Northern Limit of Phoenix Canariensis Growth In Europe

[sped94]

Hi everyone,
I'm really interested in understanding the cold tolerance of Phoenix Canariensis in Europe. Would anyone be able to draw (or describe) a line on a map showing the northernmost boundary where this species can survive outside with little Or with no winter protection?

[Marco67]

Something like this perhaps. 

[sped94]

1 hour ago, Marco67 said:

Something like this perhaps. 

Thanks!

I do have some doubts about central Spain, places like Madrid, for example. I would expect it to be too cold in winter for Phoenix Canariensis to grow there. And of course, the Pyrenees would be out of the question.

I mostly agree with the limit you've drawn for Italy. I live in the northern Adriatic area, and I can confirm that it's really the edge of what this palm can tolerate.

Personally, I might have included all of Greece, even Thessaloniki are, but I’m not very familiar with the local climate there, so I could be wrong.

[Josh76]

I could be mistaken, but I'm sure there are several mature specimens of P. canariensis in Madrid

[Josh76]

Here's a mature specimen, although the image is from 2017...

 

https://maps.app.goo.gl/4LX8dCU1qFo1MzvaA

[Josh76]

A better example, this one from 2021:

 

https://maps.app.goo.gl/WRHHSXGmip1tkg1e7

[sped94]

2 minutes ago, Josh76 said:

A better example, this one from 2021:

 

https://maps.app.goo.gl/WRHHSXGmip1tkg1e7

Very Nice one! 🙂

[SeanK]

I once saw one on Hogan's Heroes. It was visible over the barracks across from the Komandant's office. I guess they grow 🌴 in central Germany, too.

[NC-Key-Bar]

There are quite a few well documented ones around London. I’m sure some of the UK members could share specifics. 
 

 

[sped94]

8 hours ago, SeanK said:

I once saw one on Hogan's Heroes. It was visible over the barracks across from the Komandant's office. I guess they grow 🌴 in central Germany, too.

I don't think CIDP can grow in central Germany without protection. There might be some very sheltered microclimates or short-term success, but in general I belive it is not possible...

[UK_Palms]

17 hours ago, Marco67 said:

Something like this perhaps. 

The range is much larger than shown. CIDP are present in all coastal areas of England, Wales and Ireland nowadays. Large specimens can be found in Liverpool and Dublin nowadays. They are also present on the northern coast of France right up to Calais.

All of the areas with red lines have CIDP present for 10+ years and not dying.

 

I am at work now but will post more later. As I said, there are 20-25 foot specimens in places like Dublin and Liverpool nowadays that survived the brutal 2010 winter when they were much smaller. There are no CIDP documented in Scotland however. The furthest north ones are around Blythe just above Newcastle at 55N.

I am basing the CIDP survival range on following…

• Specimens must survive there for at least 10 years
• Specimens must be actively growing and not declining
• Specimen's must not rely on any winter protection

[sped94]

so we can say something like this:

 

[Axel Amsterdam]

This one has been growing in the area of Schiphol Amsterdam airport sinds 2016, unprotected. Picture from January

[Axel Amsterdam]

Same palm in 2016 and 2019 (recovering from cold 2018)

[SeanK]

14 hours ago, sped94 said:

I don't think CIDP can grow in central Germany without protection. There might be some very sheltered microclimates or short-term success, but in general I belive it is not possible...

I believe you. My post was meant as a joke for the Americans.

[coconut2024]

I have one planted in southeastern Slovenia, Usda zone 8a, but winters milder than that. It's my first year but my neigbour had one in her garden for 3 years and she lost the palm because of a fungal disease. But they need protection!! 

[sped94]

15 hours ago, Axel Amsterdam said:

Same palm in 2016 and 2019 (recovering from cold 2018)

Thank you for you input!

But in your opinion, can we consider this an isolated case thanks to the sheltered location and a particularly favorable microclimate? Or is it the norm?

[sped94]

1 hour ago, coconut2024 said:

I have one planted in southeastern Slovenia, Usda zone 8a, but winters milder than that. It's my first year but my neigbour had one in her garden for 3 years and she lost the palm because of a fungal disease. But they need protection!! 

Thank You, i hope your CIPD will survive the next winters 🙂

[Axel Amsterdam]

2 hours ago, sped94 said:

Thank you for you input!

