Bashania Genus - I have two members of this genus - Bashania fargesii, and B. qingchengshanensis.    Not widely grown in the US B. fargesii has earned a reputation for hardiness in Europe and Asia. Unfortunately for me, mine was set back by vole attacks during the first couple of years in the ground and it has not yet had a chance to establish, nor exhibit its true hardiness. I  culled the original site and have established a second planting of it hoping it has a chance to establish.   B. quinchengshanensis is shorter and has a more elegant form with similar hardiness.
    The B. fargesii that I saw in the Netherlands were beautiful and large, 20 feet by 1.25 inch diameter culms with long dark green leaves and a faint blue/white powdery blush on young culms.  These bamboos are among the first to shoot in my garden in mid to late March and they seem to tolerate cold temps without sustaining damage. Large culms of B. fargesii - 30 feet by 2 inches, have been grown in Switzerland.
  It is my understanding that this B. fargesii can be extremely aggressive and that combined with its hardiness may make it a suitable screening species in zone 6.