Jubaea or Phoenix, which one is hardier?

[MSX]

Hello everyone! I've heard from many so many sources that Jubaea chilensis is the hardiest of all pinnate palms. Lately, I've been browsing Dave's Garden, and according to it Jubaea is hardy to zone 8b, while lesser known Phoenix theophrasti is hardy to 7b. There is 1 zone difference, too much for a statistical mistake. I created a quick summary Excel chart with the hardiness info of some popular cold-hardy palms from Dave's Garden web site. And I have two questions to our comminity now - how reliable is information from Dave's Garden web site, and if choosing between Jubaea and some Phoenix species, let's say Phoenix theophrasti for example, what would be a better choice for drier/arid deep inland areas of 8a zone?

[Phoenikakias]

What is your average low during winter and under what conditions? (wet or dry cold, duration, rise of temperature afterwards). I fear that none of them is reliably cold hardy for your place. It is no coincidence that the nearest palm to your place growing naturally is the Nannorrhops ritchiana...

[MSX]

54 minutes ago, Phoenikakias said:

What is your average low during winter and under what conditions? (wet or dry cold, duration, rise of temperature afterwards). I fear that none of them is reliably cold hardy for your place. It is no coincidence that the nearest palm to your place growing naturally is the Nannorrhops ritchiana...

Thank you for your comment! The main question is not even about me and my location, I started to wonder why one popular website pushes Jubea, widely known as the hardiest of all pinnates, a way behind almost all Phoenix species, including CIDP, and Butias, and how reliable this information is.

We are in the mid of 8a USDA hardiness zone and have generally dry winters, dry springs, dry falls and super dry summers, with avg annual precipitation 185 mm, and annual humidity about 55%,  Three major palms that grow here without winter protection are Trachies, Washies and Chamaerops, but they're all fan palms. For some uknown reason I've never seen any Sabal palm, or Nannorrhops ritchiana. I was just thinking of adding some hardy pinnate palm.

Edited September 10, 2021 by MSX

[Chester B]

Your dry climate definitely helps.

Here we can grow Trachys, Butias, Jubaeas, Sabals and some Brahea but Washingtonia, Nannarrhops and Phoenix don't do well or die.  That is the consequence of a wet winter in Zone 8B.

Out this way I don't think there is a consensus which pinnate palm is hardiest - some say Butia, some say Jubaea.  I have B odorota and eriospatha as well as Jubaea and have never experienced damage with any of them so can't say from my experience.

[Phoenikakias]

19 hours ago, MSX said:

Thank you for your comment! The main question is not even about me and my location, I started to wonder why one popular website pushes Jubea, widely known as the hardiest of all pinnates, a way behind almost all Phoenix species, including CIDP, and Butias, and how reliable this information is.

We are in the mid of 8a USDA hardiness zone and have generally dry winters, dry springs, dry falls and super dry summers, with avg annual precipitation 185 mm, and annual humidity about 55%,  Three major palms that grow here without winter protection are Trachies, Washies and Chamaerops, but they're all fan palms. For some uknown reason I've never seen any Sabal palm, or Nannorrhops ritchiana. I was just thinking of adding some hardy pinnate palm.

So, where exactly is your garden located? If you can grow Chamaerops completely unprotected then Jubaea has many chances of survival and you may even try Phoenix theophrasti, at least the variety from Peloponnese or from Gölköy.

[Axel Amsterdam]

Hi Marat, from your earlier posts I understood that the robusta's in your area were unprotected and killed and the nice large filifera (picture) was passively protected. So your winters sound pretty cold. Also small chamaerops were killed in your area and bigger ones experienced severe leaf damage. Despite the very dry and sunny climate it still sounds very cold for a smaller Jubaea without protection.  But, not all climates are comparable, chamaerops is hardy here in our wet winter climate (no frond damage) but small jubaea are not hardy here (we have some very large ones that are hardy). 

