Perennial ryegrass is a valuable forage and soil stabilization plant. This species is the predominant forage grass in Europe and is used extensively in the United States. Perennial ryegrass is used for pasture and hay in sheep, dairy and beef production. It is often used in mixes with alfalfa, clovers and other grasses. Perennial ryegrass has the highest forage quality of all cool season grasses.
Perennial ryegrass turf varieties are quick and easy to establish, heat tolerant, dark green and have a very fine leaf texture. They make a very attractive lawn although maintenance requirements are higher than other turfgrasses. Perennial Ryegrass is also used for Winter overseeding of bermudagrass lawns in the southern U.S.
Lolium perenne L., Perennial Ryegrass is a bunchgrass which grows from 1 to 2 feet tall, and has medium longevity. There are 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. Seed heads are spikes with spikelets growing edgewise to the seed head stem. Seeds do not have awns (bristles). There are approximately 330,000 seeds per pound.
Adaptation and Distribution
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. Perennial ryegrass is distributed throughout the entire United States.
Perennial ryegrass seed should be planted 1/4 to 1/2 inch deep in a well prepared seedbed. Spring sowing of perennial ryegrass seed may occur in March, April, or May. Perennial ryegrass may also be seeded mid-August to early September. For forage or pastures, a rate of 30 to 40 pounds per acre is used if ryegrass is seeded alone. In perennial ryegrass seed mixtures, 6 to 10 pounds per acre is recommended, depending upon uses and companion species. In general, the perennial ryegrass component of a forage seed mix should be 20% or less since it is very competitive, due to rapid germination and good seedling vigor. Turf seeding rates are 5-7 pounds per 1000 sq. ft. for new lawns, 3-4 pounds per 1000 sq. ft. for established lawns and 30-35 pounds/1000 sq. ft. for overseeding.
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. When used for turf, mowing height should be 1-2”. Mow frequently enough so no more than 1/3 of the total leaf area is removed. Perennial ryegrass requires moderate to high watering and moderate to high fertilizer requirements. Disease control measures may be needed depending on conditions during the growing season.