Visitors are often surprised when they see 'Goldheart' vigourously growing on a West facing wall. Although English Ivy (Hedera helix) is hardy in this climate, it is usually knocked back by sub-zero weather when it grows above snow cover.
In fact my plant took years to set down a root system that would support it's upward movement. It also had a couple of false starts, planted against a fence, it died back every Spring until it reached an adjoining wall and then really took off.
I realize now that the fence was too thin to provide any insulation to the plant, whereas the wall provided enough warmth both from inside the house ( my neighbours actually) and also from holding onto the heat from the Sun even in the coldest days of winter.
Now that the plant is fully established it even holds on to some territory on the fence, but not as vigourously as it does on the wall.