But in your opinion, can we consider this an isolated case thanks to the sheltered location and a particularly favorable microclimate? Or is it the norm?

certainly not the norm. It really is all about microclimates, stone and wall environments and/or proximity to bodies of water. 

[Marco67]

On 7/15/2025 at 2:27 PM, sped94 said:

so we can say something like this:

 

I think that is being a bit opstimi

 

On 7/15/2025 at 2:27 PM, sped94 said:

so we can say something like this:

 

Everyone is entitled to his opinion of course, but I am thinking this map is a bit too optimistic. I don't see Canariensis surviving long-term outside certain coastal places of Ireland or England. Only in bigger cities do they have a better chance. Even just outside of London, they die eventually.

I am a bit in doubt about Southern France just north of the Pyrenees. I have seen some photos of people growing Canariensis but I am not sure if they survive long-term there. With protection this line moves north, but then you might as well include the Netherlands. I was thinking more of the map below. 

 

[UK_Palms]

The CIDP range is pretty wide for the UK as evidenced by this one in Leeds, which is up north and quite far inland, but has never been protected. Growth is slow, but it survives and rarely gets damaged.

2014 street view…

 

2024 street view (10 years later)…

The red marker is the location and it is about 57 miles inland from the coast there…

 

So CIDP can potentially survive at 60 miles inland from the coast in England and at 54N, with the help of some UHI from a city.

Along the immediate coastline, they can survive up to 55N in England and Northern Ireland. This has been documented quite well now. @Marco67

[Axel Amsterdam]

A couple of large CIDP’s in Paris too, in microclimates (like this one sticking over a very high wall at jardin des plantes)). Also quite a nr of dactylifera doing well in Paris. 

[Marco67]

5 hours ago, UK_Palms said:

The CIDP range is pretty wide for the UK as evidenced by this one in Leeds, which is up north and quite far inland, but has never been protected. Growth is slow, but it survives and rarely gets damaged.

2014 street view…

 

2024 street view (10 years later)…

The red marker is the location and it is about 57 miles inland from the coast there…

 

So CIDP can potentially survive at 60 miles inland from the coast in England and at 54N, with the help of some UHI from a city.

Along the immediate coastline, they can survive up to 55N in England and Northern Ireland. This has been documented quite well now. @Marco67

It's not always purely cold which puts a limit on what you can grow but more a combination of different factors like how wet it gets in the winter, how long the frost period lasts, how long the growing season is, the soil type, etc.

Especially in the north, palms die often from rot caused by wet cold. Although it doesn't get very cold in certain places, palms don't thrive and might eventually die there. We don't have lot of heat to compensate for it unfortunately.

But I agree a microclimate can do miracles and palms can survive and even do well in very unexpected places.

[Axel Amsterdam]

1 hour ago, Marco67 said:

It's not always purely cold which puts a limit on what you can grow but more a combination of different factors like how wet it gets in the winter, how long the frost period lasts, how long the growing season is, the soil type, etc.

Especially in the north, palms die often from rot caused by wet cold. Although it doesn't get very cold in certain places, palms don't thrive and might eventually die there. We don't have lot of heat to compensate for it unfortunately.

But I agree a microclimate can do miracles and palms can survive and even do well in very unexpected places.

Marco, this is not true for CIDP’s in milder locations with frosts of around -6C occasionally (and daytemps of around/above 0C). CIDP’s will easily survive this also if it rains for months during winter followed by a bad spring without heat.

It’s about the mild minimum temps and nothing else, as can be distracted from the avalilable data on CIDP’s on the rainy coasts of Brittany and the UK all the way op to York.  

[Marco67]

I disagree with you. The reason you don't see Canariensis in places like western Scotland or Norway which have very mild winters, is that there is hardly any heat and lots of rain. Because of the lack of heat, Canariensis will hardly grow and will become weaker over the years. It will go in decline and eventually die because of rot.

You need a certain amount of heat for Canariensis to grow properly. It might need less heat than dactylifera, but it still needs some heat to grow. The only palm species that can cope with these conditions is Trachcycarpus.

[UK_Palms]

I see my post above is screwed up with images not displaying. I will ask @PALM MOD to remove the post above. ☝️

In the meantime, here is the breakdown of most northern CIDP's in the UK. The furthest ones from the equator in the world. Street view cannot keep up with the growth of some of these...

Dublin, Ireland at 53N...

 

Plenty of CIDPs on the north coast of Wales. As mentioned previously, they are present along the entire coastline of Wales, but this is just the ones in northern Wales...