[MSX]

I'm in the central lower and more desert part of Fergana valley,  it's a vast oasis in the eastern part of the country, protected by the arid mountain ranges. Yeah Axel, the Washingtonia on the picture gets ocassional winter protection, it belongs to municipality and they wrap it sometimes but not every year, not every winter, obviously every new city urban greenery manager or whoever is resposible for that at the municipality has his/her own vision on whether to protect it or not and how to protect it, but it looks good no matter what and it's cool. But, of course this is not the only Washy around, I've been to some ordinary houses of local palm growers and talked to them for some experience sharing, and most of the owners say they don't protect their Washies at all, some say they only protect them in the first or second year in the ground with a simple passive protection using reflective foam insulation rolls, but larger palms receive no protection. Here are some pics of larger specimens from local gardens. There is some craze about Washingtonia, local nurseries are full with Washies

[Axel Amsterdam]

Really goodlooking nice washies and most seem to be strongly leaning towards filifera too. 

[Axel Amsterdam]

Where are the filiferish washies in the nurseries originally coming from, Turkey? 
I noticed that the only palm growing in cold cities in Turkey, like Balikesir, are filifera’s that look very pure.

[Matt N- Dallas]

In my experience (z8b TX), Jubaea has been hardier.  I’ve lost Theophrastii three times to cold.  Jubaea has survived and grown well since 2003.  Also, had p. Dactylifera & p. Canariensis survive when Theophrastii died. I think the cold hardiness claims for Theophrastii are highly overrated- especially in wet winter locations.  

[Will]

Not growing a Jubaea yet but I also think when you can grow Chamaerops without protection and Washys also survive here and then, Jubaea should be safe to grow outside. Some people g Jubaea here in 7b with protection but it seems they have to protect washys more than Jubaea.

[kinzyjr]

Overall, I'd give the nod to Jubaea in areas where both can be grown well.  One thing that may be overlooked is that Phoenix theophrasti is a heavy clumper when mature, so if you can get one to the point where it is clustering, it might be able to come back from the root ball.  I sent a few Phoenix theophrasti seedlings to Las Cruces, NM a few years back.  It would be neat to know how they have fared there.

[MSX]

On 9/12/2021 at 12:49 PM, Axel Amsterdam said:

Where are the filiferish washies in the nurseries originally coming from, Turkey? 
I noticed that the only palm growing in cold cities in Turkey, like Balikesir, are filifera’s that look very pure.

Axel, to save on costs local nurseries buy locally grown seeds from Surkhandarya region of Uzbekistan in the extreme south of the country, there are many mature palm trees producing fruits/seeds in enough capacity to cover demand of these small local nurseries. It's difficult from distance to track where the southern mother trees originate from, they have been growing there since the 1950s when the Soviet Union opened an experimental station of southern subtropical crops with an extensive garden in Denov, and this station is providing planting material for commercial growers. I actually wanted to visit Denov, Termez and the soviet station-garden this year, I have never been there before but since it's a border area, for the moment I decided to postpone it due to the situation in the neighboring country.

Edited September 16, 2021 by MSX

[Meangreen94z]

Yeah, I think Theophrastii is a lot hardier in dry desert locations where the cold is brief,  than it is in a wet winter location. I’ve seen claims of around 0*F in the desert, but mid teens in wet conditions can do them in. Phoenix Canariensis is hardy to 0*F in wet conditions, possibly hardier in the desert. Butia Odorata is hardy to around 0*F as well in wet. Both have consistently have come back in Texas after last winter. Jubaea Chilensis is a more difficult  grow here, it may survive to 0*F in the right conditions, but the few that I’m aware of in Central or North Texas haven’t survived after last winter.

[Axel Amsterdam]

On 9/16/2021 at 6:35 PM, MSX said:

Axel, to save on costs local nurseries buy locally grown seeds from Surkhandarya region of Uzbekistan in the extreme south of the country, there are many mature palm trees producing fruits/seeds in enough capacity to cover demand of these small local nurseries. It's difficult from distance to track where the southern mother trees originate from, they have been growing there since the 1950s when the Soviet Union opened an experimental station of southern subtropical crops with an extensive garden in Denov, and this station is providing planting material for commercial growers. I actually wanted to visit Denov, Termez and the soviet station-garden this year, I have never been there before but since it's a border area, for the moment I decided to postpone it due to the situation in the neighboring country.

