Yes, this is a system used by "vertical" gardeners. I believe you will need some kind of drip irrigation, though... Hard to keep them from drying out. Give it a try and keep us posted!
One, used fairly large diameter pvc pipe with sections cut out. They grew strawberries!
The other, used gutters for potted hanging plants. As long as the soil was light weight, it worked well -- the gutters were attached to a board wall. Watering was handled by starting the water at the top and allowing it to run thru several sections of gutter as it descended the wall.
Not anywhere near this steep but I've only got the back and forward slashes :/ . . . maybe you will get the idea:
Can't do drip irrigation this year, but may be next. Any other space saving ideas? I would make a garden box and hang on the fence posts, but it would be too heavy. I could make a shelf on the fence and put pots, but they might blow over. What about grow bags. What do ya'll use if you can't buy them?
What about placing sponges on the very bottom of the gutter before you put the dirt and plants in? Could they hold and release water? Has anybody ever tried this? I Ask because I've been given planting kits with sponge type potting soil. You're supposed to put the seeds on them--that never worked well, but I've thought about putting one at the bottom of a pot to see if it would keep the soil from drying out.
So Steve, you say that just water it with a garden hose like I do every thing else. I don't need a special drip system? That I can do. I'm already watering my SFG everyday, I can turn 180 degrees and water the gutter. Do I need holes in the bottom for drainage?
Hangin', they just allowed the water to drain from 1 gutter section to the other. The angle of the gutters was very slight so the water moved thru them slowly and each potted plant was watered as the water descended thru about 4 sections on the wall - one above another.
It has been quite a few years since I came across this but it seemed like a sensible way for greenhouses to keep hanging indoor plants. Probably could be applied outdoors just fine . . . (altho' things aren't working out too well for me outdoors or in, today - totally unrelated issue.)