How to kill the grass

OK, here's the scenario. I have a fairly large flat plane with a particle system of grass covering it. On a regular basis, I will be reusing this grassy plane in different scenes and overlaying it with plants and mulch beds (odd shaped planes slightly above the plane of grass). I need to make it so that the grass (hair) particles do not go through the plant or mulch bed meshes. I am trying to make it work with Collision settings but so far, having no luck. I have seen mentions of Deflector objects and "killing the particles" but can't figure out how to make those work. I don't want to have to deal with weight painting the areas where the grass would intersect with these other mesh objects. I just want to make it so the grass does not pass through them. There must be a way of doing this.

My scenes are not going to be animated. They are just for a single rendered frame. Any help would be greatly appreciated.