Interesting, are they grown grown is some climate controlled environment? Because the area seems to cold for palms judging from the pics on streetview. 

[Will]

5 hours ago, Meangreen94z said:

Yeah, I think Theophrastii is a lot hardier in dry desert locations where the cold is brief,  than it is in a wet winter location. I’ve seen claims of around 0*F in the desert, but mid teens in wet conditions can do them in. Phoenix Canariensis is hardy to 0*F in wet conditions, possibly hardier in the desert. Butia Odorata is hardy to around 0*F as well in wet. Both have consistently have come back in Texas after last winter. Jubaea Chilensis is a more difficult  grow here, it may survive to 0*F in the right conditions, but the few that I’m aware of in Central or North Texas haven’t survived after last winter.

Canariensis till 0°F? From my experience they are just hardy till 20°F. 

[UK_Palms]

16 minutes ago, Will said:

Canariensis till 0°F? From my experience they are just hardy till 20°F. 

The big ones growing in London and southern England would say otherwise. Although they haven't dealt with much below 20F, I can categorically say that 15F and 72 hours below freezing will not faze a trunking CIDP one bit. They will only take a minor bit of frond burn from those temps, assuming they are properly trunking. Size is everything when it comes to hardiness with CIDP's, as is the case with most palms. The bigger ones in London took practically zero damage from a low of 20-22F last winter, in what was an abnormally cold winter. Smaller ones may have been severely damaged or killed even, but bigger trunking specimens were practically unscathed. Even central London went down to 21-22F last winter and all the bigger CIDP's still look pristine. 

Regarding the Theophrasti vs Jubaea debate, you need to remember that Theophrasti in its native range grows in areas where the roots are almost permanently submerged in water. So in terms of wet-cold, Theophrasti is almost certainly superior. They will take quite a bit of wet-cold and come out fine, down to about 20F. Probably 10F even. My Theophrasti here took 18F in the ground fine. They are probably similar to CIDP in terms of wet-cold hardiness and their temperature limitations. However Jubaea is definitely more bud-hardy. There is evidence of Jubaea's surviving winters in parts of the UK where CIDP's and Theophrasti's have been killed off. So Jubaea's are definitely more bud-hardy than CIDP's and Theophrasti's, although there are lots of variables at stake.

The reason that Jubaea's do not survive in places like Texas and the southern USA is due to the high humidity, high rainfall and high nighttime temps during summer. Less so due the winter lows. They probably took the extreme winter lows during the February 2021 freeze in Texas, only to further succumb to the high rainfall, high humidity and high nighttime temperatures in spring/summer. All of which stressed Jubaea, combined with the extreme winter lows. Jubaea is definitely more bud-hardy in the UK though, compared to CIDP and Theophrasti. Jubaea is without a shadow of a doubt the hardier palm. Even in regards to wet-cold, at least here in the UK at 51N. 

[Meangreen94z]

1 hour ago, Will said:

Canariensis till 0°F? From my experience they are just hardy till 20°F. 

Before last February everything I had read said they were hardy to about 15*F or so(-9.4*C). They have consistently come back in Central Texas and the Dallas areas from temperatures in the -2* to 4*F (-18.9 to -15.5*C)  range in February. Not a brief cold, but 2 consecutive nights of those low temperatures and 5 days straight below freezing.

Theophrastii, Dactylifera, and  Sylvestris with a growth point above the snow/ice are all dead from those temperatures. In a wet cold Canariensis is definitively the hardiest Phoenix.

[Meangreen94z]

46 minutes ago, UK_Palms said:

The big ones growing in London and southern England would say otherwise. Although they haven't dealt with much below 20F, I can categorically say that 15F and 72 hours below freezing will not faze a trunking CIDP one bit. They will only take a minor bit of frond burn from those temps, assuming they are properly trunking. Size is everything when it comes to hardiness with CIDP's, as is the case with most palms. The bigger ones in London took practically zero damage from a low of 20-22F last winter, in what was an abnormally cold winter. Smaller ones may have been severely damaged or killed even, but bigger trunking specimens were practically unscathed. Even central London went down to 21-22F last winter and all the bigger CIDP's still look pristine. 

