It came out rather good? Didn't it? I would try to get, like, the grass to have one color over the whole picture. Maybe by making a selection and replacing the color, or by recreating the grass based on one particular piece. But that would be trial and error. Adjustment layers with mask might work. The main point always should be if people who don't know would, well, have a clue that stitching has been practised. In this case, most of the people who enjoyed the prank will look at it as a sufficient recording of the event. And not see the photoshopping.