Which archontophoenix?

[Sandy Loam]

Which of these two archontophoenix will grow taller and which one is more cold hardy? : Alexandrae or Cunninghamiana

 

1.   If cunningham is more cold-hardy than Alexandrae, isn't it an extremely marginal difference (too minimal to worry about) 

2.   Sources say that Alexandrae will grow to 100 feet, whereas cunningham will only grow 40-60 feet.  That is double the size, but aren't those stats taken from natural habitats in Australia after 100 years of growth?   The reality of street plantings is that both palms end up being similar in height after twenty years and then slow down to an almost maxxed out height.  Is that not correct?  Please correct me if I am wrong.  

 

I was under the impression that these two palms are just barely distinguishable, but perhaps I am mistaken. I look forward to your thought. Thank you in advance. 

[65Pedro]

3 hours ago, Sandy Loam said:

Which of these two archontophoenix will grow taller and which one is more cold hardy? : Alexandrae or Cunninghamiana

 

1.   If cunningham is more cold-hardy than Alexandrae, isn't it an extremely marginal difference (too minimal to worry about) 

2.   Sources say that Alexandrae will grow to 100 feet, whereas cunningham will only grow 40-60 feet.  That is double the size, but aren't those stats taken from natural habitats in Australia after 100 years of growth?   The reality of street plantings is that both palms end up being similar in height after twenty years and then slow down to an almost maxxed out height.  Is that not correct?  Please correct me if I am wrong.  

 

I was under the impression that these two palms are just barely distinguishable, but perhaps I am mistaken. I look forward to your thought. Thank you in advance. 

Hi there in Florida.

As an Aussie, Cunninghamiana are stunning in  VAST numbers in a Rain forest setting. Archontophoenix Alexandrae and all it's siblings bar Bangalow/ Cunninghamiana ( King Palm called in the 
 US for "some reason"🤷‍♂️🤷‍♂️ ALL have Silver under the leaflets and the Fronds/ Leaves are held quite flat. Bangalows hold their Fronds/ leaves on a slant. More study NEEDS to be done as Bangalows I've seen out West in a National Park are Massive and hold their Fronds/Leaves flat, Re Aleaxandrae getting to 100ft in 100 yrs =NO. I have an Archo var that thit the 100 ft mark in less than 20 yrs with a mtr wide base. In Australia MOST Archontontophoenix  BAR Bangalow are simply called Alexanders. In Full Sun Alexanders FAR outperform Bangalows.
I hope this helps you.ps On the Archontophoenix spon Palpedia it shows a boot near 1 of my Maxima's  NOT Cunninghamiana.😂 Alexananders CAN take as much cold as Bangalows 100%.

Happy Gardening.
Pete.

[sonoranfans]

I cant speak personally for bangalows in my yard as I dont have any, but those around my area are less robust(thinner trunk, crown) than my alexanders or maxima.  My alexanders were covered with frost cloth in 2010 dec freeze frost at 28F.  I doubt they saw 28F under a frostcloth.  Some leaves were not quite under the cloth and were fried.   I would expect that in optimal conditions as in frost free parts of Australia they will grow larger than here in florida 10a.9b.  In 12 years, my alexandre triple has gone from 1 gallon size to 15-17' clear trunk.  I did notice that ring spacing increased when I moved back 4 years ago and started adding more supplemental water.   Maxima was planted 3 years after the alex and is closing in with 12' trunk while myolensis planted at the same time as the alexandre is about 10' trunk.  Purpurea has been slower than the others but its in mostly shade.  My yard is bunched with 20'+ palms so this limits th  e possibility of frost in most areas.  I live the silver undersides in bright sun with the wind blowing to expose them.  Others on palm talk as I recall have reported that the bangalows are less sensitive to frost burn and perhaps a few degrees more cold hardy.  Not sure about winter haven but canopy may be needed for any of these to survive long term in 9b.  

