There are two main types of ryegrass. Annual ryegrass (Lolium multiflorum), also called Italian ryegrass, is grown primarily as a forage grass; it is native to southern Europe. There are both turf and forage varieties of perennial ryegrass (Lolium perenne L.) that are native to Asia, Europe and North Africa. Pereinnial ryegrass is the most popular perennial grass worldwide.
Annual ryegrass is a cool season bunch grass. It yellowish-green at the bases and can grow 3 to 4 feet high with glossy leaves that are up to 12 inches long. It is grows well in cool, moist weather and is widely grown in wet coastal areas extending from Northern California to British Columbia. It can tolerate extended periods of rain and temporary flooding.
Uses of Annual Ryegrass
Annual ryegrass is used as forage, hay and to assist in the establishment of legume crops. Since annual ryegrass establishes quickly and grows throughout the fall and winter, it is used as a cover crop to protect the soil and suppress weeds between annual or perennial crops. Because it tolerates wet soil and temporary flooding, it is useful as a ground cover on grass waterways or along ditch banks. It can be grown with little preparation of the soil, making it useful to quickly plant burned areas and bare soil in construction sites.
Description of Perennial Ryegrass
Perennial ryegrass is a bunch grass with stiff, narrow leaves at its base. The tops of its leaves are glossy, bright and smooth. It can grow from 1 to 2 feet tall. Perennial ryegrass cannot withstand severe winters or dry, hot weather; it thrives in rich, dark soils in areas with a mild climate.
Some varieties of perennial ryegrasses are diploid, meaning they have two sets of chromosomes. Other types are tetraploids, meaning they have four sets of chromosomes. Diploid varieties of perennial ryegrasses have a finer texture than tetraploid grasses. Tetraploid grasses have wider leaves, plus larger seedheads and side shoots; they are also taller and less dense than diploid varieties.
Uses of Perennial Ryegrass
Diploid varieties of perennial ryegrass are grown as a fine-textured, shiny green turf. Perennial ryegrass turf is tough and wears well making it popular for baseball fields, athletic playing grounds, parks and other public areas. It is sometimes added to Kentucky bluegrass to give strength to the Kentucky bluegrass; it forms a dense sod similar to Kentucky bluegrass and is mowed at the same height.
Tetraploid varieties of perennial turfgrass is useful for pastures with heavy animal traffic It is useful for for pastures suffering from heavy rains or quick meltdown of snow. It is used to overseed pastures that go dormant or grow slowly during the winter.
Ryegrass Grown as Turf
Both annual and perennial ryegrasses grown as turf should be cut no closer than 3 inches from the grown. Perennial ryegrass grown as turf may be mown infrequently but closely. Perennial ryegrass is more difficult to establish and grows more slowly after it is sown.