Annual ryegrass adaptability, quick establishment, and aggressive growth are also considered to be characteristics of a weed. The annual ryegrass we know as a cover crop is the same species as Italian ryegrass, which has become a major pest in both the southern Mississippi Delta and Pacific Northwest. This species’ aggressive growth aspects and its ability to adapt to herbicides has made many weed scientists cautious about recommending it as a cover crop. While annual ryegrass has shown to be an excellent cover crop it is also the most difficult grass cover crop to terminate, so should only be grown by experienced cover crop users. This publication provides general guidelines for successful termination of annual ryegrass with herbicides using data acquired at Purdue University.