Here is one example. The first image is the regular wall texture, and the second image is one of several variations of it.
It's not quite as simple as just placing some images on top of another. Color balancing and shadow effects are added as well, and the brick pattern is adjusted. At this point I'm not sure how many variations will exist, it depends on how many I can realistically create (I'm going to run out of plant and brick pattern variations). Either way this route is much more performance friendly than having actual meshes for the plants and what not, but the in-game wall will offer both, especially near the lower part of the wall, where infantry can walk.
But yeah, work continues.