Fall soil temperatures and moisture content are high enough to cause germination of the grass seed. During the autumn, there is less weed-seedling competition than during the spring.
Rake the broadcasted seeds 1/4 inch into loose soil. Do not leave the seeds sitting on top of the soil -- since it will only feed the birds. Keep the soil moist while the grass seeds are germinating.
Plant the grass seed four to six weeks before the first killing fall freeze. In most climates, this is from August through September. The best grass-seed germination occurs when the soil temperature is above 65 degrees F at a depth of 4 inches.