Ryegrass is available in one of two forms: annual or perennial. Annual ryegrass, also called "Italian" or "English" ryegrass, originates from Europe and is adapted to a variety of weather conditions. Annual ryegrass is used as a cover crop to prevent soil erosion, overseeding of lawns and as a foraging crop. Planting annual grass seed has little requirement.
Annual ryegrass requires long seasons of cool and moist weather. The annual grass seed will germinate in cool soils that other cover crops will not, says Oregon State University. Annual ryegrass prefers areas that have a minimum temperature of above 10 degrees Fahrenheit.
Annual ryegrass prefers a well-drained soil with a pH level of between 5 to 8, ideally being between 6.0 and 7.0. It grows best in an area that has full sun, but it is also shade tolerant.
Annual ryegrass seeds are seeded into warm season grass in the fall, says the University of Maryland. Ryegrass then germinates during the winter months. Seeds begin grass growth once the weather changes in the spring. Winter ryegrass peaks in growth between the mid-winter and into the spring when used as a winter forage.
Seeding rate depends on what the annual ryegrass is used for. Ryegrass, in all situations, requires a high seeding rate. Seed rate ranges between 9 to 40 pounds of ryegrass seed per acre. Seeding is done between mid-September and mid-October. Seed drilling to a depth of 1/2 to 3/4 of an inch deep ensures the best establishment.
Annual ryegrass is best rotated with another cover crop or forage on an annual basis. When used as a cover crop, it is best grown in mixtures of legumes. Ryegrass suppresses weeds, protects the soil from erosion and becomes a part of the soil composition once it deteriorates. Annual ryegrass will reseed itself when mowed. To kill off ryegrass and start a new crop, herbicides are often required.