The largest, oldest most Northerly Palm Tree in the world

[Mauna Kea Cloudforest]

Can you guess where the largest, oldest most Northerly palm tree is located?

Take a look at the statistics for this canary date palm in the picture below:

Location: Fota Arboretum, Fota, Co. Cork, Ireland
Latitude: 51.8972° N (Same latitude as Alaska, sun angle is 13 degrees at Winter solstice)
Date Planted: 1896 (117 years old)
Height: 9 m
Girth: 1.55 m

(http://www.treecouncil.ie/heritagetrees/440.htm)

[Daryl]

Axel, nice old Canary, but I don't think it is the most northerly palm as such...maybe as your title suggests it is the 'largest' northern palm, but there are Trachycarpus growing further north than this one..at 54.9° N in Scotland...perhaps elsewhere as well?

But that palm in the photo must certainly take the record for a Phoenix!

Any idea where the most southerly palm is located?

Daryl

[trioderob]

there are palms growing outside in Norway.

[Mauna Kea Cloudforest]

Axel, nice old Canary, but I don't think it is the most northerly palm as such...maybe as your title suggests it is the 'largest' northern palm, but there are Trachycarpus growing further north than this one..at 54.9° N in Scotland...perhaps elsewhere as well?

But that palm in the photo must certainly take the record for a Phoenix!

Any idea where the most southerly palm is located?

Daryl

Well, I doubt those trachys are 117 years old, and definitely not as tall either. Now I wonder if that canary is still there with the latest European nightmare Winters they've been having.

[LJG]

Well, no fear of Fusarium or the Palm Weevil

[Tassie_Troy1971]

" Any idea where the most southerly palm is located? "

Dont know but New Zealand and South America some where i guess . I have 40 species outdoors @ 42.5 deg south

[bgl]

"Largest, oldest most Northerly palm etc." is really a moving target. That 9 meter tall P. canariensis may very well be the largest palm that far north but if there's a 6 or 7 meter tall palm a few miles north of there, then THAT palm could easily also be the "largest, oldest most northerly palm" since it's further north than the CIDP.

This old thread may be of interest, even though unfortunately the links don't seem to work. Presumably the sites are defunct.

http://www.palmtalk.org/forum/index.php?/topic/12591-washingtonia-robusta-and-butia-capitata-in-aalesund-norway-at-latitude-625/

[Mauna Kea Cloudforest]

"Largest, oldest most Northerly palm etc." is really a moving target. That 9 meter tall P. canariensis may very well be the largest palm that far north but if there's a 6 or 7 meter tall palm a few miles north of there, then THAT palm could easily also be the "largest, oldest most northerly palm" since it's further north than the CIDP.

This old thread may be of interest, even though unfortunately the links don't seem to work. Presumably the sites are defunct.

http://www.palmtalk.org/forum/index.php?/topic/12591-washingtonia-robusta-and-butia-capitata-in-aalesund-norway-at-latitude-625/

Yes, you're right, the heritage site lists that one too, I figured it was close enough to not matter. There's also no data on the planting date of the second one, so I picked the other one.

I tried to Google any of the palms in Norway, could not find a thing on them. However, the claim that it rarely gets below -5C in Ålesund, Norway is backed up by the data. See http://weatherspark.com/averages/28840/Alesund-M-re-og-Romsdal-Norway

Quoting the site: Over the course of a year, the temperature typically varies from 33°F to 61°F and is rarely below 26°F or above 68°F.

That's actually USDA 9b, but I wonder which palm species could take the constant day/night temps near freezing during the 2-3 months around Winter solstice, not to mention that at that latitude, at Winter solstice, sunrise is after 10AM and sunset is before 3PM, not to mention nearly constant cloud cover and constant rain. Also, 30% of the time during the months of Dec, Jan and Feb it's below freezing. Even if it's not far below freezing, it's still below freezing for a considerable amount of time.

[Explorer]

Well that CIDP is growing at the same latitude as where you will find the most southerly polarbears in James Bay, Canada. And in Southern Norway they have the most northerly growing Trachycarpus fortunei and Musa basjoo at 59 degrees latitude North! Its on a island in a fjord that this garden is situated.

florogfjare.no/norsk

florogfjare.no/english

Alexander

Edited December 25, 2013 by Explorer

[Mauna Kea Cloudforest]

Pretty impressive, I checked out some of the pictures. That's pretty darn far North. Consistent with a cold USDA 9b zone. The extreme long duration of the 9b type wet cold (26-32F) prohibits planting the more typical 9b palms which can't take cold without warm up above freezing during the day. Goes to show you that you need more than the USDA zone to determine what you can grow.