[ruskinPalms]

I’ve tried both alexandrae and cunninghamiana in borderline 9B/10A Florida and I do thing they are beautiful palms that definitely look different to me. Cunninghamiana have more relaxed fronds and the alexandrae have more upright fronds with silver undersides. Unfortunately at two homes between Ruskin and Parrish Florida I have not had much luck with cunninghamiana over the years. They do not like being in full sun here, leaves seem to burn and never look great for long. They probably are a degree or 2 Fahrenheit more cold hardy than alexandrae but they always seem to succumb to some sort of rot after a while. I only ever tried alexandrae at my house in Ruskin but it was by far more robust, faster growing and better suited to a full sun environment in my area than cunninghamiana. My house in Ruskin was very prone to getting frozen dew all over my palms because it was on a retention pond that puffed out plenty of steam on cold nights that tended to freeze to fronds and wreak havoc on nights in the mid to upper 30s  Fahrenheit. Both the cunninghamiana and alexandrae took similar amounts of damage but the alexandrae recovered way faster the following warm season. Fast forward to my current home in Parrish which may get a degree colder than my house did in Ruskin on cold nights but essentially has no frost or frozen dew except for on cars and rooftops on the coldest nights for some reason (not on a retention pond anymore?). I’ve only tried cunninghamiana here and did get one to about 4 feet of trunk and flowering age before it ultimately got pink rot and croaked. It just wasn’t very well suited for my yard which has zero canopy. It always got sun burned and literally seemed to take just as much if not more cold damage on its fronds than an Adonidia planted not more than 20 feet away from it out in the open as well. There is a larger alexandrae completely out in the open about a block away from me that just had a little frond damage from the January 2018 freeze here which was probably 27 to 28 F with wind. My cunninghamiana actually looked worse than the alexandrae after that freeze. So long story short: unless you have high oak canopy to plant under, don’t bother with cunninghamiana in central Florida and go straight to alexandrae if you can find them. I think the sensational stories of cunninghamiana’s cold hardiness come from one’s growing in California which is way different than here or ones growing under high oak canopy here in Florida. They are both beautiful in different ways but I think I’d give alexandrae the nod on appearance anyway.

[sonoranfans]

I second the fast recovery of alexanders.  Mine were defoliated completely save the spears in the 2018 polar vortex advective event at 30F for 5+ hrs but they recovered quickly the next summer.  Advective events might be a problem for these if it gets colder than 30F.  Radiational events give lower temperatures generally here but at 15' above the ground the bud can be 6-8F warmer so the bud doesnt get frozen.   We have a windows in time till palms get tall enough to benefit from that radiative warmth at height.  Even royals here need that height before say a 20 or 30 year cold event (as in 2010) can hit.

[redant]

Neither will do well in Winter Haven unless u have an awesome micro climate.

Edited February 25, 2023 by redant

[kinzyjr]

@Sandy Loam

Both do fine here in Lakeland.  Archontophoenix alexandrae are heavily used in the landscape of Hollis Gardens.  Archontophoenix cunninghamiana are used as a street tree along Main St. and adorn various buildings like the new Summit Holdings Tower, Mass Market, etc.

[Sandy Loam]

1 minute ago, kinzyjr said:

@Sandy Loam

Both do fine here in Lakeland.  Archontophoenix alexandrae are heavily used in the landscape of Hollis Gardens.  Archontophoenix cunninghamiana are used as a street tree along Main St. and adorn various buildings like the new Summit Holdings Tower, Mass Market, etc.

Thank you, Kinzy Jr.   Lakeland is just west of Winter Haven where my house is located, but I'm told that I have a warmer microclimate than Lakeland because my house is basically on the edge of a lake within the Chain of Lakes district. I am advised I am likely in zone 10a, even though appears as Zone 9B on the official USDA map. I don't know if that's true or not because I haven't planted anything yet and am new in town. 

 

It certainly not a Zone 12b climate like Key West or honolulu, but maybe I will be able to get away with some Alexander Palms in the sunny areas and Cunningham Palms in the shady areas of my lot. Downtown Winter Haven seems to be decorated with foxtail palms which do you fine in winter there, and those may be even less cold hardy as bangalows (??) 

 

Thanks to everyone else for your extremely helpful remarks here in this post. If anyone else wishes to comment, please do not hesitate to do so because this is all great information to have. Thank you!