 

Here's the one near Liverpool at 53.42N latitude. It is getting pretty big now and has maybe been growing there for 20 years. This is at the same latitude as Edmonton in Canada.

 

Obviously there is the Leeds one I mentioned, which is particularly impressive when you consider it is 57 miles inland at 53.48N.

 

Morecambe at 54.04N latitude...

 

The Scarborough one (54.3N lat) has been there about 20 years and survived the awful 2010 winter freeze while tiny. So it is definitely long term and fully hardy there, especially now that it is much bigger. This one has actually flowered there as well...

 

Quite a few CIDP's around Redcar at 54,6N lat...  remember a lot of the ones in London looked like this in the 2000's...

 

South Shields, Newcastle at 55N...

 

I might as well post these CIDPs in southwest Scotland too at 54.7N. Certainly the most promising Scottish planting that I have seen, right by the coast with plenty of sun. They have clearly grown with screenshots showing them in 2016 and again in 2023 after the very cold 2022/23 winter, which took out a lot of my exotics. Yet these CIDP survived that winter in this Scottish microclimate. So this is a highly favourable spot by Scotland's standards. I suspect these will get to a relatively good size over time... 🏴󠁧󠁢󠁳󠁣󠁴󠁿

 

 

This would have been one of the furthest north ons at 55.02N but it appears to have been cut down sometime in 2023 or 2024 unfortunately. It had clearly grown quite a lot since the 2012 street view image and was last visible in 2023, having survived the 22/23 winter fine, before then getting chopped down...

 

Ballymena, Northern Ireland at 55.03N latitude appears to be the furthest north one I can see. Planted tiny about 16-17 years ago. Same latitude as the southern parts of Alaska. This CIDP is also a bit further north than the ones above in southwest Scotland. 2009 vs 2021 growth shown... (this will be bigger when it next updates again)...

It survived the coldest December on record (2010) and there are 12 years between the street view images. It has not gone into decline and has actually grown a fair bit given the 55N latitude. Therefore it does appear to be long term there on the north coast of Northern Ireland, based on it's evident growth, relative good health and the fact it survived the 2010 event while tiny.

 

*disclaimer - these are the furthest north ones I have now seen in New Hartley at 55.5N but they are not established yet. I will track them over the next few years however...

 

@Marco67 Also these are just the documented specimens that I know about. There are probably many more planted out there, maybe even further north than the ones shown here. But I agree that southwest Scotland is the absolute limit really as they require a certain amount of summer warmth and sunshine hours in order to survive and not go into decline. @gurugu

[Axel Amsterdam]

On 7/17/2025 at 11:02 PM, Marco67 said:

I disagree with you. The reason you don't see Canariensis in places like western Scotland or Norway which have very mild winters, is that there is hardly any heat and lots of rain. Because of the lack of heat, Canariensis will hardly grow and will become weaker over the years. It will go in decline and eventually die because of rot.

You need a certain amount of heat for Canariensis to grow properly. It might need less heat than dactylifera, but it still needs some heat to grow. The only palm species that can cope with these conditions is Trachcycarpus.

Marco, i was actually referring to your rather conservative mapping of CIDP’s in the UK. But now that we have seen pictures of actual CIDP’s in western Schotland i think it’s fair to also keep an open mind to western Norway as well. Let the experts inform us (and streetview data) instead of assumptions about CIDP requirements for heat. After all, when winter temps are mild (up to -6C) the CIDP doesnt need to recover in spring and also starts growing earlier in the season. CIDP’s keep growing during winter in London and south coastal UK as well and these winterdays are not 18C (cool summer temps in Norway) and also there are no bright light conditions. CIDP’s are misunderstood by people from wintercold areas. They think CIDP’s need heat because they are from the canaries, but they only need heat if they have to recover from a cold Dutch/ inland UK winter. 

 

No

[gurugu]

19 hours ago, UK_Palms said:

I see my post above is screwed up with images not displaying. I will ask @PALM MOD to remove the post above. ☝️

In the meantime, here is the breakdown of most northern CIDP's in the UK. The furthest ones from the equator in the world. Street view cannot keep up with the growth of some of these...

Dublin, Ireland at 53N...

 

Plenty of CIDPs on the north coast of Wales. As mentioned previously, they are present along the entire coastline of Wales, but this is just the ones in northern Wales...