[Explorer]

That garden is not that far from Stavanger.

Alexander

[Zeeth]

My fridge is USDA zone 10a, so you have a point. I wonder though if there are any Trachycarpus growing within the arctic circle, because the area you posted is apparently only 4 degrees south of it.

[stygiana]

Hi there,

Axel, great post and than kou, this Irish CIDP is remarkable. Unique! Just one thing, be careful about the allegations of norwegian. I don't think it is USDA zone 9b. The 33°F (0,5°C) average minimum temperature for the coldest month should not be confused with the average annual temperature.

Even if norwegian is in a mild micro-climate, it sounds far exaggerated.

How can you be 9b with 32°C almost every morning during 3 or 4 months on a typical average year and a record low of around -15°C at best (5°F).

The Wikipedia page for Ålesund and norwegian claim a long range lowest temp of -11°C (12°F). But there is a "Citation needed" after this quote on the Wikipedia's page. And when you look for more accurate data (http://www.mherrera.org/temp.htm), you find this below (attached thumbnail).

OK, Ålesund is not mentioned, but the other stations help to have an idea about what are the extremes on the Norwegian western coast.

On weatherunderground, I found that they've already hit -6°C this year, hit -13°C last year, -9° in 2011, -8°C in 2010, -10°C in 2006, etc.

I know too well what it's like, I had such claims when I started my palm hobby a few decades ago, while I lived in a USDA zone 7b (but believed it was much more, simply because I had planted in the ground lots of cacti, yuccas and palms). In fact, many of my enthusiastic friends in other cold regions exaggerated more or less the same. But reality was a different matter...

What norwegian considers zone 8 a little further away from his place is probably only 7b. And I guess the best, most unique and sheltered spots over there are 8b.

Come on guys, do you realize? 8b at this latitude, it's already unique in the world and there's no need to overdraw really.

However, you are quite right Axel in pointing out that a good USDA zone is not enough to determine what you can grow: with such little summer heat (average minimum for the warmest month is 11°C / 51°F and average maximum is only 16°C / 60°F !), there is a clear limit. But still, I have always admire this part of the world for its unbelievable mild climate regarding its latitude.

[Mauna Kea Cloudforest]

My fridge is USDA zone 10a, so you have a point. I wonder though if there are any Trachycarpus growing within the arctic circle, because the area you posted is apparently only 4 degrees south of it.

How's the coconut coming along in your fridge? You've presented by far the best argument I've ever heard for why the USDA zones provide extremely limited growing info.

Hi there,

Axel, great post and than kou, this Irish CIDP is remarkable. Unique! Just one thing, be careful about the allegations of norwegian. I don't think it is USDA zone 9b. The 33°F (0,5°C) average minimum temperature for the coldest month should not be confused with the average annual temperature.

Even if norwegian is in a mild micro-climate, it sounds far exaggerated.

How can you be 9b with 32°C almost every morning during 3 or 4 months on a typical average year and a record low of around -15°C at best (5°F).

The Wikipedia page for Ålesund and norwegian claim a long range lowest temp of -11°C (12°F). But there is a "Citation needed" after this quote on the Wikipedia's page. And when you look for more accurate data (http://www.mherrera.org/temp.htm), you find this below (attached thumbnail).

OK, Ålesund is not mentioned, but the other stations help to have an idea about what are the extremes on the Norwegian western coast.

On weatherunderground, I found that they've already hit -6°C this year, hit -13°C last year, -9° in 2011, -8°C in 2010, -10°C in 2006, etc.

I know too well what it's like, I had such claims when I started my palm hobby a few decades ago, while I lived in a USDA zone 7b (but believed it was much more, simply because I had planted in the ground lots of cacti, yuccas and palms). In fact, many of my enthusiastic friends in other cold regions exaggerated more or less the same. But reality was a different matter...

What norwegian considers zone 8 a little further away from his place is probably only 7b. And I guess the best, most unique and sheltered spots over there are 8b.

Come on guys, do you realize? 8b at this latitude, it's already unique in the world and there's no need to overdraw really.

However, you are quite right Axel in pointing out that a good USDA zone is not enough to determine what you can grow: with such little summer heat (average minimum for the warmest month is 11°C / 51°F and average maximum is only 16°C / 60°F !), there is a clear limit. But still, I have always admire this part of the world for its unbelievable mild climate regarding its latitude.

The site I used is actually a neutral weather data cruncher. It takes the data straight and turns it into a report. Since the Wikipedia page has no citation, I trust the data more than Wikipedia. There are spots on the Norwegian coast that are indeed 9b, and the Irish Coastline even features USDA 10a. But, as many have already pointed out, a USDA zone means little when it comes to growing stuff.

