Just an experiment using clip files of fake stone shaders. I left the large tree on the left to hide the horrible cliff face. (This did not work out at all)
http://www.flickr.com/photos/njeneb/5369483955/sizes/o/in/photostream/
i think the fake stones look pretty good actually.
It's not the stones, it's the hillside behind the tree. Bad Hillside! I made the fake stones separately and imported the clip. I was almost pleased with them. The medium size stones got botched up. I was in a hurry to get to work. I made the spike level too high.