Here's the two relevant messages, for continuity:

"Hello,There is an amazing Pinus pinea growing at Kew Gardens,London England.I think it was planted around 1850 after having been kept in a pot for some time.Must have experienced some pretty severe winters over that period of time! PS : There is a picture of it on their Web site"

"No, tunilla, not really. It depends how you define "severe" but they haven't been very severe in terms of testing Pinus pinea. A Pinus pinea survived near -18C at the NCSU arboretum in North Carolina some 20 or so years ago. OTOH, IIRC, the lowest temp. recorded in modern history in London was -13C, in one of the great freezes of the late 19th century. Even when it's cold in Western Europe, it's not really THAT cold LOL. Didn't the Dutch canals freeze about 3 or so years ago? They held ice skating events? I bet it still never went below -11C during that freeze in "Nederland".

Holm Oaks have been naturalized in SE Great Britain since the 16th century. Those trees fair very poorly when temperatures drop significantly below -18C. Therefore its safe to assume such temperatures, which would also damage Pinus pinea, have never occurred in that part of the British Isles. (or in most inhabited parts, period. There are huge holm oaks as far north as Scotland.)"

For some context . . Pinus pinea was introduced to Britain in 1548, but none are currently known more than about 150-160 years old. Within that period, the coldest winters (see link below for details) were 1854/55, 1878/79, 1879/80, 1894/95, 1939-40, 1940/41, 1941/42 (three very cold ones in a row), 1946/47, 1955/56, 1961/62, 1962/63, 1981/82. The main problem is that the figures are not usually from the same places as where the trees are, so it's difficult to know exactly what cold they survived. But I'd reckon some at least will have survived occasional freak temperatures down to about -20C.

There were some much colder winters in the 18th century (notably 1739/40), but their effect on Pinus pinea isn't recorded. The 1739/40 winter was cold enough to kill all but a very few Cedrus libani, suggesting temperatures widely in the -25 to -28°C range (and -24°C recorded at Upminster, northeast of London, a reasonably mild area).

Of northerly Pinus pinea, there used to be some mature specimens near Dunbar (SE Scotland, 56°N), but right on the North Sea coast so not exposed to severe cold. They were cut down (sad, I know not why) about 10 years ago. Young specimens (less than 25 years old) are now common in NE England, SE Scotland, and probably elsewhere in Scotland, but haven't yet experienced any severe winters.

On the Holm Oak (Quercus ilex) point, that is usually considered hardier than Pinus pinea in Britain, not too surprising as it occurs somewhat further north in the wild. A closer range match is Q. suber (Cork Oak), though that has very rarely been planted in Britain so it's hard to tell.

Resin

Forgot, one other notably cold winter, 1916/17:

Limerick, Ireland (zone 9) "33 consecutive days of frost"
Devon (zone 9) "frost held the earth ironbound even to the very edge of the sea"
South coast of Ireland (currently zone 10!!) "hard relentless frosts and unprecedented snowstorms began in November 1916 and lasted without interruption until the middle of April 1917 ... a continuous 3 weeks frost was followed in early February by heavy snow, which drifted to a depth of over ten feet [3m]"

C J Carroll (1917). The severe winter of 1916-17 and its effects on birds. British Birds 11: 26-28, cited in One hundred years of notable avian events in British Birds (2007).

Hate to think what a repeat of that would do to all of Britain and Ireland's south coastal 'subtropical' gardens!

Resin

One of my brothers was in Dublin a few years back. I was surprised when he mentioned the palms!

+oM

Thank you so much, resin, for all that precious information.After all,with all this talk and speculation on global warming,gardeners across the globe might be tempted to grow plants wich were previously considered not hardy enough.So,a glance at meteorological records shows us that extreme weather conditions turn up every so often and one must expect that they will continue to do so .I have planted three pinus pinea - one I bought as a container grown plant (1 metre high) and two others (small ones) grown as pot plants.The container grown pines offered for sale in Southern France are mostly imported from Italy.I don't know wether these would be less hardy than the "wild" ones growing not too far from here.By the way,people "in the know" around here say that it was the Romans who planted them extensively all over the South for seed production (they also planted grapevines all over the place...did they have taste!)Winters are cold,dry and very sunny were we live,summers hot and dry -this year being an exception.So, deciding wether or not to plant this or that is often problematical and so I hope you gardeners out there will continue to share your knowledge and experience with me-it is very much appreciated.Thanks!

