Annual ryegrass grows well in cool and wet climates. It germinates easily, within a week of planting if moisture is present. In the Midwest, annual ryegrass grows a massive root network – to depths of more than 60 inches over the winter, especially after successive years of no-tilling. This is especially valuable because corn and soybean roots will follow in the path that annual ryegrass roots establish. This gives plants an advantage in dry years, finding moisture and nutrients in deeper soil.
For many decades, annual ryegrass has been a preferred forage crop for livestock. It is also used to overseed acreage in warmer climates during the winter, when native grasses are dormant. Increasingly, annual ryegrass is used as a winter cover crop in the Midwest, to improve soil conditions and speed up the process of converting from conventional to no-till.