Hey, not a great picture but a great idea we got from the Centre of Alternative Technology. Basically you build a spiral of earth using upturned bottles, wood, bricks, whatever as the walls. Wet herbs go at the bottom (you can even have a little pond with mints, watercress etc around / in it), dry herbs go on the top like rosemary etc and others go in appropriate places around accordingly as to how much drainage, sun etc it needs. It’s very space saving, cosmic-ly spiral and would be great in schools.
Get the tip sheet on it here for 50p