This was still too detailed and fussy however, so I decided to try creating a flat, impressionistic grass texture.
I think this sort of texture looks effect without being too detailed. I am not happy with the plain silhouettes though, so I tried adding some planes with alpha channels to roughen them up a bit.
The idea was good but I could not get it to work as the planes and ground always looked like separate objects. I knew that Toon Shader could create a line around the profile of an object and I tried attaching a file with an alpha channel to it. Unfortunately I had a lot of problems, the main reason because the outline it gives is actually three dimensional geometry and I was unsuccessful in my attempts to convert this into a two dimensional plane. It was also difficult to map the texture to the geometry.
I went back to using planes with alpha channels and played with various textures. I am happiest with the one pictured below and will base the final texture of this design.