[Sandy Loam]

10 hours ago, ruskinPalms said:

I’ve tried both alexandrae and cunninghamiana in borderline 9B/10A Florida and I do thing they are beautiful palms that definitely look different to me. Cunninghamiana have more relaxed fronds and the alexandrae have more upright fronds with silver undersides. Unfortunately at two homes between Ruskin and Parrish Florida I have not had much luck with cunninghamiana over the years. They do not like being in full sun here, leaves seem to burn and never look great for long. They probably are a degree or 2 Fahrenheit more cold hardy than alexandrae but they always seem to succumb to some sort of rot after a while. I only ever tried alexandrae at my house in Ruskin but it was by far more robust, faster growing and better suited to a full sun environment in my area than cunninghamiana. My house in Ruskin was very prone to getting frozen dew all over my palms because it was on a retention pond that puffed out plenty of steam on cold nights that tended to freeze to fronds and wreak havoc on nights in the mid to upper 30s  Fahrenheit. Both the cunninghamiana and alexandrae took similar amounts of damage but the alexandrae recovered way faster the following warm season. Fast forward to my current home in Parrish which may get a degree colder than my house did in Ruskin on cold nights but essentially has no frost or frozen dew except for on cars and rooftops on the coldest nights for some reason (not on a retention pond anymore?). I’ve only tried cunninghamiana here and did get one to about 4 feet of trunk and flowering age before it ultimately got pink rot and croaked. It just wasn’t very well suited for my yard which has zero canopy. It always got sun burned and literally seemed to take just as much if not more cold damage on its fronds than an Adonidia planted not more than 20 feet away from it out in the open as well. There is a larger alexandrae completely out in the open about a block away from me that just had a little frond damage from the January 2018 freeze here which was probably 27 to 28 F with wind. My cunninghamiana actually looked worse than the alexandrae after that freeze. So long story short: unless you have high oak canopy to plant under, don’t bother with cunninghamiana in central Florida and go straight to alexandrae if you can find them. I think the sensational stories of cunninghamiana’s cold hardiness come from one’s growing in California which is way different than here or ones growing under high oak canopy here in Florida. They are both beautiful in different ways but I think I’d give alexandrae the nod on appearance anyway.

 

Thank you Ruskin.  The pink rot or other rot news does not bode well for archontophoenix cunninghamiana in our rainy, humid climate.   Did you ever have problems with archontophoenix alexandrea succumbing to any kind of rot?  Did anyone else here have "rot issues" with alexandrea, or only with cunninghamiana?

 

[ruskinPalms]

I only had trouble with the cunninghamiana. They were much slower for me than alexandrae and I’ve come to find that most slow 10A+ palms I’ve tried around here seem to be more susceptible to rot and other diseases especially after they’ve slowed down even more in winter heading into spring. 

[Sandy Loam]

Thanks to everyone who posted here.  These comments have led me to a few additional questions, namely:

1.  Are the fronds longer on archontophoenix alexandrae when compared with cunninghamiana? If so, is it only a minor difference? 

2.  The trunk appears to be wider on alexandrea than on cunninghamiana in photos, which usually implies taller growth.  Pete, I love that your Alexander palm hit 100 feet in height after 20 years.  Fantastic!  Is it fair to guess that a bangalow could never do that? 

3.  SHADE:  I have some shady spots and some sunny spots for planting. Was it implied in the answers above that cunninghamiana perform better in shade than alexandrae?  Will Archontophoenix Alexandrea grow slowly in shade?   A. Cunninghamiana are known to be fast growers in shade when compared with other palms, some of will hardly grow at all in shade.  

4.   Someone here mentioned Maxima.   I had not even considered archontophoenix maxima because I would not even know where to buy that species.  Nonetheless, aren't A. Maxima leaves extremely long?  I have some power lines near my house and  palm with long fronds might eventually reach out and touch them.  Bangalow (cunninghamiana) likely wouldn't reach out that far, based on my recollection of them.   

5.  Do Archontophoenix grow more vigorously or taller than Archontophoenix Alexandrae?  The name "Maxima" implies something, but I am not sure what. 

6.  Are archontophoenix maxima more cold-hardy than cunninghamiana and alexandrae, or less? .....or roughly the same?  I definitely can't go with anything LESS cold-hardy than cunninghamiana or else I will regret it once every five years when a polar vortex strikes. 

7.  I must admit that I prefer the drooping "umbrella" shape of Archontophoenix Cunninghamiana over the more upright near-shuttlecock shape of the Alexandrae, but I need palms that will tolerate a lot of rain without rotting.  Is A. Maxima susceptible to rot as well?  I could be wrong, but photos of A. Maxima make its fronds appear somewhere in between the drooping Cunninghamiana shape and the more rigid Alexandrae shape.    

