Posted: 26/09/2012 at 21:36
These trees are often grown as bonsai. If it is reasonably healthy, you could try tipping it out of the pot, root pruning and popping it back in the same pot... The top will probably need pruning or the roots will not be able to sustain the top growth.
Pruning the top growth at his time of year is not such a good idea as it can stimulate tender shoots just before the cold weather. Wait till leaf drop or the early spring. Bonsais must not be over fed or they grow too fast so use a seed compost for best results.