Grass does not always grow the way you want it to. In some cases, soil conditions might not have been consistent throughout the yard or a disease might have contaminated an area. You might have to deal with patches of weeds as well as insects like grubs. After you take care of whatever is causing your grass-growing issues, you will need to grow the grass back in these areas.
Test the soil if the grass died for no obvious reason. Check to see what the pH is as well as the level of different nutrients. Add fertilizer to fix these levels if the test shows that they are off.
Remove objects or thin out tree branches that are creating too much shade. If the objects surrounding the lawn severely reduce air circulation, cause dark shadows or trap too much moisture, you will want to remove some of the plants or trees or remove select branches to improve air flow.
Apply a herbicide or treatment if the grass died because of some disease, mold or weed. The type of herbicide will depend on the problem you have. After the soil is treated, wait the amount of time recommended on the package before replanting seed.
Aerate the lawn with an aerator that will spike the lawn and create holes. This loosens soil and infuses it with fresh air.
Sow seed with a spreader in the areas that have died. Look at the package to confirm the amount of seed to use. If the areas are completely bare or nearly bare, sow seed based on the normal recommendations. If some grass is already in place, use the overseeding recommendations.
Sprinkle some hay over the sown areas to keep the seed in place.
Water the newly sown areas every day for the first month until new growth is doing well. Water in the morning hours. Nighttime watering sometimes results in mold issues.