Plants should be grown, not ripped out of forrest's.
I notice the Australian garden features a large Xanthorrhoea (grass tree).
I'm very disappointed as these plants are not grown, but ripped out of forrests. What makes this sadder is that this plant would be many hundreds of years old (definitely before white people arrived) and once they are removed from there natural landscape, die a very slow death.
I think it's disgraceful that a garden exhibition can just rip the plants out of the native forrests - the RHS should have a critea that the plants on display should be grown.