There is annual ryegrass and the perennial ryegrass and you can over seed Bermuda or St. Augustine with that. October is the best time to apply the ryegrass seed. The application rate is usually anywhere between 5 and 10 pounds for 1000 sq. ft. It's best to use a broadcaster to spray the seed and then be sure to water it in. You want to water pretty much everyday for about a week to try and get that ryegrass to sprout up. You should see the ryegrass in about two weeks. There are some advantages and some disadvantages. The biggest advantage is that the ryegrass is aesthetically pleasing. You are going to have to mow it regularly in the winter, every seven days, and in the springtime, depending on which rye you choose. The annual rye doesn't die very quickly in the springtime. So, it is still growing when the St. Augustine is coming out of dormancy. There is only a period for about a month where your grass is transitioning from your ryegrass to your St. Augustine, so initially it gives kind of a dead look to your yard. As long as you don't have a problem with that, over-seeding is fine. The perennial ryegrass has a shorter stay. It doesn't get as tall and it's not a true perennial, so it doesn't come back year-to-year. Most people use it, but it grows short and you won't have to mow it as often. It's twice as expensive, but we don't usually recommend that you use perennial ryegrass with St. Augustine, because it will compete too much with the St. Augustine. The perennial rye has a tendency to keep growing and growing and if it's a cool winter, it will keep growing to the point where it may choke out some of your St. Augustine.
