I have a north-facing balcony on my apartment. I would like to turn a 10' by 4'7" section into a small garden. So far I'm planning on growing tomatoes (possibly hanging), yellow, green or scarlet runner beans (the latter was suggested by a coworker to add colour, might grow a mix of all 3), Herby cucumbers (or some other small variety, it'll be for pickles) and lettuce. I'm open to other suggestions too, even non-food things, especially if they are beneficial to the garden.
My balcony is covered, so I'm thinking of hanging an eavestrough of some sort along the outside of the railing, possibly along the full ~20', to collect rainwater, which will be used for the automated watering system.
I am going to build some elevated planters with drains for excess water, not that there should be much once the system is running well. I plan to automate the watering with a Pi, some humidity sensors and an Arduino if necessary.