I have never grown them,but always have something rated zone higher or more in the yards. One thing is..plant not only where its warmest...but try to find that and where winds are blocked,a huge plus. Also,it helps big time for sunlight to get to the base of the plant and warm the soil. Especially in winter.

btw- I'm in the SF bay area,USA. Often compared to Melbourne by those from Australia.

The plant is currently in the unheated garage under a CFL light. its warmer in there than outside. Would that suffice? Thanks for your reply

That's a good plan...get it used to cool but not icy cold nights that would damage it. Once milder weather comes around,don't rush it into sun or harsh light...gradual. Full shade for a while- no direct sun- then more light progressively.

Also for all the very marginal once planted out? Make it a habit to cover and even warm in near freezing nights for at least the first two winters. If it isn't doing well after that? Its not to be.

i plant my trees that are not cold-tollerant next to a structure or large bush. usually on the sunny side, but a structure or other plant can help keep cold winds from damaging them.

Thank you all for your help. i take it out during the day when its a bit warmer an bring it back in when at night when temperatures are quite cold