Regarding the Theophrasti vs Jubaea debate, you need to remember that Theophrasti in its native range grows in areas where the roots are almost permanently submerged in water. So in terms of wet-cold, Theophrasti is almost certainly superior. They will take quite a bit of wet-cold and come out fine, down to about 20F. Probably 10F even. My Theophrasti here took 18F in the ground fine. They are probably similar to CIDP in terms of wet-cold hardiness and their temperature limitations. However Jubaea is definitely more bud-hardy. There is evidence of Jubaea's surviving winters in parts of the UK where CIDP's and Theophrasti's have been killed off. So Jubaea's are definitely more bud-hardy than CIDP's and Theophrasti's, although there are lots of variables at stake.

The reason that Jubaea's do not survive in places like Texas and the southern USA is due to the high humidity, high rainfall and high nighttime temps during summer. Less so due the winter lows. They probably took the extreme winter lows during the February 2021 freeze in Texas, only to further succumb to the high rainfall, high humidity and high nighttime temperatures in spring/summer. All of which stressed Jubaea, combined with the extreme winter lows. Jubaea is definitely more bud-hardy in the UK though, compared to CIDP and Theophrasti. Jubaea is without a shadow of a doubt the hardier palm. Even in regards to wet-cold, at least here in the UK at 51N. 

There have been Jubaea that took wet low teens in the Dallas area I believe but suffered. From what I heard none came back after last February.

Im trying purported Theophrastii var. Golkoy seeds, which I have read are likely a natural hybrid of Theophrastii and Dactylifera. I had great germination rate so I will have plenty of test subjects. I’ve started sharing a few as well.

[Will]

8 hours ago, Meangreen94z said:

Before last February everything I had read said they were hardy to about 15*F or so(-9.4*C). They have consistently come back in Central Texas and the Dallas areas from temperatures in the -2* to 4*F (-18.9 to -15.5*C)  range in February. Not a brief cold, but 2 consecutive nights of those low temperatures and 5 days straight below freezing.

Theophrastii, Dactylifera, and  Sylvestris with a growth point above the snow/ice are all dead from those temperatures. In a wet cold Canariensis is definitively the hardiest Phoenix.

That's interesting. Could it be that they might have adapted a bit? Are seeds available of those hardy specimens?

[Meangreen94z]

3 hours ago, Will said:

That's interesting. Could it be that they might have adapted a bit? Are seeds available of those hardy specimens?

I’m sure seed will be available, I’m not sure if the CIDP in Texas and New Mexico have any genetic benefit over any other strain . Here are pictures from the palmageddon thread. 

 

 

JWITT claims this CIDP in Alamogordo, New Mexico saw -10F(-23*C) in 2011. Although I’m sure it was a more brief event

 

[MSX]

 

On 9/17/2021 at 11:46 PM, Axel Amsterdam said:

Interesting, are they grown grown is some climate controlled environment? Because the area seems to cold for palms judging from the pics on streetview. 

They're at the same 37N latitude as St. George in Utah, same 8b zone and same dry desert climate. But what is more interesting how their Washies survived at all-history extreme low -22C and a week without defrosting in February 2014 Annual Report on Global Extreme Climate Events

and a brief insight into the weather conditions, from Weatherspark Termez Airport Temperature History February 2014

Freezings fogs, freezing rain, snow - obviously it wasn't the driest freezing week

And here are some survivors in Termez, Uzbekistan, the screenshots are from various sources/youtube videos, Termez is a very old town on the banks of the Amu Darya river, Alexander the Great named it Termez or thermos in Greek language which means hot, and it really gets hot there in summers, good for palms.

A Filibusta/robusta (?)

