I agree with DeLong about getting it its own space, but I think you need to be careful not to take that too far. The first concern is that it appears that under certain circumstances the gatherings exceed the area of the pavement so you don't want to enclose it. The second concern is that it is in the context of a very big open field and needs to work in "the big picture.
I like the idea of a backdrop like DL said, but I suggest that it is a straight hedge parallel with the straight edge behind the cross and parallel with the road and existing trees. I would not put it against the pavement, but back halfaw to the oaks. I'd also keep it lower so that you can see over it and so that people on the street can see over it as well. Have it extend past the edges of the patio by half the width of the patio (ie, if the patio is 30' wide, the hedge would be 60' long). Even though you would be able to see the buildings in the background, it will make them not noticed. You could then dress up the front of the hedge for the width of the patio with more colorful plants, if you want to. I'd keep an apron of grass in between, though.
The bigger the landscape, the more simple you should keep it because the details get lost.