We have shown you what a hydroponic system is. It is basically a system that uses nutrient rich water solution rather than soil to grow plants. Another beauty of these types of system is that they are easy to DIY and you can stack them up for a tall vertical garden.
This DIY system from Greenerways2012 shows how to grow 168 plants in an easy to make and portable frame with mostly PVC pipe and lumber. What do you think? I would probably paint the pipes green or use green pipes.