Hi, I have a large lawn that looks like a golf course in the spring! Full, lush grass needing to be cut twice a week. I usually notice that the grass "changes" come summer. I thought it was usually due to higher temperatures and less rain (although I do have an irrigation system). Since we've had a relatively cool and wet spring here in the mid-Atlantic area, the grass has been doing quite well. What I have noticed though, and recall this from years past is that the grass appears to become less robust, and tends to lie down and form mats. The underlying grass tends to brown and die. Mowing does not seem to be sufficient enough to pull up this grass. Is this a natural process? Does it have to do with my type of grass? I have a friend who has a lush yard and I don't notice this taking place in his yard. His grass continues to grow tall...although it does slow down.