The answer to 'weed control not growing' is that there are several common causes, including poor soil quality, improper application, and competition from other plants. Symptoms may include sparse, unhealthy weed growth or no growth at all. Solutions can include improving soil nutrients, reapplying weed control products correctly, and managing surrounding vegetation.
If weed control issues persist or you're unsure of the cause, it's best to consult a professional landscaper. They can diagnose the problem and recommend the most effective treatment options for your specific situation.