 

Here's the one near Liverpool at 53.42N latitude. It is getting pretty big now and has maybe been growing there for 20 years. This is at the same latitude as Edmonton in Canada.

 

Obviously there is the Leeds one I mentioned, which is particularly impressive when you consider it is 57 miles inland at 53.48N.

 

Morecambe at 54.04N latitude...

 

The Scarborough one (54.3N lat) has been there about 20 years and survived the awful 2010 winter freeze while tiny. So it is definitely long term and fully hardy there, especially now that it is much bigger. This one has actually flowered there as well...

 

Quite a few CIDP's around Redcar at 54,6N lat...  remember a lot of the ones in London looked like this in the 2000's...

 

South Shields, Newcastle at 55N...

 

I might as well post these CIDPs in southwest Scotland too at 54.7N. Certainly the most promising Scottish planting that I have seen, right by the coast with plenty of sun. They have clearly grown with screenshots showing them in 2016 and again in 2023 after the very cold 2022/23 winter, which took out a lot of my exotics. Yet these CIDP survived that winter in this Scottish microclimate. So this is a highly favourable spot by Scotland's standards. I suspect these will get to a relatively good size over time... 🏴󠁧󠁢󠁳󠁣󠁴󠁿

 

 

This would have been one of the furthest north ons at 55.02N but it appears to have been cut down sometime in 2023 or 2024 unfortunately. It had clearly grown quite a lot since the 2012 street view image and was last visible in 2023, having survived the 22/23 winter fine, before then getting chopped down...

 

Ballymena, Northern Ireland at 55.03N latitude appears to be the furthest north one I can see. Planted tiny about 16-17 years ago. Same latitude as the southern parts of Alaska. This CIDP is also a bit further north than the ones above in southwest Scotland. 2009 vs 2021 growth shown... (this will be bigger when it next updates again)...

It survived the coldest December on record (2010) and there are 12 years between the street view images. It has not gone into decline and has actually grown a fair bit given the 55N latitude. Therefore it does appear to be long term there on the north coast of Northern Ireland, based on it's evident growth, relative good health and the fact it survived the 2010 event while tiny.

 

*disclaimer - these are the furthest north ones I have now seen in New Hartley at 55.5N but they are not established yet. I will track them over the next few years however...

 

@Marco67 Also these are just the documented specimens that I know about. There are probably many more planted out there, maybe even further north than the ones shown here. But I agree that southwest Scotland is the absolute limit really as they require a certain amount of summer warmth and sunshine hours in order to survive and not go into decline. @gurugu

Absolutely stunning seeing Phoenix at 55⁰N. and even further north.

Speechless about the information and files you give.👍

[Marco67]

22 hours ago, Axel Amsterdam said:

Marco, i was actually referring to your rather conservative mapping of CIDP’s in the UK. But now that we have seen pictures of actual CIDP’s in western Schotland i think it’s fair to also keep an open mind to western Norway as well. Let the experts inform us (and streetview data) instead of assumptions about CIDP requirements for heat. After all, when winter temps are mild (up to -6C) the CIDP doesnt need to recover in spring and also starts growing earlier in the season. CIDP’s keep growing during winter in London and south coastal UK as well and these winterdays are not 18C (cool summer temps in Norway) and also there are no bright light conditions. CIDP’s are misunderstood by people from wintercold areas. They think CIDP’s need heat because they are from the canaries, but they only need heat if they have to recover from a cold Dutch/ inland UK winter. 

 

No

In my opinion, in order to grow Canariensis successfully and many other exotics in that respect, depends on a range of factors instead of only the minimum temperatures. Things like the amount of rainfall, soil type, hours of sunshine, spring/summer heat, and many more elements play a role in their successful long-term survival. I'll stick to that opinion.

The one in the photos from Scotland doesn't look too great in my opinion, with the leaves being a bit yellowish. Besides, I don't know when these were planted and if they are protected during the winter. Most of these photos were also either taken on the coast or in sheltered locations in cities.

Even in a zone 9a climate, temperatures can dip below -6°C sometimes; it's not some kind of holy minimum value for that zone. To have a good chance for growing a Canarienis in our cool, wet, northerly climate, you probably need to be in a 9a/9b zone.

I found this clip from someone growing exotics in Norway. It seems his Canariensis took quite some damage last winter. 

 

[UK_Palms]

New rule - if you cannot grow Echium Pininana to flower without providing winter protection, you cannot grow CIDP either.