   

Thank you in advance for all of your answers!  

 

[James B]

Maxima refers to its inflorescence. But even that’s variable. I think the biggest issue is even professional growers mix up seeds and mislabel palms in the Alexandrae complex and people have palms they think are one subspecies but are really something else.

The best resource are Australian PT members who live in the areas where Archontophoenix grows as they can give local insight for their native palms. Based on what I’ve read from them they concur that the largest A.Maxima on average will be larger than Alexandrae but there is enough variation that a genetic freak Alex can be bigger than most Maxima.

As for leaves: Cunninghamiana has two subtypes and the more robust type has the largest leaves of all the Kings up to a certain height. It has a massive robust crownshaft much larger in girth than the others and almost resembles a giant Rhopalostylis.

In terms of maximum height in Socal. The tallest Cunninghamiana I’ve seen don’t get above 40 feet whereas at the San Diego zoo they have a large cluster of both Cunninghamiana and Alexandrae and the tallest Alex is over 60 feet and towers over the Cunninghamiana. Now maybe they are older I can’t speak to that but they are much taller and have much fatter bases up to about 3-4 feet above ground then they taper and there isn’t much difference. 

[James B]

Florida seems to cause different growth patterns than Socal.

I would say A.Tuckeri is another subtype to try. It’s very underrated and flies under the radar but it grows super fast and it also gets a very robust trunk base which is usually more roundish in shape and less stepped than Alexandrae or Maxima. Fellow Floridians May be able to chime in on Tuckeri results in their gardens.

[65Pedro]

31 minutes ago, James B said:

Maxima refers to its inflorescence. But even that’s variable. I think the biggest issue is even professional growers mix up seeds and mislabel palms in the Alexandrae complex and people have palms they think are one subspecies but are really something else.

The best resource are Australian PT members who live in the areas where Archontophoenix grows as they can give local insight for their native palms. Based on what I’ve read from them they concur that the largest A.Maxima on average will be larger than Alexandrae but there is enough variation that a genetic freak Alex can be bigger than most Maxima.

As for leaves: Cunninghamiana has two subtypes and the more robust type has the largest leaves of all the Kings up to a certain height. It has a massive robust crownshaft much larger in girth than the others and almost resembles a giant Rhopalostylis.

In terms of maximum height in Socal. The tallest Cunninghamiana I’ve seen don’t get above 40 feet whereas at the San Diego zoo they have a large cluster of both Cunninghamiana and Alexandrae and the tallest Alex is over 60 feet and towers over the Cunninghamiana. Now maybe they are older I can’t speak to that but they are much taller and have much fatter bases up to about 3-4 feet above ground then they taper and there isn’t much difference. 

Your spot on Re Maxima James. Many "think" by its name it's the largest BUT as you wrote it has the largest Peduncle.

Re Freaks . This Alexander here at Far Nth NSW we built a deck around is "over" 100ft tall and under the deck its base is a good mtr wide.

Ed put this pic in the Cunninghamiana section on Palmpedia.

Also James there are MANY different types of Bangalows, more than 2. Living were there are large populations and in people's gardens, street  plantings etc I've seen MANY 

different forms.  Some holding ALL their Fronds at a 45 deg angle. HOW they got called "King Palms" is hard to fathom.

As you mentioned James, Florida's climate is like chalk n cheese in the 1 state.

IF I lived in the US and was KEEN AS into Palms I'd move to Hawaii.

To me the Most Stunning of all Archo's is Purpurea, and to get BEST Colour grow in FULL SUN as long as ALWAYS Moist.

[James B]

Doesn’t surprise me to hear there are more than 2 types of Bangalows. 
 

I like the purple hue of Purpurea for uniqueness but for me Myolensis or the Maximas that also showcase that green emerald waxy crown shape are my personal favs. 
 

As an Archontophoenix enthusiast I want all of them in my garden so I can enjoy them ha!

[Sandy Loam]

On 2/25/2023 at 1:01 PM, redant said:

Neither will do well in Winter Haven unless u have an awesome micro climate.

oooh.  Ok.  That's not good news, I guess.   

