Kentucky Bluegrass
Plant Guide
KENTUCKY
Rehabilitation: Kentucky bluegrass is included in
seed mixes that are used to revegetate roadbanks. It
BLUEGRASS
is a slow-growing plant, establishes in 2 to 3 years
and forms a dense sod. It is not as good at stabilizing
Poa pratensis L.
soil as its native counterparts.
Plant Symbol = POPR
Wildlife: Elk, mule deer, and bighorn sheep eat
Kentucky bluegrass. It is an important winter forage
Contributed by: USDA NRCS National Plants Data
grass for these animals in the west. Cottontail rabbit,
Center
wild turkey, and prairie chickens consume the leaves
and seeds of Kentucky bluegrass. In the mountain
meadows of Oregon, the northern pocket gopher,
mice, and Columbian ground squirrel feed off of the
dominating Kentucky bluegrass. Therefore this is an
important habitat for foraging raptors. Kentucky
bluegrass also provides cover for small mammals and
nongame birds.
Legal Status
Kentucky bluegrass is listed as an invasive weed in
the Great Plains States and Wisconsin. Please
consult the PLANTS Web (http://plants.usda.gov)
site and your State Department of Natural Resources
for this plant’s current status (e.g. threatened or
endangered species, state noxious status, and wetland
indicator values).
J.M. Randall @ TNC. 2003.
Weediness
This plant may become weedy or invasive in some
regions or habitats and may displace desirable
Alternate Names
vegetation if not properly managed. Please consult
June grass, Paneion pratense, Poa anceps,
with your local NRCS Field Office, Cooperative
Poa angustifolia var. pratensis, Poa angustifolia var.
Extension Service office, or state natural resource or
angustiglumis, Poa pratensis var. macounii, Poa
agriculture department regarding its status and use.
pratensis var. pinegensis, Poa pratensis var. stricta,
Weed information is also available from the
Poa pratensis var. transnominata, Poa pratensis var.
PLANTS Web site at plants.usda.gov.
urjandhaica, Poa pubescens, Poa urjanchaica, Poa
viridis, smooth meadow grass, spear grass.
Description
General: Grass Family (Poaceae). Kentucky
Uses
bluegrass is a cool-season perennial sod-forming
Landscape: Kentucky bluegrass is a popular sod-
grass. The roots are shallow, often within the upper 8
forming grass that is used on golf courses, ski slopes,
cm of the soil surface. Stems are 30 to 90 cm tall.
and campsites.
Leaves are attached to the base of the stem, folded
and sometimes hairy at the point of attachment, have
Livestock: Kentucky bluegrass is an important forage
flat blades, are 2 to 5 mm wide and 10 to 40 cm long.
species for sheep and cattle. In the west, it is very
The inflorescence is an open panicle consisting of
abundant and frequently used as a forage crop. In the
two to six flowers. The lemmas have a tuft of
east, it is planted as a pasture grass. It is not usually
cobwebby hairs. Flowering starts in May and fruit is
used for hay, but it has been found as an invader of
mature by mid-June.
hay mixes.
Kentucky bluegrass is distinguished from Canada
bluegrass (Poa compressus) by its darker green
Plant Materials <http://plant-materials.nrcs.usda.gov/>
Plant Fact Sheet/Guide Coordination Page <http://plant-materials.nrcs.usda.gov/intranet/pfs.html>
National Plant Data Center <http://npdc.usda.gov>
foliage, longer leaves, and pubescence at the bases of
the leaves.
Kentucky bluegrass is intolerant of drought,
excessive flooding, high water tables, and poorly
Distribution: Kentucky bluegrass is native to portions
drained soils.
of North America, including areas within the United
States. Exact delineation of native status has not
Establishment
been determined, but data seems to indicate that it is
For lawn establishment, plant 2 to 3 pounds of seed
native in parts of the southeast, northeast, and upper
per 1,000 square feet. Seeding rates are reduced
Midwest regions and introduced or naturalized
when seed is drilled into the top 1 inch of soil.
elsewhere. It occurs throughout the United States
Kentucky bluegrass can be seeded year-round, but
although it is most prevalent in the northern half. It
the best results are obtained in the spring and fall.
is not common in the Gulf States or in the desert
Seeds require light and frequent watering (2 to 3
regions of the southwest. For current distribution,
times per day for the first 2 weeks) for germination to
please consult the Plant Profile page for this species
occur. After seedling emergence, watering frequency
on the PLANTS Web site (http://plants.usda.gov).
can be reduced.
Habitat: Kentucky bluegrass is promoted on sites
Management
that have cool and humid climates. It is found in
The active growth stage of Kentucky bluegrass
uplands and lowlands of the tallgrass prairie and in
begins in late winter/early spring. By midsummer, it
the lowlands of mixed-grass prairies where adequate
is nearly dominant on its sites. Cool temperatures in
precipitation falls. In the west, it is found on
fall promote growth when other species are dying
northern exposures at mid to high elevations. In the
back. It spreads by rhizomes, produces abundant
southwest and California, it is found in cool
seed, and can become established on disturbed sites
mountainous regions.
faster than other plant species. It is an aggressive
competitor with native species.
It frequently occurs as an understory dominant in
aspen habitats throughout the Intermountain Region,
Total replacement of Kentucky bluegrass by natives
ponderosa pine, sagebrush/bunchgrass, and
is labor-intensive and impractical. It is best to
bunchgrass habitats throughout the U.S., and riparian
manage for warm season native grasses rather than
habitats in the Mountain West. It is also a common
against Kentucky bluegrass. In grasslands, atrazine
dominant of Midwestern prairies.
and glyphosphate are effective herbicides for
decreasing Kentucky bluegrass abundance when
Adaptation
applied prior to seeding warm-season native grasses
Kentucky bluegrass is found most abundantly on sites
like big bluestem. Also, irregular spring and fall
that are cool and humid. It has become naturalized
burns can help to control or maintain co-dominance
across North America and often occurs as a dominant
of Kentucky bluegrass (as opposed to complete
species in the herbaceous layer.
dominance).
