Posted: 21/03/2014 at 07:03
I can't imagine successfully containing a gunnera in a pot, let alone in a front garden! They grow bigger than some trees!
Slightly smaller plants with similar striking architectural qualities are Astilboides tabularis, Rodgersia pinnata and Rheum palmatum, but I do not know whether they would cope with a Canadian winter - maybe someone here would know? http://www.canadiangardening.com/forum/