Annual (Italian) Ryegrass is primarily used for pastures and quick cover in erosion control plantings. In the south, it is used as a winter annual for overseeding warm season grasses.
Lolium perenne spp. Multiflorum (Lam.) Husnot, Annual Ryegrass is quite similar to perennial ryegrass except it is an annual or biennial, depending on climate and/or length of growing season. It may grow a little taller than perennial ryegrass, from 2 to 3 feet tall. Annual ryegrass is a bunch-grass, with numerous long, narrow, stiff leaves near the base of the plant. The under surfaces of leaves are bright, glossy, and smooth. Inflorescence stems are nearly naked. There are approximately 224,000 seeds/pound.
These grasses have a wide range of adaptability to soils, but thrive best on fertile soils with a pH between 5.5 and 6.5. They produce well in regions having mild climates. They do not withstand hot, dry weather or severe winters. They will stand fairly wet soils with reasonably good surface drainage. Annual Ryegrass is distributed throughout the entire United States.
Annual ryegrass seed should be planted ¼ to ½ inch deep in a well prepared seedbed. Spring seedings of annual ryegrass seed may occur in March, April, or May. Annual Ryegrass may also be seeded mid-August to early November, depending on the location. Generally, a rate of 30 to 40 pounds per acre is used if ryegrass is seeded alone. In mixtures, 6 to 10 pounds per acre is recommended, depending upon uses and companion species. In general, the annual ryegrass seed component of a mix should be 20% or less since it is very competitive, due to rapid germination and good seedling vigor.
Ryegrass is generally cut for hay when seed heads start to emerge. Pastures should be rotationally grazed when spring growth is 3 to 6 inches high. Allowing 7 to 10 inches of regrowth between grazings will benefit yield and persistence. On new seedings, harvest or grazing should be delayed until plants are 10 to 12 inches tall. Ryegrass responds well to good management, such as intensive rotational grazing and fertilizer applications.