I tried this last year with little success, but I think I know exactly what I did wrong.

I used 1/2 gallon milk jugs, and these let TOO much light into the root area. Walmart is now selling their own version of the Upsy Tomatoes ($7 here), and I thoroughly examined their set up. Sure enough, that and every other I've looked at online are pretty solid, not letting much if any light get to the roots.

I plan to repeat the experiment again this year, but will shield the roots from any potential sunshine. Haven't decided if I will paint the outside or newspaper the inside.

jane b