Whipped this up as an example of how I would go about it.
I started with black as my background color and added layers on top of that.
Each lighter color starts further up.
The top half of the hedge is just the bottom half flipped upwards and lightened a bit, mostly because I'm lazy.
Notice the 'w' and 'm' shapes circled in red. Ideally things that stand out like that would need to be touched up, because they're going to stand out even more when you tile the image.
Also notice how the back edge is rigged instead of being a straight line? Ideally the sides would have the same sort of shape but I didn't bother to make the sides. As for the bottom edge you could add some tufts of color there that match your server's grass tiles so that it blends in better.