Lawn is in its 3rd year and has some bare spots primarily due to some concrete work done last fall and a few dog spots. I was just wondering why most of my lawn is pretty consistent except for a few patches of the real dark thick green stuff. What should I do? BTW, I realize the yellow spots are dog marks, but the real thick dark green stuff doesn't coincide being around the dog spots. The dog is now taking treats to neutralize the ammonia and not burn the grass. Works pretty well.