I work at a nursery in Vermont so I'm constantly finding things in our nursery stock (disregarded and left for dead plants mainly). most are in deep nursery pots with their original soil from the vendors. The "soil", if you can call it that has the consistency of meatloaf (for the lack of a better analogy). Is it ok for the tree to remain in said potting medium until next spring or should I get it into better stuff now? I'm very new to the world of bonsai so please forgive my seemingly naive questions.