orchardgrass (Dactylis glomerata)
Dactylis aschersoniana Graebn.
TAXONOMY: The currently accepted scientific name of orchardgrass is
Dactylis glomerata L. Several varities have been recognized; for the Nature
Guide, variety glomerta will be used (it is by far the most common variety
of Dactylis glomerata).
NATIVE STATUS: Introduced, United States and Canada.
Orchardgrass was introduced to the eastern United States from Europe in
1760. It is widely planted in the United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: Orchardgrass is a
cool-season, perennial bunchgrass, 1.4 to 4 feet (0.5-1.2 m ) tall with erect, glabrous culms and blades 4 to 16 inches (10-40 cm) long and 0.1 to 0.5
inch (0.2-1.1 cm) wide. The inflorescence is a panicle with two to six
florets per spikelet, with the spikelets tightly clustered on one side of the
branch. Orchardgrass is nonrhizomatous. Most root development is in
the upper 3 inches (8 cm) of soil but extends to at least 18 inches (46 cm)
below the surface, producing a dense sod of medium-sized roots.
REGENERATION PROCESS: Orchardgrass reproduces largely by seed
and by tiller formation. The relatively large seed does not have an innate dormancy. Seed can germinate in either light or darkness; germination is
largely controlled by moisture availability, and most seed germinates in the
fall. Thus, orchardgrass does not tend to build up seedbanks in the soil.
HABITAT TYPES: An introduced species, orchardgrass is not generally
used for habitat typing.
SITE CHARACTERISTICS: Orchardgrass is best adapted to well-drain-
ed, rich or moderately fertile soils with an adequate water regime (12 inch-
es or more annual precipitation [30 cm]) and temperatures that are not
extreme. Optimum top growth is achieved at temperatures of approx-
imately 70 degrees Fahrenheit (21 deg C). Orchardgrass is shade tolerant
and does well at higher elevations in the western United States and Canada
(4,900 to 6,200 feet [1,500-1,900,m]). It is widely planted in the eastern
United States, most notably in Pennsylvania, Maryland, and West Virginia.
SEASONAL DEVELOPMENT: Orchardgrass begins growth early in
spring and flowers from May to September or October. In dry areas it is
dormant in summer, but will add new growth in the fall, and will flower
again in fall under appropriate conditions. A green basal rosette is main-
tained through winter. Flowering appears to be temperature rather than
light dependent. Seed shattering takes place in late summer; most seed
will germinate in fall as there is no innate dormancy.
GENERAL DISTRIBUTION: Orchardgrasss occurs in all states in the
United States and all Canadian provinces (except Saskatchewan and
the upper most regions of the Territories).
SKY MEADOWS DISTRIBUTION:
Grass specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
The specific distribution of orchardgrass has not been determined.
IMPORTANCES AND USES: Orchardgrass is moderately nutritious
and highly palatable to deer, elk, bighorn sheep, cattle, and domestic sheep
and goats. The persistent, green, basal rosette provides good winter forage
for deer and elk. Early spring growth provides green forage for all species.
Cattle will eat orchardgrass preferentially in early spring and summer, up
to 50 percent of total diet. Elk and mule deer also prefer orchardgrass over
a number of other species. In areas disturbed by fire where orchardgrass
has been seeded (usually in a mixture with other grasses and forbs), wild-
life use increases over nonseeded areas and nonburned areas. Forest open-
ings, where orchardgrass is dominant, are associated with rufous humming-
birds, pine siskins, slate-colored juncos, American robins, valley pocket
gophers, desert harvest mice, deer mice, Mexican voles, and white-tailed
deer. Grasshopper sparrows and eastern meadowlarks were more abun-
dant in cultivated fields in Georgia codominated by orchardgrass than in
fallow or natural fields. Wild turkeys graze orchardgrass in winter, and
poults use it as a source of cover and insects in late summer. Rabbits use orchardgrass for food and cover; Canada geese feed on the seeds and leaves.
Orchardgrass is widely recommended and used for a variety of rehabilita-
tion applications. It is recommended for planting with a mixture of grass-
es and legumes to reduce erosion after devegetation by fire. Orchardgrass
often shows early success, eventually being replaced by native vegetation
or other seeded species.
Orchardgrass is used in seed mixtures with other grasses and forbs (usual-
ly clover or alfalfa) for rehabilitation of overgrazed lands. The success of orchardgrass appears to depend on the appropriateness of the site to specif-
ic adaptations of orchardgrass cultivars, and also on proper management
Orchardgrass is planted in areas that have been logged and burned to
provide a vegetative cover for soil stabilization and provide forage for
cattle and/or wildlife.
Orchardgrass is also used for rehabilitation of sites disturbed by mining.
The most successful applications in the western United States appear to
be sites that are relatively cool and moist (upper elevations, shaded areas,
Plantings of orchardgrass mixtures do well where there is adequate
moisture (12 inches or more annual precipitation) and where tempera-
tures are not extreme. In the drier western states it is better adapted for
higher elevations or in irrigated pastures and croplands. However, in
the northeastern United States, particularly the southern part of the region, orchardgrass is so well adapted that it will invade alfalfa stands (Medicago
Some cultivars are more drought resistant than others. The following list
of cultivars indicates the wide range of strains available; there are many
more cultivars available--new ones are still being listed.
'LATAR' is a late-season strain, highly recommended for pasture and hay
production; it is 10 percent higher in digestibility than other cultivars and
is more compatible with legumes, especially alfalfa (Medicago sativa).
'POTOMAC' is an early-season strain, better adapted to mountain sites.
'PAIUTE' is more drought tolerant than other cultivars.
'POMAR' is a specially adapted low-growing strain particularly suited as
a cover crop in orchards and for road bank stabilization.
Orchardgrass is a widely planted pasture grass and is used to increase
forage production on rangelands. It is frequently part of mixtures that are
seeded in mountain brush, especially Gambel oak (Quercus gambelii)
types to improve rangeland. These mixtures are drilled or broadcast seed-
ed after some type of surface preparation--usually removal of brush by
burning or chaining, or by herbicide application. Orchardgrass is used to
stabilize ski slopes in Montana and to suppress annual weeds.
Crooked Run Valley