAL DISTRIBUTION: Kentucky bluegrass is now found in all

states and provinces of the United States and Canada. It is adapted for

growth in cool, humid climates, and is most prevalent in the northern half

of the United States and the southern half of Canada.  It is not common in

the Gulf States nor in desert regions of the Southwest.

 

SKY MEADOWS DISTRIBUTION: To be determined.

 

IMPORTANCE AND USES: This plant is highly palatable to elk and is

one of the better grasses for deer. The tender plants are grazed immediate-

ly after growth begins and the leaves remain succulent and green as long

as soil moisture is present. Seeds are eaten by several kinds of songbirds

and rodents. Leaves are eaten by rabbits and turkey.

 

This plant provides a dense green sod especially adapted for parks and

home lawns. It can, however, become weedy or invasive in some regions

or habitats and may displace desirable vegetation if not properly managed.

 

Kentucky bluegrass is an excellent erosion control plant because of its

dense, vigorous turf forming habit. It can be used as a mix with legumes

or other grasses for erosion control in conservation cover, waterways, field borders, heavy use areas and critical areas such as steep banks and pond

edges. It is also used alone or in seed mixtures as permanent cover for tree plantings and orchards.

 

The species is highly palatable to horses, cattle, and sheep. It produces re-

latively low yields compared to other pasture grasses, but can be very pro-

ductive in the Northeast on closely grazed intensive rotational grazing

systems.

 

Kentucky bluegrass turf is excellent for ball fields and other heavy use

areas such as camp grounds, golf fairways, and picnic areas.

 

 

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