As Peter says they can be huge plants - we have one climbing over the entrance arbour at the Auckland Botanic Gardens and it's about 3m from the Wisteria beside it and they are now intertwined. There's another one just outside my work window - it covers a 2.5-3m span of wall and is now almost 6m tall (the height of the wall - I am sure it would keep getting taller). You need a very solid structure for them to climb i.e. a concrete or metal structure. We've had visitors report them pulling down old sheds, and killing cabbage trees they've climbed over.