I installed a new row, this time with two pairs of screws in drywall, and outfitted them with orchids from a friend's personal collection and rescued from other friends.
Most Americans I know have trouble keeping orchids in bloom. This is part personality mismatch, part misinformation, and part poor commercial design. One of the orchids was seated in the typical plastic root cup inside a sealed pot full of extra mulch and moss. There was an inch of stagnant water at the bottom when I got it. No wonder it had lost its flower spikes and the leaves were starting to turn!
I think orchids will be perfect for pocket gardens because they require the occasional minute-soak, drain quickly, and spread over vertical surfaces.