Lots of bad attempts at material mix, but the staging is taking form…
I understand what you are tying to do. But if you render grass (which takes a lot of time, as we all know), you don’t see the floor. Working with projects like these, you need to have a plan and follow it. You can loose a lot of time on details which aren’t seen or needed.
But I know the feeling … the urge to create 
and try It’s addictive …
I like the scene with al the bright colours very much. I hope to see the final version. Happy rendering.