"By the way,people "in the know" around here say that it was the Romans who planted them extensively all over the South for seed production"

Yep, or maybe earlier people - Pinus pinea has been cultivated for something like 6,000 years. According to Rikli (Pflanzenkleid der Mittelmeerländer, cited in Mirov's The Genus Pinus) it is likely only native in the Iberian Peninsula, with all the other populations introduced by man.

Resin

It's good that the original poster sought clarification, but, frankly, this is rather tahrsome to have to clear all this up.

That link Resin kindly supplied is quite annoying. I don't want to have to read through a bunch of narrative, even if color coded, to get the information I need. It's as though failed novelists in the UK become amateur weather statisticians. I had to do a lot of digging around to find that in the "cold" winter of 1963, for example, Kew was only -9.6C.
http://myweb.tiscali.co.uk/mtullett/1962-63/january_1963.htm

(why can't this chart list the typical large English cities
with which a non-native would be familiar? and sorry this circa-1996 technology web board won't automatically html-ize the link)

During the fearsome winter of 1947, it got down to a whopping 14F.

http://www.winter1947.co.uk/

At this point a couple things. I was aware the odd terrible frost pockets anywhere in the "interior" parts of the UK have been down to temps slightly below -18C as often as every 20 years or so. (I'm discounting the ridiculous valleys in the highlands of Scotland where no one actually lives that have set the UKs record lows. It's so cold in those places you can't even grow anything interesting in summer) These cold events are duly noted in at least a couple English gardening books I've read or perused. I believe Graham Stuart Thomas brings up such anomalies somewhere in his writings. But they are exactly that. It would be incorrect to assume that any random point in southern England had been below -18C more than a couple times in the past 100 years, if at all.

And as for the little ice age, and periods before 1850, the original poster mentioned the time frame of the last 150 years so that is what I was dealing with. Also it is my understanding that the accuracy of records from before 1850 or so is generally held in lower regard than modern ones. If, indeed, mature Cedrus libani died all over the UK in the early 18th century, that was truly an incredibly and devastating winter. However I would give pause by saying, has anybody actually read of bit of a newspaper from that era? The way people thought about things - discounting the great minds that live on textbooks - was different. Many of the great cedars would have been on large country estates, if they had foliar damaged I can imagine the landed gentry having their men cut it down immediately for firewood or shipbuilding or what not, rather than having it blacken the landscape while waiting to see if it would sprout again from the top. Let's put it this way, if the cedar was important enough to be written about, it probably belonged to someone important. (I'm just raising this as a possibility, I'm sure many really did die, and that the Land of Angles, once every 500 years or so, will have a winter to reminds its residents that is a lot closer to the Arctic circle than to the tropic of cancer.)

But to the matter at hand, Pinus pinea. I had to tediously scour the NCSU webpages to find the report of their freezes. I saw this tree in 1997, and it looked great. At least 30' tall and forming the characteristic flat top.

http://www.ncsu.edu/jcraulstonarboretum/publications/newsletters/ncsu_arboretum_newsletters/News12_85-07.html

You are welcome to review yourself, but for both a 2' tall and a 14' tall (the tree I saw in 1997, surely) Dr. Raulston reported "10 - no damage" for relatively young trees after a low of -19C one night, followed by -22C the next night! Then in 1994 this tree survived -17C. So we have, in a less than 10 year span, the tree survive temperatures that are no less than 3C colder than what we can assume is a "worst case" (I'm making a rough weighted average of -20C) for most of Southern England over a 30 year or greater span. And 10C colder than the records I can find for Kew during 2 of the legendarily cold winters of the entire 20th century! Remember the post originally remarked on that lovely Kew tree, which is one of my favorite trees in the garden too. (although I was last there in 99) So my supposition that the weather in the past 150 years in Southern England is not particularly taxing of Pinea pinea, compared to other ones, is a correct one. Sadly the tree is no longer at the arboretum. If I remember where it was correctly, I think it had to be removed for the new visitors center. Of course it might have perished in a hurricane, or one of the massive snowstorms that central Carolina is paradoxically notable for in the past decade.

