Lawns develop dry, thatched patches due to frozen snow or ice, heavy foot traffic, salt burn, pets or pests. To ensure a new coat of even grass, rake your lawn to remove the thatches and re-seed to fill in holes. Early spring or early fall are the best times of the year to rake your lawn. In the spring, your lawn begins to grow again after winter dormancy so you can tell which areas need to be raked and which are healthy. In the fall you can rake your lawn as part of seasonal cleanup.
Loosen thatches and matted areas by gently raking with a metal rake. Drag the rake through the thatched grass, then stop when you reach the end of the clump. Repeat this process as if you were brushing a tangle of long hair. The thatch will loosen with repeated attention.
Switch directions, raking, for example, east-west instead of north-south. Changing the direction helps unmat the thatched grass without tearing out too much turf.
Collect the dead grass you've uncovered when raking. This dead grass will be tan. You can compost this grass or dispose of it with your yard waste.
Rake all thatched areas of grass in this manner. Dispose of all dead grass.
Water your lawn after raking until the lawn becomes moist but not wet.