Maybe take some time to really learn about the tree before making big decisions... not every tree needs chopping immediately and sometimes it's better to first see if you can keep such exotic and unfamiliar ones alive for a while - a year wouldn't be too long. Once you feel confident about every aspect of care, and know when the best time is to do work on the tree, then you'll be ready and not discouraged if things don't go well - certainly you'd have a better idea of why things failed and not just be left guessing.... you'll have knowledge to apply to other trees in future.

So let it grow for this year?

While learning from it and other sources. It's what I would do and have done in the past... and too often have found that even with supposedly the most appropriate care I was able to give some things, the fact I'm not actually in e.g. Africa (or Brazil or Japan) and working on whatever tree might be growing right outside my door in easily available soil gave the trees in question and myself some hard lessons, plus avoided the eventual need to actually begin bonsai-ing them by the time I felt I'd learning enough. Crummy, but ... you know!

This post was edited by moochinka on Thu, Jul 10, 14 at 12:32

They are extremely slow growers, and the restriction of being in a pot may be all it takes.

If you "chop the trunk" you may kill the tree, so really research this.

Here is a link that might be useful: Care of baobab bonsai