Have you thought about kudzu?
Easy to grow and requires very little care.
I wasn't entirely sure what Kudzu was, so I googled it.
Pueraria lobata, probably will not grow well in Southern Australia because of frosts. However it does very well in North Eastern Australia, so much so, that New South Wales have delcared it a noxious weed. Similar moves to ban the plant in Queensland. There is work being carried out to introduce a 'biological' control. I hope this doesn't mean something like Cane Toads!
Interesting how some plants that are quite innocent in the right conditions, can become out of control in others.