I have lost every Echium I have ever tried growing here. Even during a mild winter, they get knocked out by the odd night of -4C or -5C. Yet a quick scan around that part of Scotland with the CIDP's shows some fantastic looking Echium Pininana nearby, which appear to be self seeding even. So that is why the CIDP's are surviving there, because it clearly doesn't drop below about -3C really most winters. Otherwise you wouldn't be seeing Echium like this in that part of Scotland. Both CIDP and Echium Pininana are endemic to the Canary Islands and grow side by side each other. 

Drummore, Scotland...

 

Echium Candicans (native to Medeira)

 

Echium Pininana takes 12-24 months to flower after germination, so they will need to survive 1-2 winters to reach flower. So that is 2 out of every 3 winters not going below -3C or -4C. If it is too cold for Echium Pininana, it is going to be too cold for CIDP. I know bigger CIDP's can take -10C and defoliate but come back still, even here in the UK, but you are simply not going to get a smaller CIDP established if you are having -5C or lower every winter. It will just get knocked back every winter and go into decline. As Axel mentioned, if a smaller CIDP is having to recover each spring/summer and replenish damaged growth, it won't really grow at all, as opposed to it continuously growing year-round and not getting knocked back each winter. I have had this issue myself here.

You really need most winters to not go below about -3C or -4C at street level, allowing them to get established and grow to a decent size. Once much bigger and properly established, they can survive -10C and a total defoliation if it only happens say once a decade. But they would need to be pretty big and established at that point before they are subjected to anything below -7C. So basically 2 out of 3 winters cannot drop below -4C really and 1 in 3 winters cannot go below -7C, which is the threshold for spear pulls in our climate. This is absolutely crucial to getting them established. Once they are established, big enough and flowering, with more recovery capabilities, they can withstand a freak once a decade winter of -8C to -10C in our northern locations. But back to back defoliations in consecutive winters (-5C for smaller ones and -8C for bigger ones) will lead to serious decline and failure. I know this because I am outside of London's UHI and I cannot grow them here. -8C in December 2022 defoliated my smaller one, which started regrowing slowly, only for it to be finished off by one night of -6C in January 2025.

 

3 minutes ago, Marco67 said:

The one in the photos from Scotland doesn't look too great in my opinion, with the leaves being a bit yellowish. Besides, I don't know when these were planted and if they are protected during the winter.

You can see in the first screenshot that they were planted around 2015-2016 and the second screenshot is from 2023, showing a reasonable amount of growth for almost 55N. I seriously doubt those Scottish CIDP get any protection there, especially since it doesn't even get cold enough. You talk about them being 'yellowish', but you also have to consider that the most recent street view images that I posted were from June 2023, right after the freezing cold 22/23 winter as well. That was a winter that knocked out my CIDP here in southern England, although I am quite far inland with no UHI. Yet those Scottish ones survived the 22/23 winter up there and don't even look too bad. Plus they are still small and getting established. We will see how they look in a few years!

I am not sure Alesund (the mildest part of Scandinavia in winter) can have flowering Echium Pininana that are not protected over winter, never mind CIDP that are actively growing year on year, without any protection. As well as most winters not going below -3C or -4C, I think CIDP also need AT LEAST 150 hours of sunshine in winter too. Stranraer in southwest Scotland gets 190 hours in winter vs 100 hours in Alesund, Norway. That is actually a staggering difference. London gets 205 hours in winter for comparison. More than double Alesund's winter sunshine hours. This is going to be a massive factor as well, in terms of daytime recovery during freeze events and keeping the palm in growth and healthy. The sunshine hours should not be overlooked in my opinion.

 

3 hours ago, Marco67 said:

Most of these photos were also either taken on the coast or in sheltered locations in cities.

I'm not sure what your argument/point here is because pretty much all of the CIDP in the UK are in coastal areas or towns/cities with UHI. Even in parts of Cornwall, there are huge CIDP's along the coast, but if you go a few miles inland to higher elevation and in the countryside with no UHI, you wouldn't stand a chance. Plymouth in Devon which is right on the coast might only see -2C or -3C on a very cold night in winter, but go 5 miles inland around Dartmoor National Park and they could easily get -8C there. That is the difference between no damage on CIDP whatsoever and total defoliation. It should be already known that there aren't any inland CIDP's out in the rural countryside with no UHI in the UK. My location is proof of that. You need coastal proximity or an UHI.

