A balcony rustic can be as complicated or simple as you want. You can spend thousands of dollars or you can do it for very little money. With plant and container choices you can either make a relatively low maintenance, easy balcony garden, or you can do a full-on farm. It depends on your space, light and exposure and the amount of time, energy and or money you want to spend.
Balconies are usually microclimates, differing significantly from the climate on the ground.
There can even be different microclimates even on a tiny balcony. If an area is shaded, that can be one climate, if another area is exposed to the wind, that is a different climate. Also, the conditions on balconies can be extreme, with huge temperature fluctuations. Also, surface treatments can affect how hot or cool your balcony is and if it retains the heat over time.