Do y'all know what happens if you mow the lawn and then don't empty the grass catching bag and then it rains? And then it gets hot? And then it rains some more? Rinse and repeat about 3 times.
What you get, when you finally empty the bag, is gag inducing sludge. That's what I found when I finally got around to mowing the lawn this morning. And yes, I did empty the bag this time.