2011 https://www.youtube.com/watch?v=sPuvimgVajY&t=425s (4:11 min)

2013  before the freeze. https://boris-mavlyutov.livejournal.com/204214.html

2014 -22С

2015 https://www.youtube.com/watch?v=UgFvaou4dNE (0:02 min)

2019 https://www.youtube.com/watch?v=qIhkJL4dETg (9:29 min)

Another Washingtonia, possiby filifera

2011 https://www.youtube.com/watch?v=sPuvimgVajY&t=425s (3:30 min)

2014  -22C

2015 https://www.youtube.com/watch?v=FtrJiArTIhY (1:48 min)

2019 https://www.youtube.com/watch?v=MpRmbLIBSIw (0:35 min)

2021 https://www.youtube.com/watch?v=o3Qw2OEuTeI (0:52 min)

 

Edited September 20, 2021 by MSX

[MSX]

On 9/18/2021 at 5:28 PM, Meangreen94z said:

JWITT claims this CIDP in Alamogordo, New Mexico saw -10F(-23*C) in 2011. Although I’m sure it was a more brief event

 

Incredible, CIDP surving at -25/23C (-13F)!

Edited September 20, 2021 by MSX

[MSX]

Even the cypress trees look dead

[UK_Palms]

4 hours ago, MSX said:

Incredible, CIDP surving at -25/23C (-13F)!

Impossible. I refuse to accept that a CIDP would survive -25C combined with 200 hours below freezing, no matter how dry that cold is. Even Trachycarpus Fortunei will be killed dead where it stands from those temps. Less so due to the duration and more the extent of that extreme low. Trachy's often drop dead from -15 to -20C in Scandinavia. There's no way a CIDP would take -25C. I would say the absolute upper extremity for a mature specimen would be -20C and even that is severely pushing it. The CIDP that recovered from -18C and 250 hours below freezing in Dallas is the most reputable extreme low survivor in my opinion. The NM ones didn't take 250 hours below freezing and probably didn't take more than -18C either where they were situated.

5 hours ago, MSX said:

They're at the same 37N latitude as St. George in Utah, same 8b zone and same dry desert climate. But what is more interesting how their Washies survived at all-history extreme low -22C and a week without defrosting in February 2014 Annual Report on Global Extreme Climate Events

A lot of those extreme low temperatures in New Mexico and Uzbekistan are probably being recorded at airport stations out in the open, when the palms are situated in the town/city centres with a noticeable UHI and close to buildings too. If the airport saw -22C, there's a good chance the washies in town only saw perhaps -18C maybe. Again once you start going over -20C you are looking at total palm killer conditions for just about any species out there. Especially combined with a week straight of sub zero conditions.

Trachycarpus 'Bulgaria' has supposedly survived -27C but if you subject them to a low of -20C and 200 hours below freezing, 99% of them will die. With -25C and 200 hours below freezing, I reckon you will be looking at 100% mortality rate on Trachycarpus 'Bulgaria', mostly due to them being a gimmick. Fortunei just will not tolerate that degree of cold. No palm will. I'm not even convinced Sabal minors would take that. I get that we are talking about a dry cold here, but if they were really that hardy in general, I think there would be CIDP's and Washies growing in the Scottish Highlands. Which there obviously isn't. The UK in general is relatively mild and not overly wet, outside of the western coasts. Yet CIDP and Washies will not grow in Scotland. 

[Meangreen94z]

2 hours ago, UK_Palms said:

Impossible. I refuse to accept that a CIDP would survive -25C combined with 200 hours below freezing, no matter how dry that cold is. Even Trachycarpus Fortunei will be killed dead where it stands from those temps. Less so due to the duration and more the extent of that extreme low. Trachy's often drop dead from -15 to -20C in Scandinavia. There's no way a CIDP would take -25C. I would say the absolute upper extremity for a mature specimen would be -20C and even that is severely pushing it. The CIDP that recovered from -18C and 250 hours below freezing in Dallas is the most reputable extreme low survivor in my opinion. The NM ones didn't take 250 hours below freezing and probably didn't take more than -18C either where they were situated.

A lot of those extreme low temperatures in New Mexico and Uzbekistan are probably being recorded at airport stations out in the open, when the palms are situated in the town/city centres with a noticeable UHI and close to buildings too. If the airport saw -22C, there's a good chance the washies in town only saw perhaps -18C maybe. Again once you start going over -20C you are looking at total palm killer conditions for just about any species out there. Especially combined with a week straight of sub zero conditions.

