There are basically two ways we install a timber border without using concrete. First, using 4" x 6" or 6" x 8" treated timbers, you can stack, straddle joints and install using rebar anchors so they don't move. Alternatively, a typical post and plank wall system can be built using 4" x 4" or 6" x 6" with a 2" x 12" plank with cap as shown in the picture on the left. These borders work fine, but lack the “official” system of mounted boards.