Don't like the look of your brown Bermuda lawn during winter? There's a simple solution: overseed it with ryegrass and you'll have a brilliant green lawn all winter long! Both annual and perennial ryegrass are used for overseeding, however most nurseries carry only annual ryegrass because it's cheaper and sprouts 3 times faster. Both annual and perennial ryegrass die out in the spring in warm climates, but the perennial can interfere with permanent lawns because it lives longer in the spring. So, I suggest going with the annual ryegrass.
When to Overseed?
The best time to overseed is when the daytime temperatures in Fall are averaging around 70 degrees F, give or take 10 degrees, and when nighttime temperatures are averaging around 50 degrees F, give or take 10 degrees or so. I recommend a starting point for overseeding with ryegrass about 30 days before the typical first frost date in your area.
Preparing the Lawn for Overseeding
In order for ryegrass seed to germinate (sprout), the seeds will need to come into contact with soil. If your lawn is very dense it'sa good idea to aerate it. If you don't have an aerator, you can rent one from your local tool rental store. If you aerate, make two or more passes over the lawn going in opposite directions.
Before broadcasting seed, mow the lawn as low as possible and catch or rake up grass clippings.
Broadcasting The Seed
To insure even coverage, use a rotary-type walk behind or shoulder-type broadcast spreader to spread the ryegrass seed at a rate of 10 pounds of seed per 1,000 square feet of lawn area. If using perennial ryegrass spread seed at a rate of 5 to 10 pounds per 1,000 square feet.
Note: To measure your lawn for total square feet, measure and then multiply the length by the width of your lawn area(s). For example: If your lawn is 100' long and 50 feet wide, the equation would look like this: 100' x 50' = 5,000 Square Feet.
To ensure even coverage, it's a good idea to broadcast half of your seed in one direction and the other half in the opposite direction.
With sufficient watering, annual ryegrass will usually germinate in 3 to 5 days after sowing. Water the newly seeded lawn every day until the ryegrass seeds germinate. If you have a sprinkler system, set it to run at least two times a day for a short period of time, just enough to keep the soil damp. Avoid overwatering as this can lead to washing of the seed and to disease. Perennial ryegrass can take two to three times longer than annual ryegrass to germinate.
Maintaining An Overseeded Ryegrass Lawn
When the ryegrass has reached 2 to 3 inches in height, mow to remove a third of the height. Repeat this process throughout the winter. After the second mowing you can apply a winterizer/ fall feed lawn fertilizer.
In spring, when temperatures begin to rise above 70 degrees F, start mowing the ryegrass as low as possible. This will cause the ryegrass to start dying out, allowing your Bermuda grass to emerge naturally, on time, and without competition.