This looks really good to me. I can -I think- fully understand what you are depicting. Without covering the rest of the map in the grass lines I think you will have trouble representing what you wish (that is always an option of course but the image will look a lot busier).

And it is perfectly normal to continue in the same thread like this. Normally people will have a single Work In Progress thread, like this where they will post the progress updates etc. and then, when they think it is done, they will start a new thread in the Finished Maps section to showcase the work.