Archontophoenix alexandrae

[Jim in Los Altos]

26F minimum, very little frost. My unprotected almost 3' tall one is showing about 40% leaf burn.

[spockvr6]

Here is a typical leaf on one of my small A. alexandrae after 34F and very light frost.  This photo was taken about 10-12 hours after the frost.  A week later this leaf was a torched and krinkled up mess.

These are not frost tolerant palms!

[spockvr6]

Guys-

As long as the damage is just to foliage....have no fear with these palms.  They will come back hard.

Here is a photo of some of mine that were hammered last Feb 14th (see my post above).   At the time, these palms were maybe 3 ft tall.  They were my smallest alexandrae and were thus good "testers".

Today, they are over 6 ft tall and any damaged foliage is gone.   Growth rate was not affected at all.

[DoomsDave]

Well, the news from Guada la Habra no look so beuna.

Here's some A. alexies, KFC'd  a couple of weeks after they were exposed to three nights of 24.8 F (-4.4 C) and a fourth consecutive night at 27.8 F.

Sigh.

But, they're starting to recover.

Time'll tell.

[DoomsDave]

No end of misfortune for this one.

First, slashed, now freeze-damaged.  No frost, though.

Four nights of about 28-29 F.

[Jim in Los Altos]

Mine suffered about the same amount of damage as my A. cunninhamianas at 26F with 50% leaf burn. The good news is that it is recovering at a higher rate of speed than A. cunninghamiana, a pleasant suprise.

[Bilbo]

Interesting Jim; I thought A.cunn was hardier of the Kings according to all my books but there doesnt seem much in it.

I would vey much like a King so maybe I will go with my first choice but I dont know yet.

I am going to have a "Royal Family" in my back yard!

Queen planted last September is laughing away with no problems and I will soon be piling on the Nitrate.

Then it will be a King and a Royal the latter of which is difficult to source in UK but then like all of us here I wouldnt be in palms without patience!

Regardez

Juan

[sonoranfans]

(Bilbo @ Apr. 24 2007,06:48)

QUOTE

Interesting Jim; I thought A.cunn was hardier of the Kings according to all my books but there doesnt seem much in it.

I would vey much like a King so maybe I will go with my first choice but I dont know yet.

I am going to have a "Royal Family" in my back yard!

Queen planted last September is laughing away with no problems and I will soon be piling on the Nitrate.

Then it will be a King and a Royal the latter of which is difficult to source in UK but then like all of us here I wouldnt be in palms without patience!

Regardez

Juan

I am not an authority on kings, but on the internet multiple sources claim the cunninghama are "not more frost tolerant than the alexandre, they are just less sun tolerant and tend to be planted under canopies which tend to hold the heat better".  I have no personal experience, was just reading about kings in general.  I have seedlings in the greenhouse of purpea, alexandre, and maxima and so far the alexandre are definitely the fastest growing, though I know the maxima are regarded as the fastest by palm authorities.  Since they are all small yet, my observations may not mean much.

[osideterry]

All 5 of my A. cunninghamianas endured 25-26F low, with several hours over a few nights subfreezing, with 50%-75% leaf burn. My one A. alexandera was 100% defo'd, and finally succumbed to "The Pink" 2 weeks ago. Geof rates it at 30F in the SoCal book, which seems right to me.

It's possible they are hardier once mature, but I'll go with any other Archo before trying another alex.

[Walt]

I've got many species of Archontophoenix in the ground. For my money, I will take A. alexandrae any day vis-a-vis cunninghamina for cold/frost tolerance and recovery. From my experience alexandrae handles cold and frost better, but moreover, recovers more quickly than cunninghamiana. The difference is not night and day mind you, but somewhat more than subtle. At least that has been my experience.

To qualify the above, this assumes palms with at least several feet or more of trunk. I haven't tested potted specimens. I don't dare. I always keep them in a heated greenhouse if temps drop much below 40 degrees.

[sonoranfans]

(Walt @ Aug. 04 2007,19:20)

QUOTE

I've got many species of Archontophoenix in the ground. For my money, I will take A. alexandrae any day vis-a-vis cunninghamina for cold/frost tolerance and recovery. From my experience alexandrae handles cold and frost better, but moreover, recovers more quickly than cunninghamiana. The difference is not night and day mind you, but somewhat more than subtle. At least that has been my experience.