Trachycarpus 'Bulgaria' has supposedly survived -27C but if you subject them to a low of -20C and 200 hours below freezing, 99% of them will die. With -25C and 200 hours below freezing, I reckon you will be looking at 100% mortality rate on Trachycarpus 'Bulgaria', mostly due to them being a gimmick. Fortunei just will not tolerate that degree of cold. No palm will. I'm not even convinced Sabal minors would take that. I get that we are talking about a dry cold here, but if they were really that hardy in general, I think there would be CIDP's and Washies growing in the Scottish Highlands. Which there obviously isn't. The UK in general is relatively mild and not overly wet, outside of the western coasts. Yet CIDP and Washies will not grow in Scotland. 

I’ve been through Alamogordo several times. Its a relatively small town on the downward slope coming out of the Sacramento Mountains into the White Sands valley. There might be a few degrees discrepancy depending on location but not 10*F+ (7*C) difference. The duration wasn’t  as long as the 2021 Dallas event(as confirmed by MSX’s data), but both events highlight the abuse this palm can tolerate.

 

 

[Yort]

It is very interesting to see the mixed experiences with both Phoenix theophrasti and Jubaea chilensis. And it is actually very logical that people from different areas observe different results. This is because you are not just testing the cold tolerance of a species but the total environmental package in your garden.

Last winter I tried to answer the same question as in the title of this topic. I tried to do this by eliminating outside influences by testing both species and a few extra in the lab on cold tolerance based on electrolyte leakage tests. I have just finished an article about the results in the link below for anyone who is interested in reading it:

https://www.coldpalm.nl/en/cold-tolerance-in-palms-jubaea-vs-phoenix-a-method-to-quantify-cellular-foliage-damage-in-palms-caus

 

[Axel Amsterdam]

Very interesting article Yort. For me, butia eriospatha is very hardy. I didnt lose a single frond since planting out in 2016. i have no jubaea so i cant compare. 

Some CIDPs are surprisingly hardy, even in our wet low sun winter climate. This one survived last winter unprotected after a week of continous negative temps day and night. The one next to it died though. 

[Swolte]

Great article, Yort! Bookmarking the site!

That method opens lots of opportunities for research. I have always wondered as to the effect of an acclimatization period. During our Texas freeze, plants had lots of warning as temps were hovering around 0C/72F for days before the big dip. It was definitely a killer but I think more palms survived than we would have expected (e.g., Butia, Canariensis, Dactylifera, etc...)

[MSX]

On 9/22/2021 at 4:37 AM, Yort said:

It is very interesting to see the mixed experiences with both Phoenix theophrasti and Jubaea chilensis. And it is actually very logical that people from different areas observe different results. This is because you are not just testing the cold tolerance of a species but the total environmental package in your garden.

Last winter I tried to answer the same question as in the title of this topic. I tried to do this by eliminating outside influences by testing both species and a few extra in the lab on cold tolerance based on electrolyte  leakage tests. I have just finished an article about the results in the link below for anyone who is interested in reading it:

https://www.coldpalm.nl/en/cold-tolerance-in-palms-jubaea-vs-phoenix-a-method-to-quantify-cellular-foliage-damage-in-palms-caus

 

It's awesome that people in different parts of the globe wondering the very same questions! You've done great research, and it would be very interesting if you test using your electrolyte leakage (K+ ?) method some other popular palms such as Washingonia spp vs Brahea vs Sabals, Butia, which is claimed to be one of the hardiest pinnates in some reputable resources, if not the hardiest one. Now after reading your research I start to wonder if I need to order more K-fertilizers as active potassium fertilizing (an active electrolyte) during winter season can really improve cold hardiness of any palm.

Edited September 23, 2021 by MSX

[Yort]

No, the tests I did have nothing to do with pottassium (K) but I measured the total sum of ions (electronic conductivity) that leaked from the tissue so this is both salts and sugars. 

But yes it would be possible to test many other interesting palm species but it is quite a lot of work to set up a decent experiment with statistically suficient testplants that have grown in exactly the same conditions.

