If you liked the self-watering tomato container we shared with you but you're very tight for space, you'll want to take a peak at this hanging, self-watering planter, perfect for balcony-grown tomatoes.
Instructables user velvel had all sorts of methods to try out for a low-waste balcony garden. Self-water pots, upside-down planters, drip irrigation—all led to more waste than was necessary. The trouble with seemingly simple drip irrigation is described in detail:
I suspended a tank of water above the level of the top of the upside-down planters and ran a thin hose across the tops of the planters with drip nozzles. The problem was that I could never get the water balanced so the first planter would get the same amount of water as the last. I also had problems getting them to drip slowly enough to last all day. Most of the time, I would be able to keep them hydrated but there was a lot of waste as the the water would run through the plants after an hour or less. Going away for the weekend meant severe drought damage.
The current version of velvel's hanging planters wicks water through a series of hoses right into the planters themselves and, unlike prior attempts at self-watering planters, there is no waste water running off or premature drying of the soil. The project is definitely for the detail-oriented, but the parts are readily available in the plumbing aisle of your local hardware store. Check out the link below for the full tutorial. Thanks Daniel!
Upside-Down Hanging Earth Box [Instructables]