The answer to 'hedge turning brown' is that there are several common causes, including disease, pests, drought stress, or improper pruning. Symptoms may include discolored, wilting, or dead foliage on part or all of the hedge. Solutions can vary depending on the underlying issue, but may involve pruning, treating pests or diseases, or improving growing conditions.
If the hedge is only slightly affected, homeowners may be able to diagnose and treat the problem themselves. However, for more severe or persistent issues, it's best to consult a professional landscaper or arborist who can properly identify the cause and recommend the appropriate treatment.