[Halekuma]

No way that place in norway is 9b, even that place in south Ireland where people grows rhopies is a marginal 9b, one bad winter and the more tropical palm growing there will be CIDP. My place has been consistently a 10a zone in the last decade but I know most of my 9b palms can die a bad freezing night...

[Mauna Kea Cloudforest]

No way that place in norway is 9b, even that place in south Ireland where people grows rhopies is a marginal 9b, one bad winter and the more tropical palm growing there will be CIDP. My place has been consistently a 10a zone in the last decade but I know most of my 9b palms can die a bad freezing night...

The Norway spot sure is according to the weather data, worst min is 26F, but these are just tiny microclimates. Not much use to have USDA 9b if you have freezes that last day and night even if they're above 26F, only 8b palms survive that type of cold. A rhopie could not handle that length of cold. So if you have a high of 29F and a low of 26F and this goes on for days, there is no way that a rhopie will survive.

However, Ireland is a completely different story, definitely true cool USDA 9b and 10a since it's an island in the Gulf stream. The CDIP actually grows in what is labeled as USDA 9a. See map in this link: http://www.plantmaps.com/uk_plant_hardiness_zone_map.php. USDA 10a in Ireland does support rhopies.

Take a look at Tresco island Abbey Gardens in the far West of England : http://www.tresco.co.uk/what-to-do/abbey-garden/default.aspx. Then you begin to realize what's also possible in Ireland.

[stygiana]

My fridge is USDA zone 10a, so you have a point. I wonder though if there are any Trachycarpus growing within the arctic circle, because the area you posted is apparently only 4 degrees south of it.

How's the coconut coming along in your fridge? You've presented by far the best argument I've ever heard for why the USDA zones provide extremely limited growing info.

Hi there,

Axel, great post and than kou, this Irish CIDP is remarkable. Unique! Just one thing, be careful about the allegations of norwegian. I don't think it is USDA zone 9b. The 33°F (0,5°C) average minimum temperature for the coldest month should not be confused with the average annual temperature.

Even if norwegian is in a mild micro-climate, it sounds far exaggerated.

How can you be 9b with 32°C almost every morning during 3 or 4 months on a typical average year and a record low of around -15°C at best (5°F).

The Wikipedia page for Ålesund and norwegian claim a long range lowest temp of -11°C (12°F). But there is a "Citation needed" after this quote on the Wikipedia's page. And when you look for more accurate data (http://www.mherrera.org/temp.htm), you find this below (attached thumbnail).

OK, Ålesund is not mentioned, but the other stations help to have an idea about what are the extremes on the Norwegian western coast.

On weatherunderground, I found that they've already hit -6°C this year, hit -13°C last year, -9° in 2011, -8°C in 2010, -10°C in 2006, etc.

I know too well what it's like, I had such claims when I started my palm hobby a few decades ago, while I lived in a USDA zone 7b (but believed it was much more, simply because I had planted in the ground lots of cacti, yuccas and palms). In fact, many of my enthusiastic friends in other cold regions exaggerated more or less the same. But reality was a different matter...

What norwegian considers zone 8 a little further away from his place is probably only 7b. And I guess the best, most unique and sheltered spots over there are 8b.

Come on guys, do you realize? 8b at this latitude, it's already unique in the world and there's no need to overdraw really.

However, you are quite right Axel in pointing out that a good USDA zone is not enough to determine what you can grow: with such little summer heat (average minimum for the warmest month is 11°C / 51°F and average maximum is only 16°C / 60°F !), there is a clear limit. But still, I have always admire this part of the world for its unbelievable mild climate regarding its latitude.

The site I used is actually a neutral weather data cruncher. It takes the data straight and turns it into a report. Since the Wikipedia page has no citation, I trust the data more than Wikipedia. There are spots on the Norwegian coast that are indeed 9b, and the Irish Coastline even features USDA 10a. But, as many have already pointed out, a USDA zone means little when it comes to growing stuff.

I'm sure the site you mention is neutral and has reliable data (they actually correspond to the national official data). What I meant concerned the interpretation one can make of the following sentence:

"Over the course of a year, the temperature typically varies from 33°F to 61°F and is rarely below 26°F or above 68°F. "

We are not talking about the average annual minimum (which is what is taken into account for the USDA zones), but about, first, the average minimum temp of the coldest moth and second the average max temp of the warmest month.

For example, it corresponds to the 46°F to 70°F range of San Francisco, Ca.

If 46°F was the min temp to take into account for USDA zones, then San Francisco would be 11b...

