Complete list of “Bullet Proof” Palms?

[Dwarf Fan]

This list was made by Papay, it definitely seems like one of the more comprehensive lists I have found so far to date, does anyone have a better list?

Also, if anything is missing please feel free to add more Palms no matter how obscure.

[Las Palmas Norte]

I can't grow the majority of those but according to the "zone" designation, claim I could.

[matthedlund]

Definitely not complete and likely not particularly accurate. I can tell you 100% that Trithrinax brasiliensis is not hardy to anything below 20-25 degrees F.

[jwitt]

Phoenix canariensis

Completely missing from list. 

Ultimate cold hardiness is unknown, but well below what is/and has been thought or published. 

What is known.

Most healthy, trunking plants will survive from 0f(consecutive nights at this temperature ). Survival is documented to be near 100% at this temperature, wet or dry, in multiple locations. 

Numerous specimens survived well below -10f, and (in truth)actually colder. 

So the cold hardiness remains unknown. This is different from leaf hardiness. 

Growing conditions do require a specific growing season (long).

The list for zone 8 is otherwise bogus save a few palms.  Most of those palms listed, not one speciman can be shown to have survived long-term(25-20 years) in zone 8a.  

Edited August 25 by jwitt
Additional info

[SeanK]

Sabal palmetto should be moved to z7b. Not every year, but every 5-years OK. About 50% bronzing of leaflets.

[MarcusH]

4 hours ago, jwitt said:

Phoenix canariensis

Completely missing from list. 

Ultimate cold hardiness is unknown, but well below what is/and has been thought or published. 

What is known.

Most healthy, trunking plants will survive from 0f(consecutive nights at this temperature ). Survival is documented to be near 100% at this temperature, wet or dry, in multiple locations. 

Numerous specimens survived well below -10f, and (in truth)actually colder. 

So the cold hardiness remains unknown. This is different from leaf hardiness. 

Growing conditions do require a specific growing season (long).

The list for zone 8 is otherwise bogus save a few palms.  Most of those palms listed, not one speciman can be shown to have survived long-term(25-20 years) in zone 8a.  

Washingtonia Filibusta and Phoenix Dactylifera are certainly not bulletproof in Zone 8a in fact I haven't seen one Phoenix Dactylifera surviving Palmaggedon 2021 here in downtown San Antonio which is Zone 9a .  I don't know how many survived in our area I just only see newly planted ones.  

[Enar]

It would be nice to have a list we can all work together on, not only listing cold hardiness but also if the palm likes high/low humidity. Since Jubaea Chilensis for example can withstand colder temperatures but despises humidity. Is there a way to collaborate on say an excel sheet?

[jwitt]

54 minutes ago, Enar said:

It would be nice to have a list we can all work together on, not only listing cold hardiness but also if the palm likes high/low humidity. Since Jubaea Chilensis for example can withstand colder temperatures but despises humidity. Is there a way to collaborate on say an excel sheet?

That palm seems to actually do quite well in some actual wet coastal climates.  Almost a "fog" palm.

Where does it despise humidity?

 

Edited August 26 by jwitt

[Enar]

6 minutes ago, jwitt said:

That palm seems to actually do quite well in some actual wet coastal climates.  Almost a "fog" palm.

Where does it despise humidity?

 

Alabama zone 8a 60-80% humidity some days. Had multiple die for no reason. Reminded me of fungi death. 

[Ben OK]

40 minutes ago, Enar said:

Alabama zone 8a 60-80% humidity some days. Had multiple die for no reason. Reminded me of fungi death. 

I am certainly not an expert on Jubaea in particular, but is it possible that Jubaea actually dislike the high nighttime temps of the coastal southern US? There are a lot of plants that don't love high overnight temps, if they aren't native to regions where those conditions are common.

The reverse can be true also, as in the case of very tropical palms like coconuts. It seems just as rare to see a coconut growing in Mediterranean climates as it is to see a jubaea looking good in a more tropical marine climate.

On the other hand, there probably aren't a lot of gardeners in those humid tropical climates clamoring to grow jubaea. They have plenty of cheaper, faster-growing options.

