A native of Europe, and now widespread throughout the United States.
Normally an annual grass weed, but under moderate climates it may behave as either a biennial or a short-lived perennial. This introduced grass is used to over-seed bermudagrass lawns in the winter, when Bermuda grass dies back and the ryegrass provides green turf until the bermuda re-grows.
It also grows readily on any other soil condition, including in crops, roadsides, landscape, and in turf when not wanted. Seeds germinate through the spring and again from late summer into the fall.
Mature plants grow as high as 3 feet, and plants tend to form clumps. The stems are reddish at the base, as are the sheaths at the base of leaves. Within the bud the leaf is rolled, distinguishing Italian ryegrass from perennial ryegrass, in which the leaves are folded in the bud.
Leaves are hairless as is the sheath, but tiny projections (auricles) are present at the base of the leaf.
Seeds are produced on long stalks at the ends of the stems. Stalks may be over 12 inches long, and seeds occur in groups alternate along the stem. Short awns are present, and there are from 10 to 20 seeds in each group.
Characteristicts Important to Control:
A cool season grass, with germination prior to the onset of cold weather.