Resin, as always, your contributions are greatly appreciated. It does not surprise me that Quercus ilex is considered a hardier tree in the UK, as I am aware it is more common. However my experience is the opposite. When I grew both I found Pinus pinea to be hardier. The report of Pinus pinea being damaged by temps in the single digits F. in the PNW somewhat amuse me, because my small plant with a mix of mature and juvenile foliage withstood very near -18C without any apparent injury. I think this could be another case of plants not hardening as well as they would in a hotter climate. Unfortunately the new owners of parents house immediately cut it down because they didn't want a tree so close to the house. It was on a south wall which probably did help a bit, but the Q. ilex was on a nearby west wall. Of course one shouldn't draw conclusions from one plant.

Actually, now that I think very hard about it, some of the juvenile foliage was a little burnt. But in the years I tended the plant from 95 or 96 to 2003, the mature foliage never showed a spot of injury and it went from a little 2' tall or so specimen with juvenile foliage to being about 6' tall with mature foliage before it got the chop.

I think tunilla will be fine with Pinus pinea provided it gets through its first few winters without one of them being a once every 30-yr. killer winter.

looking at the 1947 pages, I see some lower "grass" temperatures reported, but, of course, that is not the level at which official temperature records are kept. It is always lower at the grass level. You can be sure that in North Carolina the grass temperature was lower than -23C. (I incorrectly wrote -22 C in my post)

by saying southern England, I was avoiding, say, Shropshire, which I know is known for its cold and is probably one of the areas were

Hello to all.Thank you David for rounding off this topic.I'll keep you informed on how my pineas fare.(We could also talk on how well they burn,but that would be even more tar-some...

Haha Tunilla! Sounds like a plan. Seriously though, w/o posting your exact town, where do you fall on the USDA zone map of France? The ones I've seen only show a tiny sliver of France being zn 6. It looks to be areas in the southern intra-alp region, and the extreme NE near Germany.

I remember taking a train from Geneva to the south of France (Nice). I'm sure I took the route through the Alps, although this does not appear to be the main one anymore? It looks like more of the trains now go via Lyon. Anyhow it was a pretty unforgettable voyage. In Grenoble it was still cloudy and drizzly but an hour later we were moving through the sunny fields. Looking back you could see the distant mountains, still shrouded in fog. As we rolled on the land became increasingly Mediterranean. It seems like aspect would have a lot to do with climate in that area...are you south facing or north facing? They cultivate Trachycarpus along Lake Geneva and I even think there might be a Pinea pinea around there too, so that area is considered close to zn 8.

According to the European zone map, I think we are in 7 (minus 7°C- minus 12°C),with 6 and 8 not far away;the latter to the south of us and the former to the north.We are south facing,looking towards the Med.wich is about 50 miles away as the crow flies;it's about 100 by road.East from us is Italy (40 miles).The border follows the mountaintops all the way from Switzerland to Ventimiglia where the Alps literally drop into the sea.We have more like a hills&plateaus type of landscape in front of us.Immediately behind us begin the high Alps and so the climatic zones change rapidly with altitude.I believe they go down to 5.So yes,as you travel south from here and look back, you see the Alps -or part of it- often snow covered well into June.At that same period we are usually allready baking with daytime t° often into the 30's but no more than 15°C early morning.Our altitude is 860 m ( 2600 ft more or less).Our valley is orientated N-S and fairly broad,so it is very exposed to the sun but not entirely protected from that northerly killer wind,LE MISTRAL.It's dehydrating effect on vegetation is deadly.Plants seem to loose water faster than they can take it up .Combine that with general drought most of the time and you've got the picture.Only fools like us would dream of creating a garden around here.And yet,I'm convinced there is a lot that can be done.I produce a lot of garden compost with horse manure and so on to improve waterholding capacity ;phosphates and magnesium are in short supply so they have been added and planting wind-breaks and restoring an old well are some of the next projects.