They are doing quite well in the UK, despite its rainy and humid summers so at least that shouldn't be any problem.

"The mother tree, from which the acorns came, has experienced temps around 0 degrees F in Denmark"

Yeah but an average winter in most of Denmark is zn 8, so in theory it will be a little easier to establish there. I had one die in the winters of the 1990s, but not one of the colder winters like 1994. Maybe 1996? In any case it clearly wasn't particularly hardy...for example...a small Pinea pinea survived the same winter. I think it died at 0F. Quercus suber was hardier too.

Heat & humidity is generally not nearly as much a problem for the large flora of the Mediterranean as it is for those of California. There is/was Quercus ilex, suber, and Pinea pinea at the NCSU arb...and at Williamsburg...and various other Med. species I could mention, while Californian trees other than S. semprevirens and a couple others are very rare there. Certainly no California BLEs come to mind as doing well in the SE but I could be forgetting a couple. Compare Arbutus x andrachnoides which is sold by Woodlanders in SC and has been an absolute trouper for me int he past 3 summers, with Arbutus menziesii which is utterly ungrowable anywhere on the east coast.
So you could certainly try it but expect it to die in a cold winter, not a summer. BTW though it is interesting to grow as a novelty, if you actually are planning a landscape around it you should be aware they are one of the most sombre looking trees I know of, and they cast dense shade. Search this forum for the picture of the one I posted previously for poaky (sp?).

"despite its rainy and humid summers "

yeah but it's not the same kind of rainy & humid...I doubt anywhere in the British Isles has ever seen a dewpoint above 70F...but I don't think that's a figure the Met. Office actually keeps track of anyhow. (even in Celcius) Kinda strange the way they are about stuff like that...they also don't keep inches (or cm) of snow except anecdotally...just "days of snow falling" and "days of snow lying on ground". Plants like Catalina Ironwood and various CA Ceanothus grow quite well in SE England, but not at all in the US SE. Their dewpoints are a little higher than California's, generally speaking, but nowhere near what is experienced in the US SE.

BTW I have an F2 seedling of the hybrid Q. X turneri. (Q. ilex X Q. robur) This was from an import of rare oak seeds in the early 2000s that has never been repeated. (I think the defunct Arborvillage might have gotten their Q. libani in the same batch, because I think Woodlanders listed it, too) For the first few years it tried to hold onto its leaves but grew poorly. Then our stronger seasonality compared to western Europe appeared to cause some epigenetic change in it. No kidding. It doesn't even remotely try to hold its leaves now, no matter how mild my autumns are, and they usually are. This is the first year since 2006 that I had a freeze before Thanksgiving. OTOH, it is now growing somewhat more vigorously, but they are still slow.

There is (was, probably) an F1 in Arlington, VA, that was imported from Belgium as a grafted plant in the late 50s. I think it probably holds its leaves better, but was astonishingly small for its age. Contemporaneously planted Q. virginianas were twice as large, and they aren't exactly know as being speedy gonzales. Not something I'd mess around with at this point unless I knew I'd live to 120 LOL. I just keep it as a curiosity...no autumn color, either.

This post was edited by davidrt28 on Sun, Dec 29, 13 at 18:58

I would try it if you have acorns, what do you have to lose? I tried a Turner's oak here in zone 6 Pa. It was supposed to be a seed grown seedling. The Turners being Q. Ilex XQ. Robur, if I remember right. Most are grafted, but mine was said to be from seed. It is illegal for shipping of certain plants from the UK, the kind person I got mine from found a loophole, but it never woke up the next spring. The spring following that, I saw a plant with a thin wispy stem and pulled it up thinking it was a weed, and saw evergreen-like thick leaves, and wondered if the Turner's oak was dormant for a year, then came up. I have since planted a Live oak "late drop" hoping for the best with that.