Grass seed is spread in late summer or early fall to allow the seed to establish before the following summer, and the grass is allowed to grow until it is four to five inches tall. Grass seed is watered lightly several times daily when planted in hot weather.
To ensure grass seed establishes, the existing grass is cut much shorter than usual, and the grass clippings are removed. Adding less than a quarter-inch of soil to the lawn allows grass seed to establish easily. Slice seeding is recommended for rebuilding the lawn when the lawn is too thin or when it is covered by a heavy thatch.
If reseeding spots killed by grubs, apply a grub insecticide, and wait a week or two before reseeding. Apply a starter fertilizer at the time of seeding to help the young grass grow. Mulch the area, and keep the ground moist, even if you must water it more than once a day. Do not use herbicides on the reseeded lawn, and wait at least three weeks before mowing it.