The critical elements in successfully applying and germinating grass seed are simple and finite: Prepare the soil well and never let the soil and seeds dry out. Careful management of the seeded area for a period of six to 12 weeks will yield a lush and well-established lawn. And, if over time patches of the seeded lawn become worn or damaged, reseeding can be done with the same simple process, only on a smaller scale.
Grass seed thrives when sowed onto a smooth and levelled bed of well-tilled, moist soil enriched with topsoil, compost and peat moss. Till up the existing soil to a depth of at least 3 inches and preferably 6 inches, removing any stones or hard clods as you work. Smooth down the soil with a rake to level. Apply the layer of new topsoil and amendments at least 1 inch thick and again rake to incorporate. Then, use the back of the rake to level the soil.
Sow the grass seeds by hand in a short, wrist-casting motion or with a mechanical seed spreader. Cover the soil area evenly and heavily, making a couple passes at spreading the seed from different angles to ensure a consistent coating. Grass seed does not have to be buried in soil, but will benefit from being gently raked into the top inch or so of soil. You can also use a weighted lawn roller to compact the soil and seed together. Renting a roller is probably a worthwhile expense if you're seeding a large expanse of lawn, but less so if you're seeding or reseeding a small area.
Water and Protection from Traffic
Water the sown grass seed with a hand sprayer set to a gentle rain or spray pattern. If the soil moves as you water, your stream is too strong. After going to the trouble of laying the seed evenly, try to prevent it from moving it around. Keep the soil and seed evenly moist, but not wet for at least 10 days or until you begin to see green blade shoots. In some climates this may mean watering more than once a day for the first week or so. Keep a daily watch on your seed and maintain a dark, moist soil at all times to ensure good germination rates. Cordon off the seeded area with stakes and twine to prevent humans and animals walking on it. Eliminating compaction of the soil during germination will allow roots to form more readily, which mean the lawn will establish itself more quickly.