Ok, so the next question I have is regarding the speed of growth. I have blackjack seeded in the back and some form of tif sod in the front. I had mowed Friday morning before we left to visit some family and when I came home Tuesday my back grass already desperately needed mowing, so I mowed. The front was fine. Wednesday it was already looking ragged again, Thursday you could tell it needed mowing already and today I just couldn't stand it any longer and mowed it again. I mowed the front, but it definitely didn't need it as much as the back. Now, I mow at 1.5 inches because I'm trying to outcompete some weeds, and my soil isn't 100% even. I seeded the back this spring and the front got sodded this spring since this was a new build. I recently put out 15-5-20 front and back. It's been raining a bit. But is this normal for blackjack to grow at such a rate? I thought this was supposed to be a slower growing grass. I'm having a hard time keeping up.

My first guess at the problem you have in the corner is lack of deep water leading to just a slight increased susceptibility to chinch bug. Chinch bug almost always strikes at the edges of warm concrete. Notice how only the edge is being attacked along the sidewalk. For more on what chinch bugs look like, check YouTube. There are some very good images of them. How often do you water and for how long? What kind of sprinklers do you have?

Surely they do! Well, not that I'm aware of. Anything that you can spray on one species of plant will almost always kill all varieties of the same species. The TIF mutation is different from common, as you are well aware, but not enough that there are targeted herbicides for one or the other. The tough love approach is to spray it out with RoundUp and replace the dead area with a new piece of Tif 419. If I were going to do that I would measure the size of the piece of new Tif and make a template out of cardboard. I'd spray the area inside the template, let it die, cut it out, and drop the new sod. So if the new piece of sod was 24x36 inches, cut a 24x36 inch hole in a box and use that to protect the surrounding grass from over spray. Remove the box and watch the magic happen. In a couple days you can cut out the old and replace with the new. Be sure to prep the bare soil to make it level before putting the sod down. After you think it's level, walk on it to press down any fluffy spots. Re-level as necessary. Then drop the sod and walk on that again to ensure good sod-to-soil contact. Roots will not grow through the air to reach the soil. When you water the new sod, all you have to do is keep the sod moist. You don't have to saturate the soil underneath.

I don't know where you live, but the UC Verde buffalo grass planted at the REC in Irvine is still brown because of the very cold nights we had at the end of February. No low water use plant uses less water until it is established. That takes at least a year. It's after that you will be able to cut back on watering. Bermuda is pretty stubborn, but I have been able to manage it by manually pulling it from my landscape. It is not blended in with other grass, however, just shrubs and trees. I don't see how putting in a hybrid bermuda will solve the problem. I have Tifgreen in my back yard that was put in by the original owners many years ago. A few years ago common bermuda was introduced (probably when I had a lawn service) and it tends to crowd out the Tifgreen.