To grow a lawn from seed requires both physical labor and timing. Grass needs approximately two months from first planting to when it is able to withstand mowing. To grow a lawn from seed, begin the process in the early spring or fall so that the grass has the proper climate and time to establish itself before the heat or cold sets in.
Prepare the area. Turn the soil with the rototiller so that it is loose enough that you can break apart the soil in your hand. Work to a depth of at least six inches to eliminate any unwanted roots or hard ground that can affect the roots of the grass you'll be planting. This will also allow the soil to absorb more moisture at a deeper level.
Fertilize the soil. Use fertilizer specifically designed for grass, which can be purchased at garden stores. Follow the directions on the packaging in order to load your fertilizer spreader with the appropriate amount of fertilizer. Operate the spreader over the area in a north-to-south direction. Repeat in an east-to-west direction so that the fertilizer is evenly spread.
Spread the seeds. Load the spreader with an average of four pounds of grass seed per 1,000 square feet. As you did with the fertilizer, operate the spreader in a north-to-south direction, and then repeat in a east-to-west direction.
Fill a cage roller with fine, organic mulch. Peat moss or ground bark work well. Operate the roller quickly over the area in the same crisscross pattern you used to spread the fertilizer and seed. This will create up to a quarter-inch of covering to protect the seeds from drying out.
Maintain a watering schedule and pattern. Water the ground with a lawn sprinkler until the first six inches of soil is damp, which you can gauge by driving a hand spade into the dirt and then pulling it out. The spade should have soil sticking to it from tip to handle; if it doesn't, the soil needs additional watering. Water the area whenever you notice the area is drying out, typically weekly. Sprouts will begin to show after about four weeks. From this point forward, water the area less often, but maintain the six-inch guideline, which will require that you use more water. Follow this watering regimen until you begin mowing the grass.
Let the grass reach a height of three inches before the first mowing. This will allow the roots of the grass to gain a permanent hold to the soil. Cutting tends to put stress on the grass, and mowing can kill a lawn if it is done too soon or too often. It's advisable to mow once per week, or perhaps twice if a heavy rain causes the grass to grow faster in a given week. If you plant the seeds in the fall, reduce the mowing to bi-weekly because the grass is readying for a hibernation period.