To qualify the above, this assumes palms with at least several feet or more of trunk. I haven't tested potted specimens. I don't dare. I always keep them in a heated greenhouse if temps drop much below 40 degrees.

I had ordered cunninghamina then cancelled the order and ordered the alexandrae instead when I read that the cunninghamina has the same cold tolerance(28F).  The ref I read stated that cunninghamina were mistakenly thought to be more cold tolerant because they are more sun sensitive and are generally planted under more heat retaining canopies.  I have learned from this past winter that microclimate areas in my yard are up to 4F different in nightime lows.  Also I read that the height of the trunk heart(?) above the ground really determines survivability as the ground is really the source of heat robbing cold.  Heat transfer is a really tricky subject.  A 190 degree steam bath is much hotter than a 190 degree sauna.  Its really the temp attained by the palm, not the ambient temp, and this is determined by duration of cold, proximity of the ground, wind velocity(plants have windchill also), presence of frost, diameter of the trunk, etc.  I had 3 bizzies take a burn this past winter, and there was a wide range of damage.  The smallest one, that was also closest to thehouse was the MOST damaged by far.  But it was a 6'+ palm, not a little one at all.

[Walt]

(sonoranfans @ Aug. 05 2007,11:22)

QUOTE

(Walt @ Aug. 04 2007,19:20)

QUOTE

I've got many species of Archontophoenix in the ground. For my money, I will take A. alexandrae any day vis-a-vis cunninghamina for cold/frost tolerance and recovery. From my experience alexandrae handles cold and frost better, but moreover, recovers more quickly than cunninghamiana. The difference is not night and day mind you, but somewhat more than subtle. At least that has been my experience.

To qualify the above, this assumes palms with at least several feet or more of trunk. I haven't tested potted specimens. I don't dare. I always keep them in a heated greenhouse if temps drop much below 40 degrees.

I had ordered cunninghamina then cancelled the order and ordered the alexandrae instead when I read that the cunninghamina has the same cold tolerance(28F).  The ref I read stated that cunninghamina were mistakenly thought to be more cold tolerant because they are more sun sensitive and are generally planted under more heat retaining canopies.  I have learned from this past winter that microclimate areas in my yard are up to 4F different in nightime lows.  Also I read that the height of the trunk heart(?) above the ground really determines survivability as the ground is really the source of heat robbing cold.  Heat transfer is a really tricky subject.  A 190 degree steam bath is much hotter than a 190 degree sauna.  Its really the temp attained by the palm, not the ambient temp, and this is determined by duration of cold, proximity of the ground, wind velocity(plants have windchill also), presence of frost, diameter of the trunk, etc.  I had 3 bizzies take a burn this past winter, and there was a wide range of damage.  The smallest one, that was also closest to thehouse was the MOST damaged by far.  But it was a 6'+ palm, not a little one at all.

Everything you said I agree with. I've covered this subject years ago at this and other forums.

Some folks don't fully understand the physics of wintertime cold.

What you said about the bud being elevated is true, at least during a radiational freeze when the air becomes stratified, with the coldest air being at ground level and then getting warmer with each foot of elevation.

(Two winters ago a local weather station here recorded a 14 degree F difference from ground level to 30 feet during a radiational freeze!)

I. too, have read the same thing regarding A. cunninghamiana, that the reputed cold hardiness (more so than A. alex.) is due to canopy cover.

Years ago I took extensive under-canopy verses open yard temperature readings (using digital thermometers) during radiation cooling nights/mornings during the winter. I've recorded up to 7 degrees warmer under dense canopy verses the open yard. That was the maximum, but 3-4 degrees warmer was more the norm. Soil moisture, soil temperature, density of canopy, etc., infuenced what the actual temperature were that I recorded. For instance, under canopy readings where higher on the south side of a tree, than they were on the north side. This was due to higher soil temperatures going into the night because the soil got direct solar gain/radiation during the day, where the north side didn't.

Further, I always try to plant tender palms on the south side of high tree canopy because then it can get better sun.

