Growing new grass is all about site preparation. Without the proper amendments and attention, grass seed will not germinate and you will not achieve the desired result. Plan to prepare the soil and plant grass the same day or in a two-day period. It's essential to tackle the project in dry weather; rain will wash away grass seed and make your task more difficult. Grow new grass in the spring or summer so it has time to root before winter sets in.
Prepare the planting area by removing rocks, sticks, weeds and other debris. Break up clumps of soil that are larger than 1 inch in diameter.
Run a rototiller over the planting site until you loosen up the top 4 to 6 inches of soil. Grass seed will root much better if it can easily move through the soil.
Shovel topsoil onto low-lying areas and dips. Leveling off the area will prevent water from pooling. Mix the topsoil into the local soil so the roots penetrate both. Rake until smooth and level.
Spread sand and compost on top of the soil to improve drainage and add nutrients. Add 1 inch of each and mix it in thoroughly with the rototiller.
Apply a seed starter fertilizer or one high in phosphorus to enrich the soil. Use a broadcast spreader to apply it. Set the machine to the rate indicated on the fertilizer label.
Disperse grass seed evenly with a hand spreader if you're working in a small area. To grow new grass in a large area, use a mechanical spreader.
Gently mix the seed into the top of the enriched soil with the back of a metal rake.
Water the new grass with a sprinkler set to the oscillating setting. For the first 10 days, run the water five to 10 minutes twice or three times daily. When you notice the seed is sprouting, cut back to watering once a day for 15 to 30 minutes.