There are several important factors to consider before seeding a new lawn. First you'll need to select a grass seed mix that matches your needs. If you have kids, a durable, traffic-resistant blend is essential. Estimate how much of your lawn is in sun and how much in shade, then visit the local garden center or nursery to see what grass seed mixes are recommended for your area and conditions. Cool season grasses are best planted in the fall when the nights are cool. Warm season varieties should be planted in late spring or early summer.
Test your soil to find out the pH level. Most turfgrasses need a pH level between 5.8 and 6.5. You can raise your pH with application of lime or lower using sulfur. In either case, you should get experienced advice to make sure the amount applied is correct. Your local county extension office can provide this information.
Remove all weeds, plants and other debris from the planting area including roots. Large stones should also be taken away. Even out the surface with a garden rake. If there are obvious low spots, have some soil brought to make the lawn as level as possible.
Smooth and firm the surface with the water-filled hand roller. Rake in the same direction across the whole area to make shallow channels spaced several inches apart. This will make it easier to work the seed into the soil. The channels should only be 1/4 inch deep.
Divide your seed mix into two halves. Lay half of the grass seed by making passes with the broadcast spreader. Change direction to cross-seed the area with the rest of the mix.
Rake the soil gently over the seed to cover it. The seed only needs to be 1/4 inch deep. Roll the lawn again to firm the soil and ensure good contact with the seed.
Water the lawn with a fine spray and keep it moist at all times during the first month after seeding. This is important to ensure a good germination rate. When the grass seed sprouts, the watering can be increased to 1 inch per week which should be given in one application.
Mow for the first time after the grass has grown at least one third higher than the intended cutting height. Only cut the lawn when it is dry to avoid damaging the young grass.
Apply an organic nitrogen fertilizer at the recommended dosage about six weeks after the seed has germinated and make regular applications in spring and fall.