Second, what does "rarely below 26°F" mean? What is rare? The data I gave you are just as reliable, but here they are again: "they've already hit -6°C (21°F) this year, hit -13°C (8°F) last year, -9°C (16°F) in 2011, -8°C (17,5°F) in 2010, -10°C (14°F) in 2006, etc."

If one takes the average annual minimum (as listed just before, but over the last 10 years), it gives a data of 19,8°F. Which makes it 8b, bordering 9a.

Which is quite enough for me to be amazing, nearly magical... Such a zone up there... Mild under the aurora...

And that's only the last 10 years which, apart from one exceptional winter (2012) and another rather bad one (2006), were often well above last century's average. If one counts over three decades and include maybe a lightly lower ratio of exceptional events like 2012, but compensates it with many years with colder mins, I'm not sure we would have a much better number in the end. If any better at all.

26°F is not their worst temp, only a limit they just "rarely" brake.

"Rare" may simply mean that only once or twice a year the thermometer goes below 26°F. For the official administrations in charge of weather in Europe, "rare" is usually for "a phenomenon which happens less than 3 days a year". For a phenomenon which happens less than once a year, it is usually called then "very rare" and if it's only once per decades, it is called "exceptional".

Nevertheless, even 8b bordering to 9a is simply amazing, awe-inspiring at such a (nearly polar) latitude!!!

[stygiana]

No way that place in norway is 9b, even that place in south Ireland where people grows rhopies is a marginal 9b, one bad winter and the more tropical palm growing there will be CIDP. My place has been consistently a 10a zone in the last decade but I know most of my 9b palms can die a bad freezing night...

The Norway spot sure is according to the weather data, worst min is 26F, but these are just tiny microclimates. Not much use to have USDA 9b if you have freezes that last day and night even if they're above 26F, only 8b palms survive that type of cold. A rhopie could not handle that length of cold. So if you have a high of 29F and a low of 26F and this goes on for days, there is no way that a rhopie will survive.

However, Ireland is a completely different story, definitely true cool USDA 9b and 10a since it's an island in the Gulf stream. The CDIP actually grows in what is labeled as USDA 9a. See map in this link: http://www.plantmaps.com/uk_plant_hardiness_zone_map.php. USDA 10a in Ireland does support rhopies.

Take a look at Tresco island Abbey Gardens in the far West of England : http://www.tresco.co.uk/what-to-do/abbey-garden/default.aspx. Then you begin to realize what's also possible in Ireland.

Axel, marvellous places indeed, thanks for the photos. I really like visiting UK and Ireland and I admire their professionalism and enthusiasm for gardening and acclimatization.

I wish you will not find me too "pernickety", but Tresco is not exactly southern Ireland. The only place which might be compared to Tresco in Ireland is Valentia (plus a few tiny micro little spots in that region). And Valentia island is maybe a 10a, but just it. (And summers are cooler too, but that doesn't count for USDA zones, only for the range of plant you can grow)

Note taht almost all the Rhopies frozed to death in 1985 and 1987 in Treco with temps of −7.2 °C (19.0 °F).

The Scilly isles (where Tresco is located) are the only true 10a in Britain. The westernmost Cornish coast, on the mainland is barely it. Barely.

Concerning Ålesund in Norway: "worst min is 26F, but these are just tiny microclimates." The worst min is much colder, as mentioned above.

Thanks again for these pics, as I think that any serious plant acclimatizer has to visit these places if one comes to Europe.

Besides, they are great lansdcapers. I love the way the gardens are done at Tresco.

The canarian plants look better there than here. Just like if it had become too hot and too dry for them here now, while they seem to find in Tresco what they enjoyed in the Canaries during the ice age (while the rest of Europe was frigid and dry then, the Canaries were quite humid, rainier than today, and mild).

Many of the Canarian species they have in Tresco (Euphorbia mellifera, Isoplexis, etc) just look OK here in small areas which seem to be the last cool and humid remnants of what once was a bigger ecosystem.

[Mauna Kea Cloudforest]

My fridge is USDA zone 10a, so you have a point. I wonder though if there are any Trachycarpus growing within the arctic circle, because the area you posted is apparently only 4 degrees south of it.

How's the coconut coming along in your fridge? You've presented by far the best argument I've ever heard for why the USDA zones provide extremely limited growing info.

Hi there,

Axel, great post and than kou, this Irish CIDP is remarkable. Unique! Just one thing, be careful about the allegations of norwegian. I don't think it is USDA zone 9b. The 33°F (0,5°C) average minimum temperature for the coldest month should not be confused with the average annual temperature.

Even if norwegian is in a mild micro-climate, it sounds far exaggerated.

How can you be 9b with 32°C almost every morning during 3 or 4 months on a typical average year and a record low of around -15°C at best (5°F).

