Answer: Based on your description I am not certain what is causing the brown or bare spots. Usually, you can patch a spot in a lawn by removing the dead grass, loosening the soil down about six inches, working in some compost, then raking smooth and placing sod or spreading seed. Cover the seed with a little loose straw in a thin layer to help shade the ground. Keep it evenly moist until it germinates (or until the sod becomes rooted in place).
If the grass dies out repeatedly, there may be some unseed cause such as an underground rock that makes the spot very dry, an old chemical spill such as fertilizer that has damaged the soil, or tree roots that steal moisture and nutrients from the soil, or something like that. I would suggest you also consult with your local county extension to see if they can help you troubleshoot. Good luck with those spots!
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