Concrete to Grass Transition

I'm using these as a transition between the concrete sidewalk and the grass. I use a rubber mallet to gently pound them in after I get the grass a little wet. I always have a build up of dirt along the transition point between the concrete and grass and my trimmer will only go so far. Hope this helps some of you with the same issues I've been having. Looking to mix up the colors as I move along, although Gold is still my favorite.