Get rid of weeds:
Weed and grass cannot co-exist. Weeds take up minerals and water required by the grass and also do not let the roots develop. They take no time in covering the entire length of your lawn. Make a weed killer solution in a bucket with water and spray it over your lawn. It will take a week to completely kill the weeds and might need a reinforcement to be completely effective. Remove the dead weed using a rake.
If you do not want to use seed killer, water the area and hand pull the weeds.The method is time consuming but an eco- friendly one.
Till the grass:
Now that you have gotten rid of the weeds, use a rototiller to till up the top surface of your soil. The tiling prepares and aerates the soil for seeding and gets rid of any remaining weed roots. Once done with tiling, level the soil. Water it now to settle the soil.
Fertilizers help in growing stronger and denser lawns. Use a fertilizer with high nitrogen content. Add fertilizer to the soil before seeding. The method of application depends on the type of fertilizer you have. Most fertilizers are granular based and you can sprinkle them over the soil surface and mix up with a rake. Refer to label instructions for specific installation procedure. It is better to fertilize in the fall because in spring, the weeds also benefit from the fertilizer and accelerate growth. You can also add compost to the soil at this stage.
To get denser grass, you will have to re-seed the grass. The best time to re-seed is when the weather starts cooling down which is early fall. Scatter grass seeds over the tilled surface. Keep the soil regularly watered to get optimum results. Water three time's a day, with breaks without making puddles. However as the grass starts growing, you can lower the amount of watering.