The answer to 'shrub turning brown' is that there are several common causes, including drought stress, disease, pests, or nutrient deficiencies. Symptoms may include leaves turning yellow or brown, wilting, or dieback of branches. Solutions depend on the underlying cause and may involve adjusting watering, applying fertilizer, treating pests or diseases, or replacing the shrub if it's beyond saving.
In many cases, the cause can be diagnosed and addressed through DIY methods. However, if the issue persists or you're unsure of the cause, it's best to consult a professional landscaper or horticulturist who can properly diagnose and treat the problem.