Not surprisingly, the tougher the growing environment, the tougher it is on the turf. Due to the growth of vegetation over the years, the right half of #18 green is "pocketed." There is little air movement, and no morning sunlight.
Patches of stressed turf aren't usually something to be proud of. However, this is more about what is healthy than what is not. When people ask why we have to aerify, hopefully this picture tells the hole...uh, whole story.
|Aerification holes make a clear difference in this patch of turf|