I observed the same, if Nepenthes were growing in volcanic soil. I
once was given a plant perfectly growing when visiting another grower
in Germany. I transported the plant to my home by car (around 2 hours
drive) After that the plant did not grow any more. A check after some
weeks showed that most of the roots were broken or cut by the sharp
lava particles.
I think some soft substance in the medium like peat, Sphagnum,
bark... helps to prevent such damage which otherwise may occur when
moving plants.
Andreas
Andreas Wistuba; Mudauer Ring 227; 68259 Mannheim; Germany
Inet: a.wistuba@dkfz-Heidelberg.de / a.wistuba@carnivor.rhein-neckar.de
Phone: +49-621-705471 Fax: +49-621-711307