I only cut tap roots when they're babies. You can still do it, but the result would be more centipede-type, I fear.

What does that mean, centipede type?

Amanda, the best response I can give is this link to this very site! Centipede roots are from cutting the bottom off of the caudex and often gluing a disk onto the bottom to block growth in the center of the plant, and only allow the roots to grow on the periphery. I believe this is most often done to adult plants.

http://forums.gardenweb.com/discussions/3460082/from-thailand-with-love

This is the picture originally posted by Rick:

When I trim the taps at a young age, I now don't place anything in the center, and get these results. (some are centipede-like, some not - but they will grow as the plant grows.)

http://forums.gardenweb.com/discussions/4078842/repotting-some-plants-dont-look-pagan?n=8

I like the centipede roots, but I think obesum look better with large roots. If you decide to do this, it may take awhile for them to get large.

You are best to repot without trimming the Haddock root off. This plant will have a nice caudex as it grows larger. Already has nice twisted roots.

As Jedoba mentions. The centipede root is best for Arabicums &/or TS's.

You can trim off the small roots (green) that come off of the sides of the Caudex (trunk) of this tree, if you prefer a smooth look to the caudex. This is completely a personal choice.

Rick

I like the twisted look of the Obesum roots I would do as Rick say's and then replant it at the same depth. When It is older you can hang till soft and move the big roots around for a great look. IMHO

This has given me a lot to think about, thanks guys!