What kind do you need? Will it be heavily used for group sports, play by children, or exercise for dogs? Or is it intended not for foot traffic, but simply as a lush, fine-textured green plot in the overall landscape?
When preparing the area to be planted, make sure it has a gentle slope away from buildings and other areas that could be damaged by standing water. In general, allow a 1-foot slope for every 100 feet of distance.
Test and amend the soil as you would in any other garden area. Because grass forms a thick mat about 1 inch high, the prepared planting area should finish out at about an inch lower than surrounding areas.
Lawns started from seed are best planted in fall, early enough in the season to give the grass time to establish before cold weather comes.
When you prepare the soil, don’t cultivate it too finely – it may crust, forming a hard surface which emerging seedlings cannot penetrate. Ideally, aim for pea-size to marble-size soil particles.
Planting & Fertilizing
Pick a windless day and sow seed evenly, using a drop or rotary spreader. Apply a complete dry granular fertilizer (like 16-16-16), also using a spreader.
Cover seeds by dragging the back of a lightweight leaf rake over the area or applying a thin (1-inch) mulch. Mulching is the better option if you expect hot, dry weather or drying winds. Use an organic mulch, but not peat moss or sawdust.
Water thoroughly, taking care not to wash away the seed. Then keep the seeded area moist for about 3 weeks or until all grass is sprouted, watering briefly (in 5- to 10-minute spells) and frequently. You may need to water 3, 4, or more times a day during warm periods.
Mow for the first time when the grass is one-third taller than its optimum height. Mow slowly to keep from disturbing the barely set roots. After the initial mowing, continue to water frequently; the top inch of soil should not be allowed to dry out until the lawn is well established (this usually takes about 6 weeks and 4 mowings).
Try to avoid walking on the lawn too much during the initial 4 to 6 weeks.