I wouldn't expect any mirracles from adding K fertizer in terms of improving cold tolerance unless it has a defficiency of this element.

Edited September 23, 2021 by Yort

[MSX]

Interesting article from palms.org repository written by S. G. Saakov, a famous soviet botanist and palms researcher, specialist in the introduction and selection of ornamental plants. -13C(8.6F) in Crimea (dry subtropical climate) kills Jubaea while CIDP only suffers leaf damage. 

 

 

Edited December 6, 2021 by MSX

[DreaminAboutPalms]

Here are two more CIDP that survived in central Texas. 168+ hours below freezing, consecutive nights of 14,7,4 and half a foot of snow 

[ahosey01]

On 9/20/2021 at 5:46 PM, UK_Palms said:

Impossible. I refuse to accept that a CIDP would survive -25C combined with 200 hours below freezing, no matter how dry that cold is. Even Trachycarpus Fortunei will be killed dead where it stands from those temps. Less so due to the duration and more the extent of that extreme low. Trachy's often drop dead from -15 to -20C in Scandinavia. There's no way a CIDP would take -25C. I would say the absolute upper extremity for a mature specimen would be -20C and even that is severely pushing it. The CIDP that recovered from -18C and 250 hours below freezing in Dallas is the most reputable extreme low survivor in my opinion. The NM ones didn't take 250 hours below freezing and probably didn't take more than -18C either where they were situated.

Having lived in the desert for years I'm not as unconvinced as you.

-18C in Dallas would come with like 30-50% humidity.  -25C in Alamogordo would be near-zero humidity.  Also, in the desert the lows are often extremely brief and generally precede daytime highs (at least) above freezing.  In the winter here in Wickenburg, for example, 50F+ temp swings are not uncommon.  I have hit 27F in the morning and bounced back to 81F in the afternoon on dozens of days in the last two years alone.  In the examples where the ambient air temp never went above 0C (32F), we can be fairly certain that the strength of the desert sun raised surface temps (i.e. the temp of the palm) to at least above 0C (32F) during the day.  Most Cupressus sempervirens, which are clearly toasted in that street view capture, are good to 5F or slightly below with some damage, but not getting completely fried like that.

Separately, it would be hard to suggest that Alamogordo has any meaningful UHI effect.  The town is extremely small and sits in a bowl at the base of desert mountains - and out here, temperature inversion (where lower elevations are colder) is common.

I think -25C is crazy but not wholesale impossible, specifically in the desert.

[MSX]

1 hour ago, ahosey01 said:

 -25C in Alamogordo would be near-zero humidity. 

What is interesting is that humidity in Alamogordo was around 76-83% during those extreme lows

Edited December 7, 2021 by MSX

[DreaminAboutPalms]

Aside from the humidity during the cold spell, one of the reasons so many palms pulled through in Texas this year was because we were in a huge drought before the freeze, and obviously in Alamogordo it’s a desert so would have been super dry before 2011 freeze event. I don’t think a CIDP of any size east of the Mississippi could handle a freeze event like that. In central Texas this year, we had a night of rain, then 3 nights of ice, 2 nights of snow and then Nights of 14,7,4 following the snow. The drought saved us here. 

Also it’s important to note that sun is Quite strong here even in February where the UV index is about a 6 on sunny days that time of year. That’s basically the max UV index in Northern Europe with the exception of a week in late June when it can get to 7 or 8. You gotta think that 20 feet up in the air the temps would have been colder than ground with the windchill well below zero for multiple days and the stronger sun probably helped with that 

Edited December 7, 2021 by DreaminAboutPalms

[UK_Palms]

So Alamogordo actually saw -25C / -13F at sunrise with humidity levels of 84%. The idea of any palms surviving this, let alone CIDP's, seems crazy to me. I would expect total defoliation and probably death for Trachycarpus Fortunei even. Pretty much no palms are going to take that extent of cold. I don't want to sound ignorant, but I suspect the two CIDP's outside that restaurant in Alamogordo were either replaced 'like for like' after the freeze, or they were protected. I wouldn't be surprised if the owner cut all the fronds off, then wrapped them up thoroughly for a few days. There is no way they took -25C / -13F at such a small size, unprotected, and then came back okay. I would expect -15C / 5F to kill small CIDP's dead of that size, even in a dry, desert climate.