Absolutely a 190 steam bath is warmer than a sauna, in terms of heat transfer to the human body, due to density of the water particles.

Just like there's more heat in a 110 degree cup of coffee than there is in a lighted match. The match has more intensity of heat but far less of it (volume).

And yes, just because the ambient air temperature might drop to 30 degrees at sun up, the palm bud might not see that low a temparture due to the fact that it hasn't lost all it's heat (it had going into the night) via conduction and radiation into the ambient air. That's why a simple insulative wrap may be enough during non hard freezes to protect the bud as long as the duration of the freeze isn't too long.

[sunshine]

Hi

The A. cunninghamia is definitely more cold tolerant than A. alexandrae. In Australia where they are native you will find the A. cunninghamia growing in southern QLD and Northern NSW in areas where they get really cold Winters. The A. alexandrae are native to the warmer more tropical parts of QLD  however this year my A. alexandrae have been frosted and the ambient air temp was -3C. but fortunately it doesn't stay cold here for long once the sun appears! Some leaf burn but they'll recover in Spring.

[sonoranfans]

(Walt @ Aug. 05 2007,12:59)

QUOTE

(sonoranfans @ Aug. 05 2007,11:22)

QUOTE

(Walt @ Aug. 04 2007,19:20)

QUOTE

I've got many species of Archontophoenix in the ground. For my money, I will take A. alexandrae any day vis-a-vis cunninghamina for cold/frost tolerance and recovery. From my experience alexandrae handles cold and frost better, but moreover, recovers more quickly than cunninghamiana. The difference is not night and day mind you, but somewhat more than subtle. At least that has been my experience.

To qualify the above, this assumes palms with at least several feet or more of trunk. I haven't tested potted specimens. I don't dare. I always keep them in a heated greenhouse if temps drop much below 40 degrees.

I had ordered cunninghamina then cancelled the order and ordered the alexandrae instead when I read that the cunninghamina has the same cold tolerance(28F).  The ref I read stated that cunninghamina were mistakenly thought to be more cold tolerant because they are more sun sensitive and are generally planted under more heat retaining canopies.  I have learned from this past winter that microclimate areas in my yard are up to 4F different in nightime lows.  Also I read that the height of the trunk heart(?) above the ground really determines survivability as the ground is really the source of heat robbing cold.  Heat transfer is a really tricky subject.  A 190 degree steam bath is much hotter than a 190 degree sauna.  Its really the temp attained by the palm, not the ambient temp, and this is determined by duration of cold, proximity of the ground, wind velocity(plants have windchill also), presence of frost, diameter of the trunk, etc.  I had 3 bizzies take a burn this past winter, and there was a wide range of damage.  The smallest one, that was also closest to thehouse was the MOST damaged by far.  But it was a 6'+ palm, not a little one at all.

Everything you said I agree with. I've covered this subject years ago at this and other forums.

Some folks don't fully understand the physics of wintertime cold.

What you said about the bud being elevated is true, at least during a radiational freeze when the air becomes stratified, with the coldest air being at ground level and then getting warmer with each foot of elevation.

(Two winters ago a local weather station here recorded a 14 degree F difference from ground level to 30 feet during a radiational freeze!)

I. too, have read the same thing regarding A. cunninghamiana, that the reputed cold hardiness (more so than A. alex.) is due to canopy cover.

Years ago I took extensive under-canopy verses open yard temperature readings (using digital thermometers) during radiation cooling nights/mornings during the winter. I've recorded up to 7 degrees warmer under dense canopy verses the open yard. That was the maximum, but 3-4 degrees warmer was more the norm. Soil moisture, soil temperature, density of canopy, etc., infuenced what the actual temperature were that I recorded. For instance, under canopy readings where higher on the south side of a tree, than they were on the north side. This was due to higher soil temperatures going into the night because the soil got direct solar gain/radiation during the day, where the north side didn't.

Further, I always try to plant tender palms on the south side of high tree canopy because then it can get better sun.

Absolutely a 190 steam bath is warmer than a sauna, in terms of heat transfer to the human body, due to density of the water particles.

Just like there's more heat in a 110 degree cup of coffee than there is in a lighted match. The match has more intensity of heat but far less of it (volume).