The Wikipedia page for Ålesund and norwegian claim a long range lowest temp of -11°C (12°F). But there is a "Citation needed" after this quote on the Wikipedia's page. And when you look for more accurate data (http://www.mherrera.org/temp.htm), you find this below (attached thumbnail).

OK, Ålesund is not mentioned, but the other stations help to have an idea about what are the extremes on the Norwegian western coast.

On weatherunderground, I found that they've already hit -6°C this year, hit -13°C last year, -9° in 2011, -8°C in 2010, -10°C in 2006, etc.

I know too well what it's like, I had such claims when I started my palm hobby a few decades ago, while I lived in a USDA zone 7b (but believed it was much more, simply because I had planted in the ground lots of cacti, yuccas and palms). In fact, many of my enthusiastic friends in other cold regions exaggerated more or less the same. But reality was a different matter...

What norwegian considers zone 8 a little further away from his place is probably only 7b. And I guess the best, most unique and sheltered spots over there are 8b.

Come on guys, do you realize? 8b at this latitude, it's already unique in the world and there's no need to overdraw really.

However, you are quite right Axel in pointing out that a good USDA zone is not enough to determine what you can grow: with such little summer heat (average minimum for the warmest month is 11°C / 51°F and average maximum is only 16°C / 60°F !), there is a clear limit. But still, I have always admire this part of the world for its unbelievable mild climate regarding its latitude.

The site I used is actually a neutral weather data cruncher. It takes the data straight and turns it into a report. Since the Wikipedia page has no citation, I trust the data more than Wikipedia. There are spots on the Norwegian coast that are indeed 9b, and the Irish Coastline even features USDA 10a. But, as many have already pointed out, a USDA zone means little when it comes to growing stuff.

I'm sure the site you mention is neutral and has reliable data (they actually correspond to the national official data). What I meant concerned the interpretation one can make of the following sentence:

"Over the course of a year, the temperature typically varies from 33°F to 61°F and is rarely below 26°F or above 68°F. "

We are not talking about the average annual minimum (which is what is taken into account for the USDA zones), but about, first, the average minimum temp of the coldest moth and second the average max temp of the warmest month.

For example, it corresponds to the 46°F to 70°F range of San Francisco, Ca.

If 46°F was the min temp to take into account for USDA zones, then San Francisco would be 11b...

Second, what does "rarely below 26°F" mean? What is rare? The data I gave you are just as reliable, but here they are again: "they've already hit -6°C (21°F) this year, hit -13°C (8°F) last year, -9°C (16°F) in 2011, -8°C (17,5°F) in 2010, -10°C (14°F) in 2006, etc."

26°F is not their worst temp then, only a limit they just occasionally / rarely brake.

"Rare" may simply mean that only once or twice a year the thermometer goes below 26°F. For the official administrations in charge of weather in Europe, "rare" is usually for "a phenomenon which happens less than 3 days a year". For a phenomenon which happens less than once a year, it is usually called then "very rare" and if it's only once per decades, it is called "exceptional".

But a place with such data is cooler than a USDA 9b...

Nevertheless, even 8b bordering to 9a is simply amazing, awe-inspiring at such a (nearly polar) latitude!!!

"We are not talking about the average annual minimum (which is what is taken into account for the USDA zones)" - Sorry, but that statement is false The average annual minimum has little to do with the USDA zone. The USDA zone is based on the extreme minimum averaged over many years. For Ålesund that number appears to be 26F as the data suggests.

All the data I've been able to find on Ålesund shows no lows below 26F. Show me the data and then I will believe you. The web page you quoted has no data on Ålesund, so I am curious to know where you find your data. I think you are confusing two different locations with similar names. The one I am talking about is http://www.wunderground.com/weather-forecast/NO/Alesund.html, the one you are probably thinking of is http://www.wunderground.com/weather-forecast/NO/Ny_Alesund.html. These are two different places.

Can you also show the data about the rhopies dying in Tresco? I've not seen any references on that either. 19F didn't kill all rhopies in Northern California in the 1990 freeze, I would be surprised if they did in Tresco.

[Xenon]

Weather data for Alesund Airport (ENAL): http://www.wunderground.com/history/airport/ENAL/2013/12/25/MonthlyHistory.html

Last five years have all dropped below 25*F

Search "rhopalostylis tresco", should bring up 3 threads

Edited December 25, 2013 by Xenon

[Jose Maria]

Interesting and unbelievable this Norwegian garden!

I was camping in Norway many years ago, and I certainly remember the cold, even when it was summertime.

Just an unbelievably beautiful garden. Puts many of us in the tropics ...longing for something like this.

