Sometimes soil isn't even needed to plant anything; hydroponic technology allows for plants to grow along the walls of buildings without bringing harm to a building's infrastructure. The idea is to bring water to the plants before their roots grow in search of water and penetrate the walls of the structure they're growing on. A hydroponically or aquaponically based vertical garden may function the same way a fish tank's water is filtered and recirculates. Growing plants on the walls of a building also has insulation properties, not to mention it can also act as rain screening. Seems so simple, right?
There are also smaller scale, and non-hydroponic vertical gardens that can be planted. For example, there are plenty of blogs that talk about using old shoe organizers to grow herb gardens in, or even old rain boots might do the trick too.
Better Farm, we're working on installing a couple of vertical gardens of our own! We have been using a handful of stacked and rescued tires to grow our potato plants in the garden outside, and we're working on having an accessible herb garden in the kitchen for this winter.