February 11, 2009

Perennial ryegrass, annual ryegrass, Italian ryegrass, and even cereal rye. It's enough to confuse anyone who is making a selection. Following is a quick primer on the characteristics of these ryegrasses to help growers select the right one for their needs and conditions.

Italian ryegrass (Lolium perenne L. ssp. multiflorum (Lam.) Husnot)

Perennial ryegrass may be the highest quality perennial grass in the world and is used widely in many mild climates; however, it does not like hot, dry summers or dry winters and does not survive well in our climate. Use it only in mixtures for short-term use with animals that respond well to high quality pasture, like dairy cows or stockers.

Annual ryegrass is available in two types: Westerwold and Italian.

Westerwold is the more traditional annual ryegrass. It grows rapidly after spring planting but goes to seed in early summer. If grazed or clipped, it usually regrows, although slowly, and forms seed heads again. It will not survive winter. Westerwold is used best as an emergency forage.

The other type of annual ryegrass is Italian ryegrass. The best varieties act like biennials - they don't form seed during the year of planting, but instead, go to seed the next spring and often die. After planting, they start growing quickly in June and continue growing rapidly until frost. All the growth is high quality leaves. Winter survival is not dependable and varies from year-to-year and by variety.

The confusion regarding these two types of annual ryegrass becomes even more complicated because botanically, Westerwold ryegrass can also be called Italian ryegrass. That's why it's important to be specific and select your ryegrass seed carefully to ensure you're getting the product you intended. If you want one that acts like a biennial, be sure to ask for it that way. With the right type, ryegrass can provide outstanding feed.

Bruce Anderson
Extension Forage Specialist