need help with collision

Hey guys I need help with collision.

Do you guys remember that tutorial on this site where you create a panda moving around in that environment with grass trees and rocks. Well im wondering is there a way to make it so that when I move an object into the grass trees or rocks or anything visible, a collision would occur not allowing me to move through those things? I know that I can add collision solids to every location of the grass trees or rocks but that seems very tedious.

[A Minimal Collision-setup)