Redant, you appear to be in Jupiter, FL which doesn't get the occasional cold snaps that we see up here in Winter Haven.   Surely all type of archontophoenix do well in coastal Jupiter, Florida, don't they?  I once stayed at a beach hotel in Jupiter and it was surrounded by old, mature coconut palms and I think some veitchias as well --- all palms which are more cold-sensitive than archontophoenix, I believe. 

Edited February 26, 2023 by Sandy Loam

[Sandy Loam]

17 hours ago, 65Pedro said:

Your spot on Re Maxima James. Many "think" by its name it's the largest BUT as you wrote it has the largest Peduncle.

Re Freaks . This Alexander here at Far Nth NSW we built a deck around is "over" 100ft tall and under the deck its base is a good mtr wide.

Ed put this pic in the Cunninghamiana section on Palmpedia.

Also James there are MANY different types of Bangalows, more than 2. Living were there are large populations and in people's gardens, street  plantings etc I've seen MANY 

different forms.  Some holding ALL their Fronds at a 45 deg angle. HOW they got called "King Palms" is hard to fathom.

As you mentioned James, Florida's climate is like chalk n cheese in the 1 state.

IF I lived in the US and was KEEN AS into Palms I'd move to Hawaii.

To me the Most Stunning of all Archo's is Purpurea, and to get BEST Colour grow in FULL SUN as long as ALWAYS Moist.

 

Pedro, thank you.   This is fantastic information to have.  I appreciate you posting it.   

I just googled your favourite, Archontophoenix Purpurea.  I love it!  The crownshaft shape is more elegant than cunninghamiana or alexandrae.   The crownshaft is nice too, but I don't really care as much about that.  Do A. Purpurea grow as vigorously as A. Alexandrea in a wet, humid climate?  What about shade-grown A. Purpurea?  I wish I could tell you what my soil type is, but I am still new to this property and haven't figured out those details yet.   

[Anyone else, please feel free to chime in]

I agree that it's hard to compare the climate of Florida to Australia's where archontophoenix are native and 'supposed' to be.   I also agree with you about Hawaii, although I keep wondering whether there are other contender palm climates in the US such as Guam, Puerto Rico, Marshall Islands, US Virgin Islands, American Samoa, etc.   Here in Florida, Key West is the best climate for growing palms because it is constantly humid, sunny and almost never gets chilly ---- perhaps similar to the climate in Rockhampton, Qld or Townsville, Qld (???), but I'm not sure.   I hear that one could even grow a delicate pigafetta down in Key West.  

 

Thank you for your very instructive comments. 

[Sandy Loam]

17 hours ago, James B said:

Doesn’t surprise me to hear there are more than 2 types of Bangalows. 
 

I like the purple hue of Purpurea for uniqueness but for me Myolensis or the Maximas that also showcase that green emerald waxy crown shape are my personal favs. 
 

As an Archontophoenix enthusiast I want all of them in my garden so I can enjoy them ha!

Hello James.  I just googled Myolensis.  Wow, the fronds are very arched in the umbella shape of a typical bangalow/King Palm.   Do you know anything about its growth rate? 

Having just googled A. Purpurea as well, I am suddenly in love with its crownshaft shape, but I have no idea how cold-hard it is, whether it is as fast-growing as A. Alexandrae, and whether I could even find any for sale here in Florida (including South Florida where many nurseries and growers are located).   Palmpedia suggests that A. Purpurea won't grow as tall as A. Alexandrae, and it contains no info about the height of Myolensis at all. 

Thanks for your input and everyone else's here.  

 

[James B]

Myolensis will stick out vs Cunninghamiana. You’d have to see them in person side by side but the difference is quite a bit. The crown shaft color is the best thing about it. Some people here in Socal have specimens that are very impressive. Can’t speak to Florida but Purpurea looks better in shade where I am due to the dry heat.

[Sandy Loam]

CONTINUED:   I was just reading somewhere else that Archontophoenix Purpurea will not do well in full sun in Florida.  It is for shade only in this climate, according to those sources.  I don't know whether that is accurate information or not.  If so, it's a pity because Purpurea appears to be a truly stunning palm, based on photos alone.  Maybe that rule only applies to young specimens, but I can't cover palms in shade cloth for the first five years.  If I can find any A. Purpurea for sale in Florida, I will simply plant them in shady spots.