I would hedge a bet that the Isle of Arran probably has some CIDP's on the south coast of the island, but street view has not updated in 16 years there, so it is pointless looking.

[Axel Amsterdam]

10 hours ago, Marco67 said:

In my opinion, in order to grow Canariensis successfully and many other exotics in that respect, depends on a range of factors instead of only the minimum temperatures. Things like the amount of rainfall, soil type, hours of sunshine, spring/summer heat, and many more elements play a role in their successful long-term survival. I'll stick to that opinion.

The one in the photos from Scotland doesn't look too great in my opinion, with the leaves being a bit yellowish. Besides, I don't know when these were planted and if they are protected during the winter. Most of these photos were also either taken on the coast or in sheltered locations in cities.

Even in a zone 9a climate, temperatures can dip below -6°C sometimes; it's not some kind of holy minimum value for that zone. To have a good chance for growing a Canarienis in our cool, wet, northerly climate, you probably need to be in a 9a/9b zone.

I found this clip from someone growing exotics in Norway. It seems his Canariensis took quite some damage last winter. 

 

Marco, you are entitled to your opinion ofcourse, I never said Norway would be able to grow CIDP’s, I just keep an open mind. I know a lot of CIDP’s in the Netherlands so I am able to draw conclusions on real examples and data.

The Dutch picture largely follows UK Palms’ analysis about temperature ranges in the UK. Small CIDP’s don’t decline after a rainy -3/-4 winter and can also take it a bit colder (up to an incidental -6) without damage provided it’s not repeated and persisting. All the other factors are pretty much irrelevant in Holland although stone and a southern exposure lower the temperature threshold a bit which certainly helps survival in colder winters. This is not an opinion, i note this around Amsterdam every year. In it’s most extreme form small Dutch CIDP’s also survive colder winters (like 2018) because they were planted closely against a south wall in a city (see picture)

 

 

Now large CIDP’s can take even more, but still -7c will start damaging the fronds. But it won’t die. I know a couple of larger CIDP’s and they recovered from these temperatures without protection as can be seen from the pictures I posted above. That CIDP on the waterside has been growing unprotected for around 10 years including defoliation and is impressive for inland Holland. 

[Axel Amsterdam]

Same plants in 2014, 11 years unprotected. 

[Axel Amsterdam]

But in the end you’re far better off growing butia eriospatha in Holland. Unprotected for 10 years in Nijmegen, more than 100 km inland

[sped94]

3 hours ago, Axel Amsterdam said:

But in the end you’re far better off growing butia eriospatha in Holland. Unprotected for 10 years in Nijmegen, more than 100 km inland

Very Nice! I love Butia palms

[sped94]

This is the CIDP planted in front of my office.
It has never been protected during winter. 
 

 

[Mazat]

On 7/14/2025 at 8:02 PM, sped94 said:

 

Hi everyone,
I'm really interested in understanding the cold tolerance of Phoenix Canariensis in Europe. Would anyone be able to draw (or describe) a line on a map showing the northernmost boundary where this species can survive outside with little Or with no winter protection?

there are or would be exceptions here in Switzerland where CIDP could grow, except for southern Ticino and the rest of Ticino in microclimates.
it certainly works at Lake Walen, Quinten and Weesen. partly at Lake Geneva in sheltered locations. certainly less so at the beginning when completely unprotected. At Lake Walen, Quinten, even if it is -5.0 degrees Celsius in the morning, which is very cold for the villagers there, it can quickly reach 10 degrees Celsius at noon due to the location, certainly above zero, as the weather data has repeatedly shown.

 

[Mazat]

On 7/15/2025 at 1:01 AM, SeanK said:

I once saw one on Hogan's Heroes. It was visible over the barracks across from the Komandant's office. I guess they grow 🌴 in central Germany, too.

😁

[Mazat]

On 7/22/2025 at 12:46 AM, UK_Palms said:

New rule - if you cannot grow Echium Pininana to flower without providing winter protection, you cannot grow CIDP either.

I have lost every Echium I have ever tried growing here. Even during a mild winter, they get knocked out by the odd night of -4C or -5C. Yet a quick scan around that part of Scotland with the CIDP's shows some fantastic looking Echium Pininana nearby, which appear to be self seeding even. So that is why the CIDP's are surviving there, because it clearly doesn't drop below about -3C really most winters. Otherwise you wouldn't be seeing Echium like this in that part of Scotland. Both CIDP and Echium Pininana are endemic to the Canary Islands and grow side by side each other. 

