These type of trees are usually simply nursery stock from garden centers. My husband mostly uses these type of trees to create our Bonsai Trees and these do not need to be actual trees. Shrubs and even vines can work just as good for bonsai starter trees. One can even dig up a tree in the wild! Any tree or shrub that has a good Bonsai potential can get you started.
Let me know if you are interested in growing bonsai trees and my husband can get you started and make a beautiful Bonsai for you, planted in a pre-selected Bonsai pot sized specifically to your tree of choice. This could easily become your next hobby.
Please check out my page on Bonsai to read more and see more pictures of our Bonsai collection.