Make a Gutter Garden

I wanted a raised planting bed garden this year. Is it going to happen? Me thinks not (basement reno comes first)...but that doesn't mean I have to sacrifice growing my own lettuce in the meantime. I was thinking of dressing up one exterior wall of our garage with shallow planters. The garage wall isn't precious (ie. if I wreck it a bit it's not big deal)... This Gutter Garden is something I could attach to the wall (right now I have don't have a place to hang it but I do like the idea of hanging a garden)...from here.