You have a garden or a balcony and can keep your Bonsai tree outside, so you want an outdoor tree. Which one? The most important thing to consider is which conditions you can offer the tree and which species can live under these conditions. If you choose a native tree this is always a good idea, but keep in mind that many frost-hardy species need frost protection when they are planted in shallow containers.
When selecting a tree species to be kept outdoors, we suggest you take into consideration your local climate, the conditions of your garden and of course your taste.
Regions with a temperate climate are good for many species, especially most of the nice imported Japanese species can be grown successfully. Subtropical and mediterranean trees can also be chosen if they can be protected from frost, in a greenhouse for example.
In a maritime climate with moist summers you might need very well-draining soil and some species which need full sunlight might not be perfectly happy.
In a continental climate with hot summers and cold winters you will have to provide semi-shade in the summer and good protection against frost if you don't want to be limited to a few very hardy native tree species.