How many gardeners to take care of this garden? And I see no weeds, maybe too cold for weeds!

I imagine some of those plants get sheltered in a greenhouse during winter...?

[stygiana]

Thanks Xenon for being a meticulous observer.

Axel, I did not make such a silly confusion as to mistake Ålesund with Ny-Ålesund, the later being in Svalbard!!! And if you imagined my data were for Svalbard, then I'm not the one who's mixed up!!!

And here are the links, my friend:

December 2013:

http://www.wunderground.com/history/airport/ENAL/2013/12/25/MonthlyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Min is -6°C indeed (21°F).

December 2012:

http://www.wunderground.com/history/airport/ENAL/2012/12/25/MonthlyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Min is -13°C (8,6°F).

March 2006:

http://www.wunderground.com/history/airport/ENAL/2006/3/1/MonthlyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Min is -10°C (14°F).

Last but not least, again, I am very sorry if my English wasn't right when you say: (concerning my sentence"We are not talking about the average annual minimum (which is what is taken into account for the USDA zones)") "Sorry, but that statement is false The average annual minimum has little to do with the USDA zone. The USDA zone is based on the extreme minimum averaged over many years."

I actually meant what you are calling "extreme minimum averaged over many years". That's exactly what I meant, and the data I used are exactly this, nothing else.

I calculated the extreme average following the USDA standard, only difference being that it was over the last ten years. It gave me 19,8°F for Ålesund (and not Ny-Alesund, please) for the last ten years as mentioned before.

And once again, calculating over a longer period of time may not have given much higher number for the reasons mentioned in my former post.

I just calculated official data, nothing else.

Sorry if I said "average annual minimum", I just shortened "average annual extreme minimum" and copied this term from these sources (one of which actually says simply "average annual min" as I copied it):

[stygiana]

I will go to bed now, but after more research, I think the data I mentioned above are correct. With an extreme average low of nearly 20°F one can say that there is near Ålesund the only USDA 9a zones in Scandinavia. The Faroe islands are more or less identical, which is crazy as they are not near the mainland (I would have bet the Faroe were much milder than any place in Norway). I guess the mountain range which separates Norway from Sweden protects the coast from cold snaps coming from Northern Russia (East to West). There's only North to South waves left as possible cold snaps, but as they pass above unfrozen ocean (and then warm up), they cannot be as cold as they're supposed to be for this latitude.

Thank you Axel, I until today believed there was only zone 8, maybe barely 8b at best in the most favoured spots in Norway, now I know there are a few tiny pockets in zone 9a, near Ålesund.

Zone 9 in Norway, that's mad...

That's what I call making knowledge progress or spread. It is sometimes achieved through bumper cars and may take a few rows, but in the end it's just good.

Merry Christmas!

[Mauna Kea Cloudforest]

Thanks Xenon for being a meticulous observer.

Axel, I did not make such a silly confusion as to mistake Ålesund with Ny-Alesund, the later being in Svalbard!!! And if you imagined my data were for Svalbard, then I'm not the one who's mixed up!!!

And here are the links, my friend:

December 2013:

http://www.wunderground.com/history/airport/ENAL/2013/12/25/MonthlyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Min is -6°C indeed (21°F).

December 2012:

http://www.wunderground.com/history/airport/ENAL/2012/12/25/MonthlyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Min is -13°C (8,6°F).

March 2006:

http://www.wunderground.com/history/airport/ENAL/2006/3/1/MonthlyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Min is -10°C (14°F).

Last but not least, again, I am very sorry if my English wasn't right when you say: (concerning my sentence"We are not talking about the average annual minimum (which is what is taken into account for the USDA zones)") "Sorry, but that statement is false The average annual minimum has little to do with the USDA zone. The USDA zone is based on the extreme minimum averaged over many years."

I actually meant what you are calling "extreme minimum averaged over many years". That's exactly what I meant, and the data I used are exactly this, nothing else.

I calculated the extreme average over ten years following the USDA standard. It gave me 19,8°F for Ålesund (and not Ny-Alesund, please) for the last ten years as mentioned before.

And once again, calculating over a longer period of time may not have given much higher number for the reasons mentioned above.

And 26°F is surely not the long range record for this place.

I just calculated official data, nothing else.

Sorry if I said "average annual minimum", I just shortened "average annual extreme minimum" and copied this term from these sources (one of which actually says simply "average annual min" as I copied it):

The website reference I had posted claims to include 2012, and even with 2012, it claims that the average extreme low is 26F. To check if this is right, I pulled a few years just to see. You're right, tt doesn't jive. According to the data on Wunderground, the extreme average is 21.2F, so barely 9a, plus the record lowest daytime high is 17F. Freezes routinely last more than a week where temps do not rebound above freezing at anytime during the day. Looking up the 2001 event, it was below freezing for almost two weeks straight with over 48 hours below 20F. I don't think a trachy would survive that kind of cold.

