A suggested update. The iGarden profile of the "Lavender Trumpet Vine" - or Clytostoma
callistegioides - states that it is not thought to be frost hardy. Surprisingly, given its lush appearance it is indeed hardy down to at least minus 8C. I have one in my Canberra garden and it was flourishing when I bought this house nearly 30 years ago. It is in an exposed position and it has remained vigorous ever since, through every frost and drought over the years. The vine is very lush and dense and the flowers are pretty. The only caution it that it is a vigorous tendril climber that can invade surrounding shrubs.