The answer to 'mulch dying' is that there are several common causes, including improper application, lack of replenishment, and environmental factors. Symptoms include the mulch becoming thin, discolored, or breaking down too quickly. The best solutions depend on the underlying cause, but often involve adding fresh mulch, adjusting application depth, or addressing issues like poor drainage or soil pH.
If the mulch is dying due to a specific problem like pest infestation or disease, it's usually best to call in a professional landscaper to diagnose and treat the issue. However, for general maintenance and replenishment, homeowners can often handle this task themselves.