experience has shown me that neither scabrida nor robusta hold up much below +10F, despite what the 'book' says. and when the fargesias topkill as it sounds like yours did, they remain stunted little things that for me are less than 6 inches tall after a couple of years. i have finally dug most of mine out in hopes of getting them to size up in the containers and then perhaps to trade them away.

f. dracocephala 'rufa' is the one to try in z6, it is both cold & heat hardy, plus sizes up quickly. sadly for me the arrow also has been less hardy than purported remaining under 6 feet after 5 years, and has never survived winter above ground. however pseudosasa viridula, which is arrow with 3 instead of 1 branch at the nodes, has survived every winter was over 9 feet in its 3rd year, to me a much more attractive form in every way with added hardiness.

Thanks for the advice. I did plant a two gallon rufa on the other side of the house that looks great. I will wait to see what happens and may try to locate that pseudosasa viridula if I can locate it.