Illustration. Artist unknown. Hitchcock-Chase Collection of Grass Drawings, courtesy of the Hunt Institute for Botanical Documentation, Carnegie Mellon University, Pittsburgh, Pa., on indefinite loan from the Smithsonian Institution
Agrostis stolonifera L.
Scientific Name Synonyms:
Agrostis alba L.
Life Span: Perennial
Origin:Introduced (from Europe)
Growth Characteristics: Redtop is a vigorously rhizomatous grass, growing up to 3 feet tall with stems often decumbent at base, usually producing a coarse, open turf. It starts growth in the early spring, flowers in early summer, and seeds are mature by August. It reproduces from rhizomes, stolons, and seeds.
Seedhead:Open, upright, pyramidal panicle, 4 to 8 inches long, purplish-red when in blossom; panicle branches whorled at lower rachis nodes; spikelets very small, numerous, each containing one small seed; lemmas awnless or rarely short-awned.
Leaves: Mostly glabrous; leaf blades 1/8 to 3/8 inch wide, 2 to 7 inches long, rather stiff, flat, and pointed at the tip, with distinct veins above. Margins are somewhat finely barbed; leaves rolled in the bud; ligules 1/8 to ¼ inch long; membranous, bluntly pointed or rounded, and with toothed to split margins; auricles absent.
Redtop is an introduced plant with wide adaptations to Utah wet and semi-wet meadows, riparian areas, and irrigated pastures. It can withstand flooding for extended periods. It is found at elevations from 3500 to 8500 feet with 18 inches of precipitation or inflow water equivalent.
Redtop rapidly colonizes moist areas disturbed by logging, excessive trampling, construction and flooding.
Soils: It does best in moderately well-drained loamy soils; tolerant to high water table and periodic irrigation. It will grow on acidic soils, and is moderately salt tolerant.
Associated Species: Kentucky bluegrass, timothy, Nebraska sedge, water sedge, and wirerush.
Uses and Management:
Redtop provides fair to good forage for big game in the spring and summer. The dense cover can provide cover for small mammals, waterfowl, and other birds. It is an important commercial forage species, providing good to very good forage for horses and cattle, fair to good for sheep. The species is often cultivated as hay because of its tolerance to mowing and grazing, good cold resistance, and heat tolerance. Grazing usually favors this species.
Redtop forms a dense sod which provides good surface erosion control, but because the roots are shallow, redtop provides limited protection to streambanks and usually does not form the stable overhanging banks desired for fish habitat. Banks vegetated by redtop often fail, falling into the stream as they are undercut by flowing water. In these areas, it is best to change management to promote the growth of riparian species such as sedges which have the root systems capable of holding the banks.