And yes, just because the ambient air temperature might drop to 30 degrees at sun up, the palm bud might not see that low a temparture due to the fact that it hasn't lost all it's heat (it had going into the night) via conduction and radiation into the ambient air. That's why a simple insulative wrap may be enough during non hard freezes to protect the bud as long as the duration of the freeze isn't too long.

great info there walt on the temps, canopies and proximity of the bud to the ground.  the minimum ambient temps reported by a single thermometer or the weatherman are woefully inadequate for understanding the susceptibilities of palms in places with high overnight temperature transients.  Hopefully more palm growers willuse some of this info to their advantage in keeping healthier palms through the cold stuff.  My alexandrae seedlings are really gowing fast, outstripping my maximas and purpea.  Rapid recovery will be important to me in maintaining beautiful palms.  As per your discussion, I will be using more temp  sensors this winter and will work to better understand ways I can trap my heat from the exhaust vents to locate warm spots and then plant wind blocks to better control the thermals in my future planting areas for kings, royals.

[Bilbo]

I have lent Jones (of Australia) book "Palms throught the world I think) to a friend but unless my memory is playing tricks I think he wrote that the Bangalow was the cold hardier so I shall plant one in the next 12 months when Sue isnt looking.

She discovered my last palm bill and had a fit - even tho all palms are paid for by me out of my own personal a/c with one exception which was when we moved here and I took her to Architectural Palms where she fell for a Brahea armata because it had "a pretty colour."

I shall therefore inform her that the Bangalow has "pretty" lilac flowers that remind me of her.

That should do the trick!

Regardez

Juan

[sunshine]

She discovered my last palm bill and had a fit - even tho all palms are paid for by me out of my own personal a/c with one exception which was when we moved here and I took her to Architectural Palms where she fell for a Brahea armata because it had "a pretty colour."

I shall therefore inform her that the Bangalow has "pretty" lilac flowers that remind me of her.

Might work

[Pivi]

Hi everybody.

I bought one in july this year, about 5 feet overall.

This will be the first winter to test her here on an island in adriatic sea.

[EuroPalm]

Hi Pivi,

What island ?

Phil

[Pivi]

Hi EuroPalm.

Are you in connection with europalm.be site?

I'll order some seeds from them next month...

Island is Vis in Croatia (Dalmatia)

[ruskinPalms]

Went below 32F at 330am, went back above 32F by 830am. 5 total hours of freezing temperatures. Ultimate low of 29.7F with 7.6 "freezing degree hours" calculated as discussed in the weather forum. Moderate winds varying from NNW to NNE all night, dewpoints in low teens, no frost. No overhead canopy in my yard. No protection provided. Photos from 4 days after the freeze event.

North side of house:

[ruskinPalms]

West side:

[STEVE IN SO CAL]

Var. Beatrice

3 plants, 7' OA height

22f, multiple hours and nights below freezing

Defoliated...slowly recovering

[falcon1988]

the palm is maybe 2.5 feet and its not even an year in the ground planted in spring of 08 the 2 nite in the mid 30's

light frost Palm is about 70% leaf burn but there's a new spear opening as i write this when small like this they are very tender to frost

but not to the temperature.

[Keith N Tampa (ex SoJax)]

Here's a soon to be extracted plant exposed to several nights in the mid 20's, some with heavy frost. Pure wimp!

[Rafael]

Hi everybody,

I am a portuguese friend of palms, since I got a new home and needed to buid a landscape.

I have some cocos plumosa, and archontophoenix alexandrae.

The weather here is not so good as in other places in wich you live, but we have temperatures, medium, betwen 5 and 25 degrees.

In Winter, sometimes we have -5 degrees, and this winter we got there, and my specimes became almost totaly burn. Two small have the center burn, and i thing they wont recover, but another bigger has few parte green, however the new part growing is burn at the top. I dont know what to do, must i have some special care? I will wait for the spring effects. I will upload some fotos later

Rafael, from Furadouro, Portugal

[Rafael]

Hi everybody,

I am a portuguese friend of palms, since I got a new home and needed to buid a landscape.

I have some cocos plumosa, and archontophoenix alexandrae.

The weather here is not so good as in other places in wich you live, but we have temperatures, medium, betwen 5 and 25 degrees.

In Winter, sometimes we have -5 degrees, and this winter we got there, and my specimes became almost totaly burn. Two small have the center burn, and i thing they wont recover, but another bigger has few parte green, however the new part growing is burn at the top. I dont know what to do, must i have some special care? I will wait for the spring effects. I will upload some fotos later

Rafael, from Furadouro, Portugal

[Rafael]

this is what i ve talked about

[spockvr6]

Rafael-

Id say your smaller ones are not coming back, but the larger one has a chance.

[Rafael]

Hi everybody, these as those palms i have talked about.

What do you think?

Edited March 12, 2009 by rafael

[Walt]

Hi everybody, these as those palms i have talked about.

What do you think?

I don't know exactly how low a temperature you A. alexandrae saw and for what duration, but I will share this with you.

My A. alexandrae in below photo (with 2.3 meters of trunk) was exposed to a low of 4.6 C. In fact, it saw three back to back nights where the low temperature dropped below 0 C (2.75C, 4.6C, and 2.75C). I don't know what the duration of temperatures were. My low temperature of 4.6C was in the open yard, so my A. alexandrae could have seen a slightly higher temperature. In any event, I believe my palm is fine. Since the freezes of late January, it as shedded two of the lowest frond bases, the last one three days ago, and started opening a new frond yesterday. The new frond looks good.

If your newest spear is growing I believe your palm should be okay, albiet some of the new fronds might have some damage and/or be stunted.

I have many crown shaft palms that were freeze damaged and all seem to be okay. All are starting to shed the oldest frond bases (the bases are spliting from increased diameter growth of the crown shaft) and the new spears are growing and looking fatter.

[gilles06]

Hi Rafael,

Your photo is not good enough to see the 2 small palm trees. Are they syagrus romanzofiana or archontophoenix?

Anyway, you have to use fungicide on your palms and wait for hot temperatures. Don't cut the leaves until summer.

Even the 2 small can regrow, if there is one inch of green...

Hope.

Gilles06.

[epicure3]

Hi Rafael,

Your photo is not good enough to see the 2 small palm trees. Are they syagrus romanzofiana or archontophoenix?

Anyway, you have to use fungicide on your palms and wait for hot temperatures. Don't cut the leaves until summer.

Even the 2 small can regrow, if there is one inch of green...

Hope.

Gilles06.

They are indeed Archotophoenix. Queen palms. and all Syagrus species, are non crown shafted palms. Good advice on the after freeze care.

[Rafael]

Hi, yes they are all archontophoenix alexandrae, and the smaller two have no inch of green on the new spear. I think they wont recover at all. And the new spear of the big one is parcialy damaged at the top. Will ir recover? And what kind of fungicide are you talking about? Thank u for your simpaty.

[Rafael]

Hi again, here there are some photos of the bigger alexandrae palm. What do you think? Will it recover? As you see the most recent spear is parcialy damaged. I do not know if there is any chance at all. Could that spear grow? And if not, could another spear appear?

Edited March 15, 2009 by rafael

[Rafael]

Hi again, here there are some photos of the bigger alexandrae palm. What do you think? Will it recover? As you see the most recent spear is parcialy damaged. I do not know if there is any chance at all. Could that spear grow? And if not, could another spear appear?

Edited March 15, 2009 by rafael

[peachy]

Hi everybody,

I am a portuguese friend of palms, since I got a new home and needed to buid a landscape.

I have some cocos plumosa, and archontophoenix alexandrae.

The weather here is not so good as in other places in wich you live, but we have temperatures, medium, betwen 5 and 25 degrees.

