About 5 years ago, I installed my lawn, seeding with Lesco Premium Fairway & Athletic mixture (Lesco Item 056497). I do not know the exact makeup, but I believe that the mixture contains a high % of Kentucky Bluegrass (2 varieties), and what looks like "Legacy II Perrenial Ryegrass". All was well the first and second years. The third year, I covered the rip rap in the drainage ditch alongside the road with a non-woven filter fabric, then loam from a known source, and then some of the leftover seed. I later noticed that the grass in that area was light green (as opposed to darker green, with the bluegrass), the blades were finer, and the growth more dense. The different color/texture was irritating, but did not rise to the top of the list. Over the last 2-3 years however, that patch has spread, and I have now noticed small patches of that lighter, finer and denser turf scattered about my lawn. Any thoughts on what I did wrong, and how to fix it?