This is actually my parents' garden and there's little structure to it as yet. Interests range from orchids, through bromeliads to proteas, the usual palms and of course nanas and canna. Update 2011, most of it's now changed after the last winter. The only guaranteed low was -15 C on an old max/min thermometer on the house wall. The electronic sensors stopped working at -12C, but I think that was the batteries at fault! I leave it to you to guess the actual temperature.