I recently moved into a new home and this is the first summer taking care of the lawn. I'm relatively inexperienced when it comes to lawn care. I've been getting these large areas of grass die off thru out the summer. They started pretty small but as you can see, have grown pretty large. I don't think this is the typical summer browning but am not sure what is causing it. Any thoughts? Grubs? Fungus/disease? Over fertilization?