[jwitt]

1 hour ago, Enar said:

Alabama zone 8a 60-80% humidity some days. Had multiple die for no reason. Reminded me of fungi death. 

Seemed to do ok in Dallas/San Antonio.

Cold took em out there. 

Can't think of a much more humid a climate than a fog belt, they seem to do ok there. 

Personally always leaned towards a soil thing.  I could be all wrong tho.

As far as the nighttime low thing,  doesn't seem to be a factor in PHX, or DFW and SA

 

 

Edited August 26 by jwitt
Nighttime

[Chester B]

This list is very optimistic to be honest. I’ve never seen 15f and I’ve killed many of these palms. 
 

A lot of those “8a palms” will be killed by those temps. 
 

Also it’s very situational it’s not a one size fits all. 

[Dwarf Fan]

2 hours ago, Enar said:

It would be nice to have a list we can all work together on, not only listing cold hardiness but also if the palm likes high/low humidity. Since Jubaea Chilensis for example can withstand colder temperatures but despises humidity. Is there a way to collaborate on say an excel sheet?

Being still a bit of a new guy I just assumed that of course that there was, I mean there had to be a “List”… somewhere… RIGHT?!?

Well, I have been looking for over a month and this was the closest thing to a legitimate “List” I have run across so far. I have been compiling a personal “List” but I don’t really include Palms over 35 feet max height or blue/silver or Salt sensative palms. So my list is not ever going to be comprehensive and useful to everyone.

I am all for collaborating on a “Master List” of Cold Hardy palms but personally I HATE the look of spreadsheets. I would personally prefer a simple list but if a spreadsheet is easier for everyone so be it.

I personally would like to see the “Zones” usage BS completely done away with and instead have a “survival temp” (spear pull is okay as long as it regrows) BUT what would be optimal is if whenever possible temps were given with a range that starts with “showed SOME visual damage” and have BOTH temps listed so that we could get “damage to near death temp ranges” clarified so that we can all collectively make more informed species decisions.

I think humidity levels should also be included whenever possible as well, if it were up to me.

[Tom in Tucson]

1 hour ago, jwitt said:

Seemed to do ok in Dallas/San Antonio.

Cold took em out there. 

Can't think of a much more humid a climate than a fog belt, they seem to do ok there. 

Personally always leaned towards a soil thing.  I could be all wrong tho.

As far as the nighttime low thing,  doesn't seem to be a factor in PHX, or DFW and SA

They may grow fairly well in parts of Texas, but they hate the intense AZ sun. If the low temps. of Phoenix are very high for a long period, they can (and do) die. Here in Tucson I only know of 2 (1 mine in 50% shade, the other at UofA in 80% shade).

One other fact: The cool foggy climate of California is by far the best climate for this species to thrive, despite the higher humidity.

Hi 109˚, Lo 78˚

 

 

Edited August 26 by Tom in Tucson

[jwitt]

10 hours ago, Tom in Tucson said:

10 hours ago, Tom in Tucson said:

 

There are anecdotal evidence and even posts on palmtalk about this palm and sun in Phoenix. 

Even your 2 examples In Tuscon kind of dispel the overnight low discussion. Shaded areas are most likely even warmer at night. 

Actual scientific data on the palms in natural habitat note 2 things that get my attention.

1. They are most abundant on highly solar irradiated NE(southern hemisphere) slopes. 

2. They are also abundant with the protection of an overstory plant when young. I interpreted it like a saguaro/palo Verde thing. 

[Matt N- Dallas]

23 hours ago, MarcusH said:

Washingtonia Filibusta and Phoenix Dactylifera are certainly not bulletproof in Zone 8a in fact I haven't seen one Phoenix Dactylifera surviving Palmaggedon 2021 here in downtown San Antonio which is Zone 9a .  I don't know how many survived in our area I just only see newly planted ones.  

There are Phoenix dactylifera in SA that survived the freezes of the 1980’s as well as the 2021 freeze.  There’s an old apt complex off of San Pedro that has a number of them.  

[Matt N- Dallas]

14 hours ago, jwitt said:

Seemed to do ok in Dallas/San Antonio.

