To plant grass seeds in dirt, you need to take into account the nature of the dirt. It's highly compacted, which means there aren't many air pockets under the surface. Air pockets are present in loose soil. These pockets give the roots room to spread. Dirt also lacks many nutrients necessary for creating a lush, manicured lawn. With proper site preparation, however, you can make dirt conducive to growing grass seed. Set aside a weekend to do the project--one that is forecast to be rain-free.
Remove debris such as weeds and rocks from the planting area. If there are any dirt clumps larger than 1 inch in diameter, break them up. If there are a lot of weeds, kill them with a herbicide. Apply it a few weeks in advance to avoid trouble once you plant the seed.
Loosen the top 4 to 6 inches of dirt. Run a rototiller back and forth over it. Spread topsoil in low-lying areas to level the yard. Rake until smooth.
Make the dirt fertile. Spread an inch each of sand and compost to the dirt to improve nutrients and drainage. Combine both into the top inch of dirt.
Apply a starter-seed fertilizer to the yard. Set the broadcast spreader to the rate indicated on the package.
Spread grass seed with a hand or mechanical spreader. Use whichever method works better with the size of your yard. Use the back of a metal rake to cover the grass seed with a small amount of the amended dirt.
Water the grass seed at least twice a day for five- to 10-minute intervals. Do this for 10 days. Once the grass sprouts, reduce watering to 15 to 30 minutes daily.