I too would like to know the answer to this question. If you have ever seen a specimen grade tree of this variety you know what I mean. the "tubers" or above ground root structures are so intricate & magnificent. How do they do that?

I have seen pics where it appears the tree's are bound w/ some sort of red strap like material to manipulate them. maybe it's a trade secret... or just time.

H.

Like with any bonsai it's a combination of careful manipulation and time.

Do you think the tree is raised at each re-potting?

H.

Most likely yes. Most Ficus don't mind exposed roots, they usually start off from seed as an epiphyte. Fine roots would be trimmed off to give the effect you want. You should try searching for bonsai Ficus on youtube, there are a lot of videos on the subject which are helpful.