I have a nasty infestation of nutsedge in a landscape bed, probably because I didn't know to completely remove all of the soil 5' down and replace with non-infested soil before I started planting. I have herbs in the bed, rosemary & basil. Does anyone know of a way to kill the nutsedge without killing my plants? I've read that dry molasses will get rid of it, I guess by improving the soil? Would it truly be as simple as amending the area? Or should I just give up and call it "monkey grass"?