Overseeding warm-weather grass turfs with annual ryegrass creates a green lawn year-round. According to the Alabama Cooperative Extension Service, a Bermudagrass lawn is the recommended warm-weather grass that tolerates ryegrass introduction and overseeding. Zoysia and centipede grasses may be damaged by overseeding of the cool-weather annual. The best time to overseed a warm-weather lawn is in late October through November, or after the first frost.
Mow the existing warm-weather grass at the lowest setting on the lawn mower. This will improve the seed-to-soil contact and sunlight requirements for ryegrass seed germination. One exception to this low-mowing is St. Augustine grass--never scalp-mow this type of turf grass.
Broadcast the annual ryegrass seed over the lawn at a rate of 10 to 12 lbs. per 1,000 square feet.
Apply the 18-6-12-lawn fertilizer to the lawn immediately after the seed is planted at a rate of 5 lbs. per 1,000 square feet.
Irrigate the lawn with the garden hose and sprinkler. Water the area lightly two to three times a day. Keep the seeds moist until germination begins. Full germination of the seed may take several weeks.
Mow the ryegrass to a height of 2 to 2 ½ inches. Fertilize the lawn with 2 lbs. of the 18-6-12 per 1,000 square feet every three weeks for a dense, healthy stand of green grass.