I tried a few new perennial food crops this last year--chaya, cassava, and Chinese water chestnuts, all of which are borderline here (zone 8b, verging on zone 9). The chaya and cassava died, but the Chinese water chestnuts made it (the reeds died back, but they came back in spring). I am raising them in shallow repurposed stock tubs and didn't do much to protect them, because I'm lazy. So yay for Chinese water chestnuts! I will keep raising them and maybe find some more/better containers for them, too.