The answer to 'landscape design turning brown' is that there are several common causes, including drought, disease, pests, and improper maintenance. The symptoms can include wilting, discoloration, and patchy or uneven growth. Solutions may involve adjusting watering, treating diseases or pests, or making changes to the landscape design and plant selection.
If the issue is widespread or you're unsure of the cause, it's best to consult a professional landscaper. They can diagnose the problem and recommend the appropriate treatment or redesign to restore a healthy, vibrant landscape.