Your climate should be the first factor considered when choosing a grass seed type. Grass comes in two varieties: creeping or bunching, which describes how the grass grows. Creeping grasses are designed for warmer climates, while a bunching grass, or a mixture of bunching and creeping, is best for northern climates. Planting grass seeds in the cooler temperatures of fall or spring will avoid sun-scorching of your new, tender grass.
Seeding a Full Lawn
Assess expected foot traffic on your lawn. Choose hearty, broadleaf grasses for high foot traffic and fine leaf for low traffic and a more luxurious-looking lawn.
Research your area's growing conditions. Select a grass type that is rated for your planting zone and the amount of sun your lawn will receive daily.
Calculate your lawn's area in square yards. Purchase 1 ½ ounces of grass seed per square yard of lawn.
Loosen your lawn's soil. Use a cultivator or similar garden tool to loosen the top 2 to 3 inches of soil in preparation of sowing the grass seed.
Level your lawn. Use a rake to smooth your soil and remove any unwanted debris, such as stones and large sticks.
Put the grass seed into the broadcast spreader and set it to sow 16 seeds per square inch. Run it, at a steady pace, over the entire lawn.
Cover the newly sown seeds with ¼ inch of fresh topsoil and water the entire lawn well. Use a sprinkle setting to moisten the soil without drowning the new seeds. Water your new lawn regularly.
Seeding in an Existing Lawn
Prepare the sparse areas in your lawn by loosening the soil 1 inch deep with a cultivator or similar tool.
Fertilize the sparse areas with a liquid fertilizer.
Sprinkle the grass seed on the sparse areas by hand, evenly but lightly.
Water the areas lightly; just enough to moisten the soil without drowning the new seeds. Water the newly planted areas frequently to promote growth of the seed.