I thought I’d give this a try, because I love the idea, although unproven. Last year my tomato planted upside down in a juice jug was a total fail, probably not least because of the transparent jug, and inadequate gasket around the stem of the plant. This time I roughly copied the technique of a guy I met hitchhiking (cute, and he gardens!), and the summer will tell if it’s a success. Both of us saw this in the Lee Valley catalog, and although the special pots they sell are certain to be sophisticated technology, there has to be a way to make them work low-tech.
First things first! Drive the nails or hooks where you’re going to hang them. Because the moment you have one full, you’re gonna need to put it somewhere to get it out of your way.
2011 edit: Once the ball is through, then put the two square slotted pieces (in my hand in this pic) around the stem under the root ball as shown in the second photo, above, and you can snug them up tight and make sure they’re flat. Then add a little soil and water the surprised root ball.
View from inside the pot. The root ball and its two collaring plastic pieces have been pushed into the pot and through the poly piece covering the whole bottom of the pot, where the small pieces are smoothed out flat. The root ball is quite smushed and battered. The plastic around the stem of the plant is tight.
I hung these three experiments from the eave and watered them. They look to me a little surprised to be inverted, like upside down question marks.