Re: Coconuts and cold tolerance
I think if anyone down in marginal areas wanted to try they should order the Malayan yellow dwarf (that Chinese variety can't be shipped here) variety from florida-coconts.com, plant in extremely well drained soil. Plant it next a south facing wall, black rock ground cover, and maybe next to a pool.
Also check out Sepp Holzer, the guy is growing stuff in Austria at at 1500 meters that people said he couldn't. His techniques may help with zone pushers. I myself will use as many as I can for my bananas. An inspiring individual.