I have to start out with saying this was not my idea. I actually saw 2 variations of this same project on 2 different blogs but now I can't remember which.
We started out talking about landscapes. Along with that we discussed foreground, middleground, and background. I knew these terms would be "big" concepts, although when reviewing they seemed to understand. We also looked at the works of Wolf Kahn.
We then used crayons to add patches of grass, tree bark, and a few leaves. I demonstrated how to use different pressures and shades of the same color to create a bark texture. We also discussed birch trees and how they are mostly white with gray patches where the bark peels off.
Here are some results: