Canary island date palm hardiness

[jwitt]

Mere blocks from a -5f reporting station. 

You can believe what you want. Facts speak for themselves. 

[jwitt]

@UK_PalmsJjust for your information, I report out as -10f in Alamogordo as there can be no dispute.  Now you switch to robustas. Those you are speaking of were reported in NE Alamogordo.  In my heart, and knowledge of the area and also the storm, they endured temperatures lower than what I claim.  That is near certain fact.

Like I said, CIDP hardiness has been rewrote, and maybe unknown. Same for some other species. 

You want to dispute the -10f? I use it(-10f), as it is indisputable. Sorry grasshopper 🦗 

First pic is zoomed on the Alamogordo area(a city of about 20,000- no UHI.)

OFFICIAL TEMPS 

[COpalms]

3 hours ago, UK_Palms said:

 

Right, so if it really was -10F / -23.3C in Alamogordo on 2 consecutive nights, that means Washingtonia Robusta is actually hardy down to at least -23C / -24C. That seems ludicrous and would also suggest that a fat trunked Filifera would take something crazy like -25C to -30C.

 

This is somewhat relevant to the discussion of CIDP hardiness by establishing the exact minima that was seen at Alamogordo, which I have been questioning... and do still question. Only due to how ludicrous it sounds, that Robusta's would come through that. 🤔

Although i agree with you i also disagree because personal experience can override a scientific rating. At least I think so. You also live in the UK which is quite warm and wet a lot. You guys can literally grow tree ferns and cycads! Also I feel like hardiness can depend on the palm, the climate, and where it is planted. I forgot to mention when it was planted.  I think a washingtonia robusta could take -10f/-23c simply because I don't know where it was planted, how it it is, when it was planted, and I don't know the climate. Plus many people change hardiness ratings. Lab reports state that the rhapidophyllum hystrix (or needle palm) is hardy to zone 5a (-20f or -28c). However I've seen many people change that to -5 or even 0 degrees because they don't think its reliable to trust THE PROFESSIONAL BOTANISTS. That said I don't doubt you but I also do at the same time and I think a  Washingtonia robusta could've taken that low of temp but been defoliated and probably was in rough shape.

[jwitt]

@COpalms

They were all defoliated.

And they were defoliated again the following December. (Feb 2011/Dec 2011).  

[MarcusH]

1 hour ago, COpalms said:

Although i agree with you i also disagree because personal experience can override a scientific rating. At least I think so. You also live in the UK which is quite warm and wet a lot. You guys can literally grow tree ferns and cycads! Also I feel like hardiness can depend on the palm, the climate, and where it is planted. I forgot to mention when it was planted.  I think a washingtonia robusta could take -10f/-23c simply because I don't know where it was planted, how it it is, when it was planted, and I don't know the climate. Plus many people change hardiness ratings. Lab reports state that the rhapidophyllum hystrix (or needle palm) is hardy to zone 5a (-20f or -28c). However I've seen many people change that to -5 or even 0 degrees because they don't think its reliable to trust THE PROFESSIONAL BOTANISTS. That said I don't doubt you but I also do at the same time and I think a  Washingtonia robusta could've taken that low of temp but been defoliated and probably was in rough shape.

Where I live in San Antonio , the 1980s were brutally cold with record lows of 5F , yet you still see numerous Washingtonia Filiferas and Sabals Mexicana/Palmetto that were planted way before the 1980s.  In Feb 2021 , we call it Palmageddon,  San Antonio got down to 9F . Many pure Robustas survived.  Filiferas and Sabals had no issue dealing with the cold. That's proof enough of some palms can take a lot colder temperatures.  

[jwitt]

Maybe time for the discussion.

Needle palm survived -23f in Knoxville some years back. That is now the standard and that is where that came from.  1 specimen, I believe. 

Nobody talks about the sabal minors(multiple specimens) surviving -22f in Denver a couple years ago. 

And now, multiple events, multiple locations and hundreds of CIDP's(yes,I said hundreds) surviving zero and below in both wet and dry climates. 

But yet here we are. 

There is even speculation CIDPs survived in Tallahassee below zero in the late 1800's. 

I rest my case. 

 

[MarcusH]

12 minutes ago, jwitt said:

Maybe time for the discussion.

Needle palm survived -23f in Knoxville some years back. That is now the standard and that is where that came from.  1 specimen, I believe. 

Nobody talks about the sabal minors(multiple specimens) surviving -22f in Denver a couple years ago. 

And now, multiple events, multiple locations and hundreds of CIDP's(yes,I said hundreds) surviving zero and below in both wet and dry climates. 

But yet here we are. 

There is even speculation CIDPs survived in Tallahassee below zero in the late 1800's. 

I rest my case. 

 

I believe you Jim. CIDPS are extremely bud hardy but not leaf hardy . I see them bouncing back every time after a hard freeze . One CIDP in our neighborhood was probably planted when the neighborhood was built in the mid 1970s . That CIDP is as high as a 2 story building.  Your observations are remarkable, Jim. 

[jwitt]

13 minutes ago, MarcusH said:

I believe you Jim. CIDPS are extremely bud hardy but not leaf hardy . I see them bouncing back every time after a hard freeze . One CIDP in our neighborhood was probably planted when the neighborhood was built in the mid 1970s . That CIDP is as high as a 2 story building.  Your observations are remarkable, Jim. 

Minors and needles are not leaf hardy to -20f either. 

Our knowledge of some palms has been rewritten, whether we like to admit it or not.

One other observation I would like to make is there are not many places in the world warm enough to support these palms and(the "and" is important) susceptible to below zero weather outside certain parts of the US.  Add in the truly limited time palms have been grown in these parts(a century and less) for the most part, 2 things are happening.....

We are witnessing the rewriting of palm knowledge, whether "we" want to admit or acknowledge it does not matter. 

It happened. 

We may not even have found the limits yet!

 

 

[UK_Palms]

@jwitt I must concede to you after further analysis and having assessed your posts. It's not that I didn't believe what you were saying, it's just very hard to imagine CIDP or Washingtonia coming back from -24C. But you have provided fairly conclusive evidence to back this up so I must accept this. It certainly re-writes a lot of what was previously thought about hardiness (at least in dry, arid places).

What in your opinion is the most extreme example of survival in terms of CIDP or Washingtonia coming back? Would it definitely be the Alamogordo ones? Or are there any other examples of them surviving even colder temperatures than that in other places? Any examples of CIDP or Washingtonia taking -15F or lower and coming back?

Also I saw these CIDP's in Alamogordo on street view...

[VA Jeff]

There are some at least 60 foot tall CIDPs around the old courthouse in Brunswick, GA,  They were trunking back in 1985, when the low temperature reportedly got down to 6F.  If you had the same palms in zone 8 Virginia at 16F, there is a good chance they'd be dead.   If I see multiple palms of the same species survive an extreme cold event, it makes me think that there is more importance to the overall conditions being conducive rather than it being better genetics or that the palms can regularly survive those temps in a borderline area.

 

[jwitt]

3 hours ago, UK_Palms said:

@jwitt I must concede to you after further analysis and having assessed your posts. It's not that I didn't believe what you were saying, it's just very hard to imagine CIDP or Washingtonia coming back from -24C. But you have provided fairly conclusive evidence to back this up so I must accept this. It certainly re-writes a lot of what was previously thought about hardiness (at least in dry, arid places).

What in your opinion is the most extreme example of survival in terms of CIDP or Washingtonia coming back? Would it definitely be the Alamogordo ones? Or are there any other examples of them surviving even colder temperatures than that in other places? Any examples of CIDP or Washingtonia taking -15F or lower and coming back?

Also I saw these CIDP's in Alamogordo on street view...

Thank you.!

I will speak to the 2 CIDP at the A&W. I mentioned I did not see them with my own eyes during the event. I knew of them beforehand. What I saw was them on a newscast doing a report as the news was driving down the street.  Never did I suspect they would survive.  I did not expect much to survive statewide or even El Paso. Outside maybe needles or minor had survived anything even approaching those temperatures. 

That said, the newscast was in Alamogordo as it was reported as being -21 f in NE Alamogordo. That would be near a canyon that would have dumped that cold

air into that part. Our cold comes from the east thru the mountains in the big Arctic events. 

So that -10f I reference is an estimate for NE Alamogordo.  Placed there as a  safe, "best guess". 

The graph I provided is an actual NWS site closer to to the CIDP's and the same elevation.  It shows back to back nights of -12f and -13f! That first night was also with east high winds(25-30mph), stronger closer to the mountains or near the mouth of canyons. 

So I stick with the -10f and you know the rest of the story.  That is why I sometimes state it was colder. 

That is why also those NE Alamogordo robustas are so impressive. 

The sensor in question reported -21f then died. 

From NWS,  figure 15, and and the -10f in NE Alamogordo. Now you know.

I suspect the NWS could not believe it..  Note they(NWS) state a few locations(more than 1, in Alamogordo)Even more incredible! But yeah, we can stick with -10f!

"03/31/2011 – Figure 15 included an erroneous Minimum Temperature of -21°F in northeast Alamogordo. This was 
removed, and replaced with a -10°F reading from northern Alamogordo. A sentence on page 5 which originally read, 
“While most of the Tularosa Basin was in the -10s, a few locations on the east side of Alamogordo reached -20°F” was 
likewise changed to read: “Temperatures across the Tularosa basin ranged from -10 to -15°F.”"

Believe it or not!

[jwitt]

And just in case it was missed in the above post!

"While most of the Tularosa Basin was in the -10s, a few locations on the east side of Alamogordo reached -20°F” was"

Not one!

Now you know the rest of the story! 

[jwitt]

So back to my original point.......

I am not sure we know the absolute minimum lethality temperature of a CIDP.  I feel it is unknown. 

My take.

Also this was a rain/snow event.  Just for the record.

[jwitt]

So imagine the ridicule I would take if I stated I know robustas that survived -20f. 

Heck, I did with the claim of filifera's surviving -11f. 

Then the argument was short cold. 

Well, not really, it was back to back nights of -11f. 

I think I kind of just proved something near -20f for some palms.  Even the NWS states it....

[jwitt]

@UK_Palms

If you have made it this far......

Let me know. I got something I would like to add....