The first step to sowing grass seed is determining the best time to plant grass. Although grass seed can be planted in the spring with good results, most gardening experts recommend planting it in early fall, before the first frost. The season, however, is not the only factor that should determine when to plant grass seed. There are other considerations as well.
Plant grass seed when the ground is moist. Seeds germinate best in consistently moist soil. Damp soil is also easiest to work with. The first step in planting grass seed is to till the soil. Many gardeners mix mulch and fertilizer into the soil as they break it up. It is much easier to break up the soil for the grass seeds if the soil is slightly wet. Wait for a clear day after it has rained, in early autumn, before a hard frost has frozen the ground. Do not choose a day after a heavy rain, as muddy soil is much harder to work with, and standing water can cause seeds to rot. Also avoid sowing grass seed before a forecast of heavy rain, as strong rains can wash away newly planted grass seeds.
Sow the seeds on a sunny day. Grass seeds also need warm sunlight to sprout. This is another reason why early autumn is a good time for planting grass seed. The weather is still warm enough to germinate the seeds, but it is not so hot that the seeds and soil will quickly dry up. If the weather is hot for an extended period of time, you will have to water very often--up to three times a day--to keep the ground moist and cool for the seeds to germinate. For these reasons, choose a day in early autumn that has warm, but not hot, temperatures.
Wait until the weeds are dying before planting grass seed. If you sow grass seed in the spring, the grass will be competing with fast-growing spring weeds. In the autumn, however, most weeds are dead or dying, which opens up room for grass seeds to grow unhindered.