Are there any other palm survivors from Alamogordo? Any other species, or specimens whatsoever? I also have to question that temperature reading of -25C / -13F. Perhaps it was far higher than that, like say -15C / 5F...? I know it isn't the most reliable source, but Wikipedia has Alamogordo's record low as -20C / -4F set during 1962. That raises questions about how cold it really got there in 2011...? Las Cruces International Airport only went down to -18C / 0F on the 3rd Feb 2011 and had a high of -9C the day before that, so although still very cold, it does seem unlikely that Alamogordo would have seen -25C / -13F, but not impossible. It certainly raises more questions. I personally don't think it got anywhere near that cold, and if it did, those CIDP's must have been protected, surely!?

[DreaminAboutPalms]

18 minutes ago, UK_Palms said:

So Alamogordo actually saw -25C / -13F at sunrise with humidity levels of 84%. The idea of any palms surviving this, let alone CIDP's, seems crazy to me. I would expect total defoliation and probably death for Trachycarpus Fortunei even. Pretty much no palms are going to take that extent of cold. I don't want to sound ignorant, but I suspect the two CIDP's outside that restaurant in Alamogordo were either replaced 'like for like' after the freeze, or they were protected. I wouldn't be surprised if the owner cut all the fronds off, then wrapped them up thoroughly for a few days. There is no way they took -25C / -13F at such a small size, unprotected, and then came back okay. I would expect -15C / 5F to kill small CIDP's dead of that size, even in a dry, desert climate.

Are there any other palm survivors from Alamogordo? Any other species, or specimens whatsoever? I also have to question that temperature reading of -25C / -13F. Perhaps it was far higher than that, like say -15C / 5F...? I know it isn't the most reliable source, but Wikipedia has Alamogordo's record low as -20C / -4F set during 1962. That raises questions about how cold it really got there in 2011...? Las Cruces International Airport only went down to -18C / 0F on the 3rd Feb 2011 and had a high of -9C the day before that, so although still very cold, it does seem unlikely that Alamogordo would have seen -25C / -13F, but not impossible. It certainly raises more questions. I personally don't think it got anywhere near that cold, and if it did, those CIDP's must have been protected, surely!?

Lots of surviving Washingtonia. I was on google maps street view and shocked to see lots of robusta dominant hybrids survive that. 

 

https://www.palmtalk.org/forum/index.php?/topic/69797-more-alamogordo-new-mexico-8a-palm-tree-pics/

 

Check out this thread. Lots of survivor pics 

Edited December 7, 2021 by DreaminAboutPalms

[UK_Palms]

@Dreaming_of_Zone_15b If all of those palms survived the 2011 freeze, there is no way they took -25C / -13F back then, especially when they were much smaller too. It couldn't have been anywhere near that cold, surely. Robusta dominant hybrids and CIDP's would not take -25C / -13F with 83% humidity. That is basically a 5b winter in a 7b/8a zone.

I would say -20C is the absolute limit for them, but that is still pushing it, even in a dry, semi-arid or desert climate. CIDP's have died from -12C to -14C along the French Med and they have been killed by -18C in the Atlas Mountains of Morocco, which is even drier than Alamogordo. There may not be much moisture in the air, but the moisture that exists within the cells of the palm will still freeze to the point of death at a certain temperature. When the cells freeze and expand the cells are destroyed. The smaller the palm, the more susceptible due to less mass and insulation. 

There's no way small CIDP's are taking -20C or lower and surviving. I suspect Alamogordo only went down to -18C or something during the 2011 event, similar to Las Cruces. Even that is hard to believe though. I wonder if people protected many of those ones during the 2011 freeze? I could imagine quite a few of them have been planted since the freeze as well. Nonetheless, the CIDP's and Robusta hybrids in that thread have probably survived temperatures that are almost unheard of anywhere. 

[Jimhardy]

Dry cold is a whole different ballgame then "wet" cold, it breaks some peoples

brains to try and understand that the desert is different. Period