In Florida, lawns are often over-seeded with annual ryegrass in the fall. Florida lawns planted with warm season grass are lush and green during the warm spring and summer months. But as the temperatures dip, many warm season grasses go dormant and turn brown and unsightly. Ryegrass is a cool season grass. When planted on an existing warm season lawn, it will provide color during the cooler fall and winter months. Then it will die back in the spring when warm season lawn grass comes to life again.
Rake your lawn to remove any loose debris on its surface.
Mow the lawn as low as your lawnmower's blades will grow. Catch all of the clippings in your lawn mower's attached bag or rake them up after you have finished mowing. Do not mow St. Augustine grass lower than 3 inches.
Spread 10 lbs of annual ryegrass per 1000 square feet of lawn. Scatter half of the seed over the ground by hand while walking over the lawn in rows in one direction. Then spread the second half of the seed while walking in rows at a 90 degree angle to the first rows. For best coverage, use a mechanical seeder. Sow half the seed as you walk in one direction, and the other half by walking at right angles to the first.
Sweep the grass with a stiff broom to help the seed penetrate through the grass and come into contact with the soil.
Water the freshly-seeded lawn with 1 to 2 inches of water. Use the gentle spray from a hose or sprinkler system so that you do not disturb the seed as it germinates. Keep the top few inches of the soil moist by watering once or twice daily until the seeds have germinated in 7 to 10 days. Then continue to water daily (using the same amount) for the next 3 weeks until the seedlings establish themselves. Then reduce watering to an as-needed basis when the grass begins to show signs of wilting.
Repeat steps one through five annually in the fall.