I have my veggie garden (2 strips of land about 4' X 15' and 2' X 13' or so) and love the idea of raising it up about 3 feet. Is there any way to convert it to this height and what material would be used to create the "box"? My hubby is an engineer and can construct almost anything. I organic garden so don't want to use old railroad ties or treated lumber. Any ideas? I also love the idea of vertical gardening and looked at those sheets of pockets you can hang. They seemed very expensive. Can a person make them and what material would be used? Thanks, all you creative thinkers!