Need some advice here. I have El Toro front and back. In part of my backyard (~300 sq feet), it is very protected from sun both by trees and privacy fence. Some of my El Toro sod died off, which was also aided by my dogs running along the fence. This is a section about 30 feet by 6 feet, and then there is another four feet or so that is sparse. Last year, rather than trying to track down sprigs or sod to resod that area, I went with a Scotts shade seed mix. It apparently had some tall fescue in it, and while it did not take in the part that was completely bare, it is growing in the areas that were sparse, mostly growing in clumps. That's the background, now the questions. First, should I leave the tall fescue to fill in where my El Toro was weak and then just let the strongest survive? Second, and related to the first, is it likely that the tall fescue will invade into the main part of my back yard and choke out the El Toro where there isn't a shade problem. My original thought when I threw the grass seed down was to just go with whichever grass survived, but I assumed that it would be the El Toro, which holds up very well to my dogs running, once it is established. So, I am wondering if I should hit the clumps with roundup, trying to lose as little of the El Toro surrounding them. Or, to let nature take it's course. I guess it sort of bugs me to see Tall Fescue listed as a grassy weed and then see it in my backyard. Kind of like I am not doing my job right.