Drummore, Scotland...

 

Echium Candicans (native to Medeira)

 

Echium Pininana takes 12-24 months to flower after germination, so they will need to survive 1-2 winters to reach flower. So that is 2 out of every 3 winters not going below -3C or -4C. If it is too cold for Echium Pininana, it is going to be too cold for CIDP. I know bigger CIDP's can take -10C and defoliate but come back still, even here in the UK, but you are simply not going to get a smaller CIDP established if you are having -5C or lower every winter. It will just get knocked back every winter and go into decline. As Axel mentioned, if a smaller CIDP is having to recover each spring/summer and replenish damaged growth, it won't really grow at all, as opposed to it continuously growing year-round and not getting knocked back each winter. I have had this issue myself here.

You really need most winters to not go below about -3C or -4C at street level, allowing them to get established and grow to a decent size. Once much bigger and properly established, they can survive -10C and a total defoliation if it only happens say once a decade. But they would need to be pretty big and established at that point before they are subjected to anything below -7C. So basically 2 out of 3 winters cannot drop below -4C really and 1 in 3 winters cannot go below -7C, which is the threshold for spear pulls in our climate. This is absolutely crucial to getting them established. Once they are established, big enough and flowering, with more recovery capabilities, they can withstand a freak once a decade winter of -8C to -10C in our northern locations. But back to back defoliations in consecutive winters (-5C for smaller ones and -8C for bigger ones) will lead to serious decline and failure. I know this because I am outside of London's UHI and I cannot grow them here. -8C in December 2022 defoliated my smaller one, which started regrowing slowly, only for it to be finished off by one night of -6C in January 2025.

 

You can see in the first screenshot that they were planted around 2015-2016 and the second screenshot is from 2023, showing a reasonable amount of growth for almost 55N. I seriously doubt those Scottish CIDP get any protection there, especially since it doesn't even get cold enough. You talk about them being 'yellowish', but you also have to consider that the most recent street view images that I posted were from June 2023, right after the freezing cold 22/23 winter as well. That was a winter that knocked out my CIDP here in southern England, although I am quite far inland with no UHI. Yet those Scottish ones survived the 22/23 winter up there and don't even look too bad. Plus they are still small and getting established. We will see how they look in a few years!

I am not sure Alesund (the mildest part of Scandinavia in winter) can have flowering Echium Pininana that are not protected over winter, never mind CIDP that are actively growing year on year, without any protection. As well as most winters not going below -3C or -4C, I think CIDP also need AT LEAST 150 hours of sunshine in winter too. Stranraer in southwest Scotland gets 190 hours in winter vs 100 hours in Alesund, Norway. That is actually a staggering difference. London gets 205 hours in winter for comparison. More than double Alesund's winter sunshine hours. This is going to be a massive factor as well, in terms of daytime recovery during freeze events and keeping the palm in growth and healthy. The sunshine hours should not be overlooked in my opinion.

 

I'm not sure what your argument/point here is because pretty much all of the CIDP in the UK are in coastal areas or towns/cities with UHI. Even in parts of Cornwall, there are huge CIDP's along the coast, but if you go a few miles inland to higher elevation and in the countryside with no UHI, you wouldn't stand a chance. Plymouth in Devon which is right on the coast might only see -2C or -3C on a very cold night in winter, but go 5 miles inland around Dartmoor National Park and they could easily get -8C there. That is the difference between no damage on CIDP whatsoever and total defoliation. It should be already known that there aren't any inland CIDP's out in the rural countryside with no UHI in the UK. My location is proof of that. You need coastal proximity or an UHI.

I would hedge a bet that the Isle of Arran probably has some CIDP's on the south coast of the island, but street view has not updated in 16 years there, so it is pointless looking.

Ben, thank you very much for the interesting explanations and information.
it is particularly interesting and exciting that if one plant cannot thrive, CIDP apparently cannot thrive in such a location either, at least not without protection.
very insightful.

[Axel Amsterdam]

2 hours ago, sped94 said:

This is the CIDP planted in front of my office.
It has never been protected during winter. 
 

 

That’s beauty. Assuming this is in Mestre I noticed that a CIDP in Padua took quite some damage/defoliation. So coastal exposure seems to be important in N Italy around the Adriatic coast too, correct?

[Axel Amsterdam]

This CIDP gets protection during winter