This is an effective and amazing solution if you have limited space for gardening. In this Youtube video, John explains how to use the Garden Tower Vertical Container Garden to grow 50+ plants in just 4 square feet of space. This is an interesting system that lets you put a veggie garden on your patio, balcony, sidewalk, deck, small garden, or parkway. It uses soil and also has a built-in composting mechanism.
John is an avid gardener and is very enthusiastic about the garden tower approach. He goes into a lot of detail about his preferred soil mixture. It really is a very thorough video and review.
You can see a terracotta version here: The Garden Tower- The Composting 50 Plant Organic Container Garden
Click on the Garden Tower Vertical Container Garden link below to see the video.