The answer to 'weed control bare spots' is to identify and address the underlying causes of the bare spots, then overseed and establish healthy grass. Common causes include drought, poor soil, excessive foot traffic, or pest damage. Symptoms include thinning or dead grass, exposed soil, and weed growth.
To fix bare spots, start by aerating the soil to improve drainage and oxygen flow. Then apply a balanced lawn fertilizer and overseed the area with a grass type suited to your climate. Water regularly to establish the new grass. If the problem persists, the soil may need amending or the area may require resodding by a professional landscaper.