A lush, green lawn is a homeowner's pride and joy, but it can be a constant struggle to keep it healthy and beautiful. Unfortunately, one of the biggest obstacles to a thriving lawn is fungal diseases. Lawn fungal diseases are caused by various types of fungi that thrive in a warm, humid Southern Maryland climate. When left untreated, they can quickly spread and cause significant damage to your lawn. Applying lawn fungicide can help prevent and control these diseases, but it's essential to know when to use it.