The time has arrived for those who have a desire or need for their Southern lawn to be green throughout the winter? Overseeding should be done when soil temperatures reach around 70 degrees which as a general rule will occur around the middle of October for much of Mississippi.
Good reasons for winter overseeding lawns in Mississippi are rather limited. The first is the need to provide some type of ground cover for a new home site where it is too late in the fall to establish a permanent lawn. Another may be that you have had your permanent lawn damaged in some way that it will be vulnerable to additional winter injury if not overseeded. Perhaps for special events such as early outdoor spring weddings, parties, etc. that require a lush green setting. And lastly, you simply must have a green lawn all year. Although this is a somewhat questionable good reason as overseeding strong healthy permanent lawns with cool season grasses will delay spring transition and can possibly thin the permanent turf. Therefore, consideration should be given to a strategy of removing the ryegrass once spring transition of the permanent lawn begins as the overseeded ryegrass then becomes a competitive weed. The newer sulfonyl-urea class of herbicides has made this a much easier task.
The turf species of preference for winter overseeding warm season turf species lawns should be perennial ryegrass. Perennial ryegrasses are much finer textured than annual ryegrass cultivars, generally have much better color throughout the winter, not as prone to clumpiness, and do not produce as many unsightly seed stalks in the spring. Seeding rate for home lawns with perennial ryegrass should be 8-10 pounds per thousand square feet. If you opt for the less expensive but also much less desirable annual ryegrass increase this by another 2 pounds.
Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. firstname.lastname@example.org