Have grown upside down before, but the containers were small decorative things. Sure you know the type, bowl shaped lined with burlap. Most turned out small and I had to water them every day. Thinking on building a second high tunnel. Looking at the first, the center is maybe 8 foot high. Plants are maybe 4 foot high. Seems like there is a bunch of space not being used. Kind of wondering if I were to use five gallon buckets up there and painted them black if i wouldnt get more growing space and create a row of heat sinks. Hmmm.... Thought about building wood boxes into the thing but if it restricts too much light, i want to be able to remove them.