There are three ways to plant grass: with seeds, sod or plugs. Seed lawns in late summer, early fall or in April or May. Soil needs to be warm when seeded. Seeding will take more time to grow a lawn. Sod is more expensive than seed, but will create an instant lawn. Sod can be put down at any time. Plugs are usually used in warmer climates at any time.
Once you have chosen grass seed, the first step is to get the soil ready. For a new lawn, loosen the top 2 to 3 inches of soil. Remove all debris, including stones. Break up soil clumps and level areas where water might stand. After seeding, fertilize. Avoid using weed killers.
If you are seeding an existing lawn, mow the grass short and loosen the top 1/4 inch of soil in bare patches. Remove debris, including dead grass. Level areas where water stands using existing soil. Fertilize bare patches.
To plant seed, spread evenly by hand in small areas. For larger areas, use a lawn spreader or a mechanical seeder. Apply about 16 seeds for every square inch of lawn. Too many seeds laid too closely can cause seeds to fight for space and nutrients. Next, cover seeds with no more than a 1/4 inch of soil. Water the lawn daily until new grass is 2 inches tall.
After preparing the lawn, use a pre-plant fertilizer over the area where the sod will go. Use 1 lb. per 100 square feet. Put down the sod starting with a long, straight line. Make sure the sod is pressed together and that seams don't match on any side. Trim sod with a knife to fill spaces or odd-shaped areas. Keep sod moist, even if it means watering before all of the pieces are laid. Roll the sod to ensure good contact with the soil. Water the sod two to three times daily for the first 10 days. Avoid walking on the sod for the first two weeks to give it time to establish roots.
Ready the lawn as you would for any perennial planting. Put plugs in the soil every 6 to 12 inches. Space them apart so they will spread and fill in. Make sure the soil is firm around the roots. Water the plugs after planting and every other day. Keep the soil moist. It should begin to fill in within a month.