The answer to 'mulch dying plants' is that there are several common causes, including improper mulching, excessive moisture, pests, or underlying plant health issues. Symptoms may include wilting, discoloration, or stunted growth. The solutions can vary depending on the specific cause, but may involve adjusting mulch depth, improving drainage, treating pests, or addressing root problems.
In general, it's best to start with basic DIY troubleshooting and maintenance, but if the issue persists or you're unsure of the cause, it's recommended to call in a professional landscaper or horticulturist. They can properly diagnose the problem and recommend the right treatment to revive your plants.