As we moved into a different space at work I saw this concept in action and saw how giant part crates could house tropical plants...
The parts bin was lined with plywood and an adhesive self healing paper (used for sealing around windows) was applied to the lower half to protect the wood from any water damage.
The bin is very large so several plants were used inside each. Plants are potted individually and sheets of styrofoam were added inbetween each pot. Pots were put in very close and were covered with moss to hide the styrofoam. On top of the moss large river rocks were added.
When watering the plant, it is only watered at the base of each plant to make sure the water gets into the pot and not the spaces in between (although if it spills the container is protected!).
I haven't tryed this yet myself at home, as my house is quite small but I'm keeping my eyes out for anything that could give this similar look.