Planting a lawn requires evaluation of your existing soil and planning for a successful crop of grass. Grass functions in a very similar manner to a plant. Seeds become baby plants that have specific requirements in order to growth. Planting new grass seed begins with the quality of the soil. The success of your crop depends on the amount of topsoil covering your yard. You can plant new grass seed for an entire lawn and to improve bald patches.
Seeding a Lawn
Evaluate the depth of the current topsoil in your yard. Topsoil forms the perfect foundation for grass seedlings, but the depth must be adequate to nurture adult grass roots. Aim for 10 or more inches of topsoil application for the best success.
Apply the topsoil to the entire yard surface and spread it evenly using the rake and shovel. Many homeowners have the topsoil trucked in and dumped on their lawn in large quantities. Amending the soil before seeding offers the grass the best opportunity to thrive for a long time. In contrast, adding topsoil to small sections of the lawn doesn't provide a uniform planting surface, nor does applying too thin of a topsoil layer. Aim to provide the best possible base for your grass seeds.
Set up and turn on the sprinkler to prepare the ground for seed planting. Run the sprinkler to moisten the soil and then allow the topsoil to dry. Puddles will occur in low spots. Locate these uneven areas and level with a rake. Wait two days and perform this step again. Water must be able to percolate down into the soil for the health of future grass roots. Of course, alter this watering schedule if it rains. Seeds require moisture in the soil for germination. Cycling of absorption of water into the soil will encourage uniform moisture levels in the topsoil.
Grade the entire lawn with a rake for uniformity. You'll be planting your seeds directly onto this surface so level the topsoil and make sure it slopes away from the house.
Apply seeds based on the package recommendations by variety of grass. See additional resources for information on planting density from Purdue University's Turfgrass Science Program.
Cover planted grass seed with 1/8 to 1/4 inch of topsoil. This level should be exact to encourage soil and seed contact and good germination. Planting too deeply can cause seed failure. This topsoil layer offers great protection from animals and weather to keep the seeds in place.
Water lightly and frequently to maintain moisture levels throughout the topsoil. Avoid heavy watering because this can cause shifting of the seeds.
Seeding Bare Patches
Rake the area to stir up existing thatch (dead grass) for removal. Get to the soil and gauge the moisture level. Planting patches work the same as an entire lawn. Topsoil should be moist and loosened to accommodate seed germination.
Water the area to encourage slow moisture retention in the soil. Do this in stages over a few days to encourage slow percolation to a depth of at least 4 or more inches. Stick a trowel into the lawn to gauge moisture depth.
Spread a 1-inch layer of topsoil in the bare patch. Water the soil and allow it to dry slightly. Do not plant on soggy topsoil or lawn bald patches.
Spread a layer of appropriate grass seeds in the bald patch and cover with a 1/8 to 1/4 layer of topsoil.
Water regularly to keep soil evenly moist.