Cold took em out there. 

Can't think of a much more humid a climate than a fog belt, they seem to do ok there. 

Personally always leaned towards a soil thing.  I could be all wrong tho.

As far as the nighttime low thing,  doesn't seem to be a factor in PHX, or DFW and SA

 

 

I don’t think the high night time lows of summer are taking them out.  There are two +20 years jubaeas in Dallas that have not been bothered by summer lows in the 80’s.  

[kinzyjr]

It might be easier to start with the Cold Hardiness Master Data spreadsheet and put the species into a list based on what temperature they have a > 50% chance of surviving.  50% was arbitrary, so if you would rather go with 2/3 (67%) or another higher number, it might be a better list.  The sheet is the combined observations from the Freeze Forums, Larry Noblick's spreadsheet, and the long-time observations of CFPACS members.

[Allen]

There is too many variables to "Bullet Proof" to list.   Maybe the simplest is seeing what palms have been in your area for 10, 25, 50 or 100 years.  But then what time frame constitutes Bullet Proof?

[MarcusH]

29 minutes ago, Matt N- Dallas said:

There are Phoenix dactylifera in SA that survived the freezes of the 1980’s as well as the 2021 freeze.  There’s an old apt complex off of San Pedro that has a number of them.  

I personally haven't seen any in San Antonio after the big freeze in 2021 but SA is a large city. The ones at Tobin Center all died . A lot of others died as well which makes them not bulletproof for 8a . 

[MarcusH]

1 minute ago, Allen said:

There is too many variables to "Bullet Proof" to list.   Maybe the simplest is seeing what palms have been in your area for 10, 25, 50 or 100 years.  But then what time frame constitutes Bullet Proof?

To me bulletproof is die at natural cause like age not cold . 

[Allen]

5 minutes ago, MarcusH said:

To me bulletproof is die at natural cause like age not cold . 

Good idea.  The problem is palms are so cold sensitive and you can't predict the future.  What happened in Texas may happen next year or it might be never.  So Bullet Proof this year might end next year

Edited August 26 by Allen

[Matt N- Dallas]

A number of them survived there.  My dactylifera in San Marcos survived unprotected yet Theophrastii did not.  

[Silas_Sancona]

3 hours ago, jwitt said:

. They are also abundant with the protection of an overstory plant when young. I interpreted it like a saguaro/palo Verde thing. 

I wouldn't take that as 100% gospel..  

There are Saguaro dropping like flies all over the valley ..due -in large part- to the extreme overnight lows this summer, both in town and out in the desert.  Some excellent research from researchers at the Desert Laboratory on Tumamoc Hill / Saguaro Nat. Monument documenting Saguaro moving uphill / to north facing slopes ..to escape increasingly hot temperatures..

ALL plants have thresholds they will ..and won't  tolerate..

[MarcusH]

2 minutes ago, Matt N- Dallas said:

A number of them survived there.  My dactylifera in San Marcos survived unprotected yet Theophrastii did not.  

Me personally I haven't seen any old Phoenix Dactylifera in the SA area and I get around a lot I'm not claiming there aren't any , the few ones I see are planted after 2021 on the South Side and it seems to be people hesitate planting it in most cases so far . It's a beautiful palm but this decade is so unpredictable with 2 severe freezes in 3 years I'm not taking more chances dealing with palms that can't or maybe handle our severe freezes.  I already made that mistake ones by planting 2 Queens and a Wash. Robusta. All my palms planted prior to last year's freeze actually surivived with minimal protection since they're still young . I'm growing pure Filiferas at this moment as a back up palms. Whichever gets killed by the freeze will be replaced by a Filifera and Sabal Mexicana.  I was thinking of a Mule but I'm not sure . Definitely not as cold hardy as a Filifera and Sabal Mexicana.  

[fr8train]

Where I am now is zone 8b, but according to historic cold snaps it should be 6b based on that book. It's gotten down to 0F here according to wikipedia. 

I think zones are based on average lows and not cold snaps. Cold snaps in all of those can be much lower. 

