i love this idea for your arch! just buy two really old doors and then connect them with a piece of plywood so it will stand and then cover the wood with flowers. Then the doors could decorate the home afterwards.
3 old doors hinged together makes a unique ROOM DIVIDER. With a chandelier hanging above, makes a pretty vignette for a store display. Could be a photo prop background for vintage wedding or used for a trade show or craft booth display.