Do I need to kill and/or remove existing weeds and turf before sodding or plugging?
Not necessarily. If the area is not level, it would be best to level the area, that is, fill in the low spots and take off the high spots. You can use an herbicide such as Round-up to kill the existing turf and weeds about a week prior to plugging or sodding if you like. Some folks prefer to remove the existing plants with a tiller or sod cutter.