Edited August 26 by fr8train

[fr8train]

1 hour ago, Matt N- Dallas said:

A number of them survived there.  My dactylifera in San Marcos survived unprotected yet Theophrastii did not.  

Do you have pictures of your dactylifera now? 

[fr8train]

1 hour ago, MarcusH said:

Me personally I haven't seen any old Phoenix Dactylifera in the SA area and I get around a lot I'm not claiming there aren't any , the few ones I see are planted after 2021 on the South Side and it seems to be people hesitate planting it in most cases so far . It's a beautiful palm but this decade is so unpredictable with 2 severe freezes in 3 years I'm not taking more chances dealing with palms that can't or maybe handle our severe freezes.  I already made that mistake ones by planting 2 Queens and a Wash. Robusta. All my palms planted prior to last year's freeze actually surivived with minimal protection since they're still young . I'm growing pure Filiferas at this moment as a back up palms. Whichever gets killed by the freeze will be replaced by a Filifera and Sabal Mexicana.  I was thinking of a Mule but I'm not sure . Definitely not as cold hardy as a Filifera and Sabal Mexicana.  

Mules are surprisingly hardy if they survived palmageddon. The two at the Oblate School of Theology are still alive following 2021 and 2022 cold snaps. I recently saw one in Seguin too, though I don't know when it was planted. There are plenty at palm buddha that are still alive. 

[MarcusH]

7 minutes ago, fr8train said:

Mules are surprisingly hardy if they survived palmageddon. The two at the Oblate School of Theology are still alive following 2021 and 2022 cold snaps. I recently saw one in Seguin too, though I don't know when it was planted. There are plenty at palm buddha that are still alive. 

Yes they are and a big eye catcher as well.  He's got a huge selection of Mules every time I go there makes me feel like walking into a jungle. 

[Matt N- Dallas]

15 minutes ago, fr8train said:

Mules are surprisingly hardy if they survived palmageddon. The two at the Oblate School of Theology are still alive following 2021 and 2022 cold snaps. I recently saw one in Seguin too, though I don't know when it was planted. There are plenty at palm buddha that are still alive. 

 

19 minutes ago, fr8train said:

Do you have pictures of your dactylifera now? 

 

[fr8train]

Nice! It looks great. What was the ultimate low it saw? Maybe I'll try one here. I'm by Boerne and I swear this area gets colder than the I-35 corridor, but maybe it can make it. 

Edited August 26 by fr8train

[Matt N- Dallas]

It and another dactylifera survived the Feb, 2021 cold blast w/ an ultimate low of 6*F - unprotected.  It was defoliated by last Dec’s low of 14* and has dealt w/ a brutal drought this year- usually the leaves are larger.  

[Matt N- Dallas]

Butia yatay x Syagrus rom today in San Marcos, TX

[jwitt]

6 hours ago, Silas_Sancona said:

I wouldn't take that as 100% gospel..  

There are Saguaro dropping like flies all over the valley ..due -in large part- to the extreme overnight lows this summer, both in town and out in the desert.  Some excellent research from researchers at the Desert Laboratory on Tumamoc Hill / Saguaro Nat. Monument documenting Saguaro moving uphill / to north facing slopes ..to escape increasingly hot temperatures..

ALL plants have thresholds they will ..and won't  tolerate..

I always thought the simbiote was more a water thing than temperature.  The overstory takes the edge(sun) off, there by needing less water, yada, yada, until the water tank has enough storage.  Just my thoughts. 

Summer really did not start until July.  When it did, it was hot,  continuous, and without break.  

The .06" since April 1 at Sky harbor can't help either.  Monsoon has also been non existent in my backyard. 

Sad to see that AZ icon suffer in its home range as it adjusts north slope and uphill. 

 

 

 

Edited August 26 by jwitt

[SeanK]

22 hours ago, jwitt said:

That palm seems to actually do quite well in some actual wet coastal climates.  Almost a "fog" palm.

Where does it despise humidity?

 

San Francisco is foggy yet receives only 20 inches of rain in a normal year.  W.filifera is a good example. It does OK in ABQ but can't take similar minimums in ATL..  Our daily temperature swings are 20° on "dry" days but only 10° on damp days. 