1996: lowest max: 26F lowest min: 26F

1997: lowest max: 28F lowest min: 23F

1998: lowest max: 28F lowest min: 24F

1999: lowest max: 30F lowest min: 24F

2000: lowest max: 28F lowest min: 23F

2000: lowest max: 28F lowest min: 23F

2001: lowest max: 17F, lowest min: 14F

2002: lowest max: 26F, lowest min: 24F

2003: lowest max: 21F, lowest min: 19F

2004: lowest max: 32F, lowest min: 28F

2005: lowest max: 28F, lowest min: 24F

2006: lowest max: 26F, lowest min: 14F

2007: lowest max: 24F, lowest min: 19F

2008: lowest max: 30F, lowest min: 24F

2009: lowest max: 30F, lowest min: 26F

2010: lowest max: 21F, lowest min: 17F

2011: lowest max: 30F, lowest min: 23F

2012: lowest max: 26F, lowest min: 8F

Tresco, on the other hand, does come up with much better numbers that are true 10a without any below freezing daytime temperatures.

1996: lowest max: 35F, lowest min: 34F

1997: lowest max: 33F, lowest min: 30F

1998: lowest max: 41F, lowest min: 39F

1999: lowest max: 41F, lowest min: 35F

2000: lowest max: 32F, lowest min: 28F (looks like bogus data)

2001: lowest max: 39F, lowest min: 37F

2002: lowest max: 39F, lowest min: 37F

2003: lowest max: 41F, lowest min: 33F

2004: lowest max: 41F, lowest min: 39F

2005: lowest max: 39F, lowest min: 33F

2006: lowest max: 39F, lowest min: 37F

2007: lowest max: 42F, lowest min: 37F

2008: lowest max: 44F, lowest min: 41F

2009: lowest max: 35F, lowest min: 32F

2010: lowest max: 37F, lowest min: 35F

2011: lowest max: 37F, lowest min: 35F

2012: lowest max: 39F, lowest min: 33F

As for the extremes in Tresco, the only thing I was able to find on Palmtalk is this:

"Rhopalostylis sapida has been grown on Tresco, Isles of Scilly at 49 degrees north (zone 10a), since the mid-nineteenth century. Although century-old trees were killed by a freak frost of -8c in 1987, their replacements are already a good size. Some coastal areas of Ireland are even milder than Tresco, and have never gone below -4c. " See http://www.palmtalk.org/forum/index.php?/topic/15492-palm-latitude-extremes/

The freak freeze of 1990 also took out quite a number of 9b and 10a trees all over Central and Northern California, heck that freeze even killed native plants. That happens in the best of 9b and 10a climates, they're not bullet proof, that much we know.

My conclusion: Tresco and the mild parts of Ireland are definitely true 10a zones. However, Ålesund Norway is a cold 9a with extended periods below freezing that will take out even an unprotected trachycarpus, so not a palm zone in my book.

[Axel Amsterdam]

I only know of one garden with a rhopy in S-Ireland. Tresco indeed lost all rhopies during an exceptional freeze (don't know the date, but the story has been confirmed numerous times on UK palm fora)

The irish coastal garden is featured in this link and it seems to be 10A

http://growingontheedge.net/viewtopic.php?f=2&t=8495

Edited December 25, 2013 by Axel Amsterdam

[stygiana]

Can you also show the data about the rhopies dying in Tresco? I've not seen any references on that either. 19F didn't kill all rhopies in Northern California in the 1990 freeze, I would be surprised if they did in Tresco.

You're pretty sceptical Axel, but that's fine with me. I think all realistic, materialist and scientific approach requires scepticism (I'm a Carl Sagan fan so...).

The only issue was that I wasn't sure I would find references on the web about that (I eventually did).

In fact, I take advantage of it to give my opinion on this: if many data and information are not on the Internet, it does not mean that they do not exist.

I tell you how I knew that: I worked in NZ, at the Auckland Botanic Gardens, while the curator there was an English man, a good friend of mine since that, actually.

He knew Tresco very well, as he lived in Britain until the 80's and went there regularly, he was more than aware of the Rhopalostylis history in Tresco. The reason is evident: he was English, familiar with Tresco, familiar with Rhopies and the curator of NZ's biggest BG! And not just for that reason, I can tell you we had many talks on this subject and I perfectly remember what he said...

He is the first person who told me that they were killed, some in 1985 and then all the rest in 1987.

