I have been given the task of looking after my girlfriend’s parents lawn while they are gone to their trailer. I had to go over a few days before they left to get the low down, because the father is very specific— but really plays it down. Wants the grass bagged on the front and it has to be on a specific angle and done every 4 days or so…always in the morning, never the evening. He is particular. Which is fine. I did my first cut a few days ago, lawn looked spectacular…for the most part. I noticed a few black patches had appeared. Were they there before? No idea. Did I cause them? I hope not. What are they? What do I do to fix it? and did my girlfriend’s father who is meticulous with his lawn, know about this problem before and not tell me? Is this a test?