I found a grove of large culms and have permission of the owner to
take a few to grow. There is no way of course that I can transport a
20' culm with roots.

Assuming that I can dig out a few small clumps of the rhizomes, to
transplant, do you think it would be ok if I cut the culms very low to
1 or 2 feet? I know it is the rhizome root mass that carries the
energy of the plant for next season, but I wonder if it will die
without the culms/leaves until next spring?

-- David