Kentucky bluegrass grows best on well-drained
Kentucky bluegrass pastures are best managed under
loams or clay loams rich in humus and on soils with
a grazing system other than season-long use. At the
limestone parent material. It needs large amounts of
end of the growing season, it becomes less palatable
nitrogen during active growth stages. The optimal
and protein and fiber contents decline.
soil pH is between 5.8 and 8.2.
Pests and Potential Problems
In the Blue Mountains of eastern Oregon and
White grubs, billbugs and sod webworms can destroy
southeastern Washington, Kentucky bluegrass
plantings of bluegrass. Insect populations should be
dominance is an indicator of dry to moist meadow
monitored so that timely insecticide applications can
conditions and of soils that are dark brown to black
be made. Pest management in this manner is much
and clayey.
more cost effective than routine insecticide
applications or replanting large areas.
Kentucky bluegrass plants that have shorter leaves
are more likely to produce tillers. Plants that occur in
Kentucky bluegrass is sometimes vulnerable to
full sun have shorter leaves while those in shade have
fungal infections including Fusarium,
leaves longer than the stems. Therefore plants that
Helminthosporium, leaf spot, rust and powdery
are in full sun will produce more tillers and spread
more quickly than those in the shade.
mildew. Mixing bluegrass seed with ryegrass will
Randall, J.M. 2003. Image of Poa pratensis.
prevent Fusarium blight.
(http://tncweeds.ucdavis.edu/esadocs/poa_prat.html,
23 July 2004). University of California, Davis.
Seeds and Plant Production
Seeds are sown in springtime in a cold frame
Rayburn, E. and J. Hall. 2004. The identification of
containing moist compost. Seedlings are thinned to
grasses
individual pots and moved into a greenhouse where
(http://www.caf.wvu.edu/~forage/library/cangrass/co
they will remain for the first winter. After the last
ntent.htm, 23 July 2004). Department of Agriculture
spring frost, plant the seedlings into their permanent
and Forestry, West Virginia University, Morgantown.
positions. Plant divisions can be directly planted into
their permanent positions in late spring or early
Sather, N. 1996. Element stewardship abstract (ESA)
summer.
for Poa pratensis and Poa compressa.
(http://tncweeds.ucdavis.edu/esadocs/poa_prat.html,
Cultivars, Improved, and Selected Materials (and
23 July 2004). University of California, Davis.
area of origin)
There are over one hundred Kentucky bluegrass
Uchytil, Ronald J. 1993. Poa pratensis.
cultivars readily available by commercial sources.
(http://www.fs.fed.us/database/feis/, 23 June 2004).
Many of these cultivars have been developed for
Rocky Mountain Research Station, USDA Forest
disease resistance, and nutritional content for
Service, Missoula.
livestock.
Wunderlin, R.P., and B.F. Hansen. 2003. Atlas of
Contact your local Natural Resources Conservation
Florida vascular plants
Service (formerly Soil Conservation Service) office
(http://www.plantatlas.usf.edu, 23 July 2004).
for more information. Look in the phone book under
Institute of Systematic Botany, University of South
”United States Government.” The Natural Resources
Florida, Tampa.
Conservation Service will be listed under the
subheading “Department of Agriculture.”
Prepared By:
Sarah Wennerberg
Control
Formerly USDA NRCS National Plant Data Center
Please contact your local agricultural extension
Baton Rouge, Louisiana
specialist or county weed specialist to learn what
works best in your area and how to use it safely.
Species Coordinator:
Always read label and safety instructions for each
Mark Skinner
control method. Trade names and control measures
USDA NRCS National Plant Data Center
appear in this document only to provide specific
Baton Rouge, Louisiana
information. The USDA NRCS does not guarantee
or warranty the products and control methods named,
Edited: 4Aug2004 sbw; 21Oct2004 rln; 060808 jsp
and other products may be equally effective.
For more information about this and other plants, please contact
References
your local NRCS field office or Conservation District, and visit the
PLANTS Web site<http://plants.usda.gov> or the Plant Materials
Agricultural Research Center. 2004. GRIN taxonomy
Program Web site <http://Plant-Materials.nrcs.usda.gov>
(http://www.ars-grin.gov/cgi-bin/npgs/html/index, 26
July 2004). USDA, Beltsville.
The U.S. Department of Agriculture (USDA) prohibits
discrimination in all its programs and activities on the basis of
Dubel, R.L. 2004. Kentucky bluegrass (http://aggie-
race, color, national origin, sex, religion, age, disability, political
horticulture.tamu.edu/plantanswers/turf/publications/
beliefs, sexual orientation, and marital or family status. (Not all
bluegrass.html, 23 July 2004). Texas Cooperative
prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program
Extension, Texas A&M University, College Station.
information (Braille, large print, audiotape, etc.) should contact
USDA's TARGET Center at 202-720-2600 (voice and TDD).
Morris, R. 2002.Plants for a future database
(http://www.scs.leeds.ac.uk/pfaf/index.html, 23 July
To file a complaint of discrimination write USDA, Director, Office
of Civil Rights, Room 326-W, Whitten Building, 14th and
2004). Plants for a Future, Devon, England.
Independence Avenue, SW, Washington, DC 20250-9410 or call
202-720-5964 (voice or TDD). USDA is an equal opportunity
provider and employer.
Read about Civil Rights at the Natural Resources Convervation
Service.
