Evan, that clump is about 8 years old. It will die back in the winter. When Musa are young here, we mulch them with straw (8-12"). Some people cut them just ahead of a hard frost and mulch; others let them freeze to the ground, remove the mush, and then mulch. Some don't do anything. M. basjoo does very well here. We are zone 6b. Our coldest is usually single-digits but 0ยบ or below is not unheard of.
You'd almost swear you were in the Tropics looking at that, wouldn't you?
