I'v only heard of those symptoms on another plant and what they did is cut off the main trunk and let new growth occur as the whole trunk was infected. Where do you grow it in the garden? Australian plants must surely need to be grown agains a south facing wall or greenhouse. Good luck anyway. I live in the uk and it was a nasty winter see if you get more feedback.

As said above, cut the infected part off and keep your fingers crossed Norrie..Sorry to sound so negative but it was a really bad winter last year and TFs can only survive down to -5 unprotected..