[Silas_Sancona]

3 minutes ago, jwitt said:

I always thought the simbiote was more a water thing than temperature.  

Summer really did not start until July.  When it did, it was hot continuous without break.  

The .06" since April 1 at Sky harbor can't help either.  Monsoon has also been non existent in my backyard. 

Wonder if the saguaro are also extending their upper elevation range. 

Sad to see that AZ icon suffer in its home range. 

Lack of rain has definitely added to the stress for sure but, as was mentioned in an  ..actually decent..  news story last night,  when it is as hot -overnight- as it has been,  in the city esp,  Saguaro ..and other cacti  struggle to breathe  ( since they only do that at night )  and essentially suffocate. Add sunburn causing additional damage and the result can be a massive dead thing in your yard..  I lost a few things myself.

The story also showed ( as someone in the story was cutting up a big specimen ) how the soft tissue surrounding it's core was completely rotted below what looked like a barely damaged surface layer..

There had been other news stories as people started noticing them dropping arms/ leaning / falling over in July  but the story last night  was the first one where the  " how cacti breathe at night " aspect was emphasized for the general public.

Saguaro haven't been the only things severely impacted by last month's heat either ..LOTS of Agave melting around town too.. 


As far as any longer term shifts?  I do believe a shift up  in elevation is being seen too ..along with a more general shift out of the core area here in AZ.

 Overall, for the Monsoon, it has definitely been awful state-wide, and there in N.M as well..  There have been a few, extremely local spots, which have actually received decent rain though.

  Going to be really interesting to see if we / Sky Harbor gets anything more in the 30-ish days that are left in the season, or if this year ends up being the driest recorded, in PHX at least.. Tucson is below avrg. atm,  but not by much, surprisingly.

As hot as it was, even up on the rim, i won't be shocked to hear of issues w/ the Juniper / Pinyon in areas up there later, esp. if this winter leans drier.  Only so much of X stressor factor(s) living organisms will handle before reaching their breaking point. 

 

[Tom in Tucson]

13 hours ago, jwitt said:

 

Don't ignore the fact that a cold Antartic current is found along all of the Chilean coast (cool nights and frequent fog). It's very similar to the Californias (alta & baja) coast. That's why they excel there. As I said before they hate intense sunlight, like in Phoenix.

Hi 108˚, Lo 83˚

Edited August 27 by Tom in Tucson

[jwitt]

2 hours ago, SeanK said:

San Francisco is foggy yet receives only 20 inches of rain in a normal year.  W.filifera is a good example. It does OK in ABQ but can't take similar minimums in ATL..  Our daily temperature swings are 20° on "dry" days but only 10° on damp days. 

I was actually thinking a bit up the coast, Eureka ca,- Brandon Or.   On par precip wise with Atlanta or pretty close, but very cool(year round), very damp winters. 

ATL vs ABQ.  Beyond moisture, length of freeze, and solar are on the opposite spectrum.

[jwitt]

9 minutes ago, Tom in Tucson said:

Don't ignore the fact that a cold Antartic current is found along all of the Chilean coast (cool nights and frequent fog). It's very similar to the Californias (alta & baja) coast. That's why they excel there. As I said before they hate intense sunlight, like in Phoenix.

Hi 108˚, Lo 83˚

Maybe I read the wrong stuff. I thought they grew on the continent side of the coastal range favoring highly solarized(NE) slopes. 

Guess they would hate it more here than PHX then(intense sunlight). Thanks! 

Wonder how the full sun one in El Paso is able to survive.  Got to be some intense sunlight at 4000'. 

[Silas_Sancona]

6 minutes ago, jwitt said:

Maybe I read the wrong stuff. I thought they grew on the continent side of the coastal range favoring highly solarized(NE) slopes. 

Guess they would hate it more here than PHX then(intense sunlight). Thanks! 

Wonder how the full sun one in El Paso is able to survive.  Got to be some intense sunlight at 4000'. 

iNat data: https://www.inaturalist.org/taxa/123353-Jubaea-chilensis