Prepare the soil. Use a rake to loosen the soil, remove any rocks or debris from the soil.
Plant the grass seed with the seed spreader. You can use a hand-held spreader or walk-behind spreader. Walk in a straight line across the area to spread the seed, and then walk back crossing over the area you just applied the seed to for even coverage.
Rake the seed into the soil. Gently run the rake over the soil and back, to integrate the seed with the soil, but not so deep as to bury the seed more than 1/4 inch into the soil.
Cover the seeded area by spreading a light layer of salt hay over it, allowing the soil to show through the hay. You want to see part of the soil through the hay, otherwise the seeds won't receive enough sunlight and water to germinate. Make sure there aren't any clumps in the hay. Use salt hay because it does not contain the seeds a regular bale of hay contains, or you may end up with a lawn full of weeds.
Place stakes around the area and rope it off to keep anyone from walking on the newly planted seed.
Water the area using an even spray with a hose. You need to water for at least 10 minutes to give the ground a good soaking. The seeds need this extensive initial watering to begin the germination process. An even spray of water helps prevent soil erosion, which can occur when uneven jets of water hit the grass layered with hay.
Check the area daily during extremely hot temperatures. Do not allow the soil to dry out. If the seeds dry out too much, they will have trouble germinating. Water daily for the first two to three weeks or until the grass begins to grow.
Pick up the hay as the grass begins to grow. This allows the roots in the grass to receive enough sunlight to continue to grow.