With rather few exceptions, the "colder districts of Australia" would be USDA zones 8 or 9. In New South Wales and Victoria as soon as you move a few km away from the seashore you will start to get some frost in winter. For example, Sydney's coastal suburbs have a minimum temperature of about 2 deg C, while on Sydney's western fringe (c. 30 km inland) the minimum is more like minus 2, or even minus 4 in frost hollows. On the tablelands near Canberra it would be somewhere around minus 8.

Just from observation of where planted Araucarias are to be seen, I would say A. bidwillii is the most cold-hardy of our Australian ones. You can see fine trees on most parts of the tablelands, so I would say it is hardy to zone 8.

A. cunninghamii grows on the coastal ranges up to quite high altitudes so I would put it in zone 9 or possibly the upper part of zone 8.

The Norfolk Island Pine, A. heterophylla, appears to be the most frost sensitive. Here in Sydney it has always been popular, so it's a safe assumption that it would have been tried almost everywhere. Yet if you travel inland from the coast, you see them in gardens and parks for maybe the first 20 km, then no more as you get into frostier areas. So this is hardly even a zone 9 plant.

[Australians may not be so familiar with the USDA zone system, which is based on the lowest temp of the coldest winter day (i.e. the day that might kill your plant), but averaged over the years. Each zone spans 10 deg Farhenheit or 4 deg C. I think zone 9 is -5 to -1 C, and zone 8 is -10 to -6]

Hi Tony,

Thank you very much for the detailed answer!

I got some seed of A. cunninghamii from a New Zealand provenance. Will try growing it. Now I feel there is some hope that I can grow it outside. If necessary I can always bring it in during freak cold spells.

Hello, I am unsure as to what USDA zone 8 & 9 refer to, however, I have some experiences with the Araucaria Genera. The natural range of Araucaria cunninghamii extends along the Eastern Fall of the divide, somewhere from the Hunter Valley in NSW to Gympie in Qld. A. cunninghamii were 'traditionally' found as emerging species in depauperate forests. They do not like wet feet! Although not a specifically frost tolerant species, they grow up here in Nth NSW in areas that experience frost, such as Tooloom and Eastern Dorrigo, where upto 10 frosts can occur annually. They don't like fire and don't respond to aboriculture as readily as Eucalypts. The NZ provenence seed are in probability derived from hybrid varieties developed for plantations and as Qld forestry is on it's 3rd rotation, I could assume that vigour and hardiness will be inherent, also, if rainfall is not limiting, growth could be as much as high as 1cm/annum. Also, A. heterophyll are grown successfully as container plants in southern locations.

Enjoy

Thanks Araucarias Dad!

Out of curiosity, have you ever tried growing some of the New Caledonian Araucaria?
Seems impossible to get seed of NC species.

Does the Klinky pine of New Guinea Aracaria klinki (specific name now changed I think) grow anywhere in Aus?
Has it been introduced?
If introduced where can it be seen in Qld?

Klinky pine maybe the emotional equivalent for the Kakoda Track as the Aleppo (Lone)pine (P.halipensis) of Gallipoli

Araucaria cuninghamii (Hoop Pine) grows well north of Gympie, it does occur well into far north Queensland and the glauca form is located on the coastal ranges of central Queensland and adjacent islands.

As for the New Caledonian species, here in Bundaberg we have one species commonly grown that is refered to as the Cook Island pine. There are some very old specimens (over 100 years old) that I suspect were introduced by the Kanakas (Pacific Island slaves that were brought in to work early sugar plantations in this area). These seem to be identical to the Araucarias I saw growing in New Caledonia. I suppose I should try to get some seed from these trees and give them a go.

Andrew.

Goted,
I agree that A. bidwillii is the hardiest Australian Araucaria. There are some places in California where this tree survived -12C unharmed in 1990 but it seems unable to tolerate similar temperatures in the Pacific Northwest... there are no large ones in Seattle, Vancouver or Portland that I know of (I keep hoping one will turn up though!) So I think it is marginal here at best but I would still try it anyways. What I have found with this species and A. angustifolia is that keeping them dry in late summer so they harden up really makes a big difference... so there may be hope for A. bidwillii here after all. A. angustifolia I think will grow just fine here in the long term.

Now as for A. cunninghamii logic would dictate it is a little less hardy than A. bidwillii, as is Agathis robusta. But they are both hardier than A. heterophylla which meets its doom around -6C (-5 if smaller). And A. cookii (syn A. columnaris, I think), if I remember right, is native to the Cook Islands and less hardy than the others, maybe to just -2C or something (I'm not 100% sure on that info...I'm trying to remember something I read a long time ago and it could have been incorrect to begin with!). If there are any other hardyish Araucarias, one to try might be A. huntsteinii from Papua New Guinea.

There is a guy in New Zealand who has some specimens of the New Caledonian Araucaria and Agathis species (as well as rare treeferns) - drop me a line and I'll give you his name (but that's all I've got, I think I lost his email!)

Also if you wouldn't mind sharing any Araucaria seed sources you do find, I would really appreciate it!

I am sourcing for quality seed of Araucaria huistenii foe planting 200 ha. Any idea where this seed can be got from?