I see that! Nicely done, @doctorspence. When I made my plant box, I used pond liner / rubber to line the inside and keep water in and light out. 😉 I also disassemble pallet wood and use the pieces, like in the plant tables in the post. They were made from pallets I used a sawzall to dismantle. It takes a great deal of time to do, so maybe a roll of pond liner will be easier for your plant boxes.