It's going to be borderline at best. Any long term success I've seen with it in this area is in containers that were afforded sufficient winter protection, as it will experience foliar damage at around 25F and die off much below that. Not sure what the purple markings are - perhaps too much water?

In attempting to sort out Astelias I'm starting to think that A. nervosa is the hardier/better one for our climate. A plant labeled as this has persisted for years at the Washington Park Arboretum in the New Zealand alpine garden for at least 10 years with no damage. Another one at Jungle Fever in Tacoma is very large, no label on it but it appears to be the same animal I have seen labeled as A. nervosa at Cistus Nursery. Of course labels can be wrong but A. chathamica I think may be a smaller and less hardy plant (this would also make sense considering its origin on the relatively mild Chatham Islands). I have also observed that frost damage is less likely to occur if the plant is kept on the dry side and discouraged from making active growth into the fall. I think burgundy sounds like too wet also - they need good drainage.

I have had several Astelias nervosas(Red Gem) from Cistus and (Westland?) from Heronswood overwinter fine for about four years now. The A chathamica (it is the larger one) on the other hand has proven less hardy for me but I am going to try one again maybe next winter perhaps in a dryer spot. I have some in containers that are leftovers from past attempts. The first winter I think they would have been OK but were undermined by voles/mice with a good stash of Styrax obassis seeds underneath! BTW I have them all in raised beds with pretty good drainage. I would think you would be fairly successful in zone 8b with excellent drainage. I say give it a go, if you are a bit worried I would wait until next spring to put them in the ground to give them a whole season to get somewhat established. Good luck!

Thanks for the help. :-) I would not have guessed too much water since I tend to go the other way and not water my plants enough. But it did come looking that way from the nursery and it has been a wet summer. I guess what I'll do is wait until next spring and plant part of the clump out in a spot with excellent drainage and keep the rest of it in a pot for insurance. I actually had A. nervosa seeds in the past,unfortunately they either didn't germinate or I killed the seedlings - can't remember which. That's a really pretty garden shot bamboomary.