St. Augustinegrass makes a beautiful, vibrant lawn. However, there are disadvantages to this variety. It is likely to fall victim to freeze damage, is prone to a spongy turf, suffers from many pest problems and is vulnerable to turf buildup. Weed issues are usually hidden pretty well by the coarse texture, but eventually become obvious. To repair St. Augustinegrass, you need to remove the dead areas and replant seed.
Buy St. Augustinegrass seed to match the current lawn. Even though there are other grass varieties that may grow better, they will not match the color and texture of the rest of your yard.
Rake the dead portions of the lawn with a metal rake. The goal is to remove as much of the dead grass and roots as possible.
Till the top 4 to 6 inches of earth to loosen it up. Pick up and remove debris such as weeds and rocks.
Apply 1 inch of topsoil or peat moss to the top of the planting area. Work it in with the rototiller to thoroughly combine it with the local soil.
Spread St. Augustinegrass seed with a hand spreader for small areas and a mechanical spreader for large spots. Use the directions on the seed bag to determine how much seed to drop.
Cover the grass seed with straw if you live somewhere that gets heavy rain. If not, work the seeds gently into the top of the soil with a rake, to lightly cover them with about 1/4 inch of soil.
Press down on the soil with your shoe to push the seeds into the ground. Water the seeds to keep them consistently moist until they root, which typically takes 10 to 14 days.