In Winter, sometimes we have -5 degrees, and this winter we got there, and my specimes became almost totaly burn. Two small have the center burn, and i thing they wont recover, but another bigger has few parte green, however the new part growing is burn at the top. I dont know what to do, must i have some special care? I will wait for the spring effects. I will upload some fotos later

Rafael, from Furadouro, Portugal

Hi Rafael....I live in Queensland Australia, where the archontophoenix palms come from and I saw your photos of the small burnt palms. Leave them alone, dead fronds and everything, and they should be back to normal in 6 months. Going by the photo of your garden and the local cimate there, alexandrae were not a good choice. They prefer a humid subtropical climate. Archontophoenix Cunninghamia look very similar to Alexandrae but would really thive in your climate. They would survive a frost of minus 5 with very little (if any at all) damage. They are also faster growing. Even big Alexandrae will get frost damaged so it could be an ongoing problem for you. When you are certain the frosts are finished for the year, feed the palms well and also give them good doses of seaweed mixture until at least one new leaf spear is formed.

Good Luck,

Peachy<

Qld Australia

[Rafael]

Peachy, hi and thanks about your advisements concerning archontophoenix alexandrae. The two small are already gone, replaced by two beautiful and big syagrus. The bigger one changed its place, with less wind exposure, and now, with copper and feed. But i am still thinking about hidrogen peroxid. What do u think? And what kind of seaweed mixture are you talking about? Anyway, the new leaf spear, damaged at its top, is trying to become green at its base. Concerning to the weather here, the temperatures change between -4 and 15, in winter, and 8 and 30 in the rest of the year. This winter was on of the worsts since people talk about it, and i think if i can protect the fronds, by closing them to the winds and freeze, i wont have those ongoing problems. What do you yhink? Anyway I will check those cunninghamia, thanks.

[Rafael]

All the palms that were damaged did die, unfortunately, in April.

In May i bought a bigger archontophoenix alexandrae (30 cm trunked/base and 4,5 m tall), wich i show on this photo. I am still looking for one archontophoenix cunnighamiana (not easily found here)

Well, here we have maybe 10/20 frost nights a year. Half of them the lower temperature raise -4 C.

I think this one will face frost strongly.

However i wonder if we can do anything to face the frost, concerning to a big palm like this.

Does anyone knows any method to face this problem.

SOS, frost is coming in about 15 days!!!

[osideterry]

Hi Rafael - In our worst freeze in 2007, I protected a number of palms similar in size to your A. alexandrae by wrapping the crownshaft area in multiple layers of burlap material, and tied with bungee cord. I lost a lot of foliage but all palms bounced back from seeing lows of 25-29F several nights in a row. I did not have a large Alex' at the time, but did see A. cunninghamiana, Royal, Caryota obtusa and urens, recover without any problem.

Another member here wrapped the growth area with rolls of leftover carpet. I wouldn't try to throw a sheet over an entire palm. Too hard to pull off and you might damage a new spear.

[Walt]

Rafael: If you get frost then that indicates to me that your freezes aren't advective (windy). If that's the case, I would saturate the soil around your palm the morning before the night of the upcoming freeze so that the soil can absorb the sun's radiant heat (all day long, providing it's not a cloudy day) and re release it at night, keeping the air around your palm maybe a degree or two warmer. Wet soil can hold more heat than dry soil, so that is the physics here. Of course, if it's windy than wet soil isn't going to do you any good. In fact, it could actually hurt due to evaporative cooling effect.

In any event, I would advise you to either procure some heating cables (the type outdoor water pipes are wrapped with, plus pipe insulation) or some good outdoor string lights (that give off heat) and wrap the trunk and crown shaft with them, then wrap over the cables/lights with a blanket or equivalent, so as to hold in the heat. However, I would first wrap the crown shaft with a terry cloth towel, then wrap the cables/lights over the towel, as sometimes the lights/cables can sear the delicate crown shaft tissue.

I would only advise the above method when temperatures drop below 0C/32F, or close to it, as your palm most likely will be okay.

I executed the above method last January when my low temperature dropped to almost -5C. While the fronds got fried, the trunk, crown shaft and growth bud was not subjected to such a cold temperature, hence the palm recovered quite well, as the below photos atest.

One of my Archontophoenix alexandrae palms near my house. Note the heating cables and insulation (flannel sheet) wrapped around the crown shaft. This photo was taken about two weeks after the freeze, in preparation of another cold night, and you can see all the dead frond leaves from the January freezes, plus a new spear that is opening.

My Archontophoenix alexandrae about 75% recovered. It still needs to regrow several more fronds for a full canopy.