We came upon this picture of a London greenhouse made out of discarded plastic water bottles. It’s part of a thriving rooftop farming project run by Food From the Sky. We get to see a lot of funky greenhouse designs from discarded materials, and many are visually interesting but don’t seem very practical. But, this design looks to be more than a grad student’s thesis project. It looks practical and productive, and judging from the abundant container garden around it, the Food from the Sky team knows its stuff. Maybe we’ll borrow this idea for One Acre Eden. You can see more pictures here.