Then I was told the same by British palm enthusiasts in Britain and again, so I always kept it for totally clear and reliable. All those people, and Steve first (the Auckland BG's curator) were such reliable sources that it was just it.

Then you ask, today, for references. Fine. I searched, and found that:

http://www.therealgarden.co.uk/plant-directory/rhopalostylis-sapida

Have a look at the last sentences.

Concerning your statement "19F didn't kill all rhopies in Northern California in the 1990 freeze, I would be surprised if they did in Tresco.", I suggest you to read the last paragraph on that link (and enjoy the photos):

http://www.leadupthegardenpath.com/news/the-delights-of-tresco/

I saw similar events at such latitudes, in normally extremely mild places just by the sea. While the thermometer in its box indicates 15°F, all the trees are covered with ice on one side, the snow doesn't melt during the day, the day is actually very very short, and this freezer event may last for days!!!

You may record similar lows in Cali, but surely not such a (lasting) ice-doom-movie picture in the background!!!

And that can make a lot of difference!!!

[stygiana]

My conclusion: Tresco and the mild parts of Ireland are definitely true 10a zones. However, Ålesund Norway is a cold 9a with extended periods below freezing that will take out even an unprotected trachycarpus, so not a palm zone in my book.

I cannot agree more. Wanna share a Christmas beer?

[Halekuma]

Sorry I cant agree about south ireland and tresco being 10a. If A coruña has seen -3C/-4C in the 80s theres no way this places are 10a zones... One bad freezing night and those rhopies are dead... 2 decades of 10a temps dont make a place bulletproff... True cool-oceanic 10a zones are in the northern island of NZ... We are lucky to not suffer strong artic blasts since the 80s but remember that is all about cycles and our warm winter weather is quite unusual...

[Halekuma]

This is a though 9b palm for cool oceanic climates (howea forsteriana) planted as a small seedling... I have serious doubts that people at tresco can even get a kentia to that size from small seedling between the eventual artic blasts (no way above -6C at that latitude)

[Mauna Kea Cloudforest]

This is a though 9b palm for cool oceanic climates (howea forsteriana) planted as a small seedling... I have serious doubts that people at tresco can even get a kentia to that size from small seedling between the eventual artic blasts (no way above -6C at that latitude)

You're mistaken about Tresco and Southern Ireland, they are indeed USDA 10a. And you're missing the whole point of the discussion, there are more factors than just a USDA zone designation that determines what can grow. Because of the far Northern latitude of Tresco, if there is a freak deviation from the norm, it's the duration and intensity of the cold that kills the plants.

As an added note, Jeff in Modesto has a zone 9b garden just like Santa Cruz is zone 9b. Both places have very similar all time lows. The main difference is that near the coast, the intensity and duration of the cold is much less thanks to the proximity of the ocean.

The notes on the Tresco freak cold in 1987 are interesting and illustrate the extreme nature of the freak cold event, an event likely to occur only once or twice per century.

In January 1987 a snowstorm brought temperatures down to -8c, made worse by a 25 knot easterly wind , with the wind chill factor it felt -25c. The snow lasted 15 days but the temperatures stayed the same for some time. They say the garden literally fell to pieces and collapsed into oblivion. The Botanic Gardens around the world came to their rescue and plants and seeds came from far and wide, gardeners the world over are very generous and share what they can when one of their friends is in trouble.

[Alex High]

On 12/24/2013 at 11:10 PM, Brahea Axel said:

Can you guess where the largest, oldest most Northerly palm tree is located?

Take a look at the statistics for this canary date palm in the picture below:

Location: Fota Arboretum, Fota, Co. Cork, Ireland
Latitude: 51.8972° N (Same latitude as Alaska, sun angle is 13 degrees at Winter solstice)
Date Planted: 1896 (117 years old)
Height: 9 m
Girth: 1.55 m

(http://www.treecouncil.ie/heritagetrees/440.htm)

I have some sad news - that magnificent Phoenix canariensis is dead. I saw a picture of the just the dead trunk on Google Maps and also found another picture of it with the dead crown online. I will put the pictures below. Sorry to deliver the news and I hope the garden plants a new Phoenix canariensis in its place. They do have plenty of other nice palms, including the Chamaerops seen below!

Photo of dead crown:

Photo of dead trunk:

[Albey]

On 12/25/2013 at 6:11 PM, Tassie_Troy1971 said:

" Any idea where the most southerly palm is located? "

Dont know but New Zealand and South America some where i guess . I have 40 species outdoors @ 42.5 deg south

Hi Troy - Rhopalostylis growing at "BLUFF" Invercargill at 46.59°S