I personally think you did a pretty good job, myself. I think it might work out better to try and make a proper texture out of that grass, then to tile it across the area deleted, but that does require proper tools. However, the grass might look okay even if you just copied and pasted it; I don't think seams would show up easily. If you like, I'll take a look at it tonight; I'm off to work in an hour and a half, or so.