I am still not sure if I can even grow Archontophoenix long-term in this climate where my new house is located (among the Chain of Lakes district in Winter Haven, FL).  I see some mature Roystonia Regia (royal palms) here, some mature foxtail palms, mature Areca palms and others, so I hope that Archontophoenix would do well enough in this climate.  If once every five years, a cold snap turns the fronds brown for a couple of months, I'm ok with that.  I just don't want to be looking at brown/toasted fronds every single winter.   The dramatic cold snaps tend to happen once every five years and last 3-4 days.  

Last question:  Who sells A. Purpurea in Florida?  I will look for some Archontophoenix Alexandrae too, but they should be easier to find --- I hope. 

[Sandy Loam]

1 minute ago, James B said:

Myolensis will stick out vs Cunninghamiana. You’d have to see them in person side by side but the difference is quite a bit. The crown shaft color is the best thing about it. Some people here in Socal have specimens that are very impressive. Can’t speak to Florida but Purpurea looks better in shade where I am due to the dry heat.

 

Thank you!  Are the Myolensis fronds quite long?  One of my planting locations isn't too far from some powerlines.   In that site, I can plant the trunk no more than 3 metres/yards away from the power lines.   Thanks James!

 

[redant]

3 hours ago, Sandy Loam said:

oooh.  Ok.  That's not good news, I guess.   

Redant, you appear to be in Jupiter, FL which doesn't get the occasional cold snaps that we see up here in Winter Haven.   Surely all type of archontophoenix do well in coastal Jupiter, Florida, don't they?  I once stayed at a beach hotel in Jupiter and it was surrounded by old, mature coconut palms and I think some veitchias as well --- all palms which are more cold-sensitive than archontophoenix, I believe. 

We are a far better climate then where you are. I have a camp in Polk county, no way a King will grow there.  We have been very lucy since the 09/10 cold which killed most of my coconuts.

[redant]

2 hours ago, Sandy Loam said:

CONTINUED:   I was just reading somewhere else that Archontophoenix Purpurea will not do well in full sun in Florida.  It is for shade only in this climate, according to those sources.  I don't know whether that is accurate information or not.  If so, it's a pity because Purpurea appears to be a truly stunning palm, based on photos alone.  Maybe that rule only applies to young specimens, but I can't cover palms in shade cloth for the first five years.  If I can find any A. Purpurea for sale in Florida, I will simply plant them in shady spots.

I am still not sure if I can even grow Archontophoenix long-term in this climate where my new house is located (among the Chain of Lakes district in Winter Haven, FL).  I see some mature Roystonia Regia (royal palms) here, some mature foxtail palms, mature Areca palms and others, so I hope that Archontophoenix would do well enough in this climate.  If once every five years, a cold snap turns the fronds brown for a couple of months, I'm ok with that.  I just don't want to be looking at brown/toasted fronds every single winter.   The dramatic cold snaps tend to happen once every five years and last 3-4 days.  

Last question:  Who sells A. Purpurea in Florida?  I will look for some Archontophoenix Alexandrae too, but they should be easier to find --- I hope. 

Archontophoenix Purpurea is very difficult in FL and will never exhibit a purple crown shaft. try these easier kings.

[kinzyjr]

22 hours ago, Sandy Loam said:

SHADE:  I have some shady spots and some sunny spots for planting. Was it implied in the answers above that cunninghamiana perform better in shade than alexandrae?  Will Archontophoenix Alexandrea grow slowly in shade?   A. Cunninghamiana are known to be fast growers in shade when compared with other palms, some of will hardly grow at all in shade.

My garden currently has Archontophoenix alexandrae, Archontophoenix cunninghamiana, and Archontophoenix purpurea.  All of these are grown in dappled light most of the day and grow relatively well under those conditions.  They are concentrated in the lower part of the property where all of the run-off eventually ends up since they love moisture.

In regard to each species cold tolerance, it is going to depend on what benchmark you set for your particular garden. 

The record low combining the data from NOAA stations at the airport (KGIF) [USW00012876] and another station in the middle of town [USC00089707] is 19F.  The stations have records from 02/10/1941 to present as of this post.  If you want palms that will survive record lows, then Archontophoenix is a poor choice.

If your benchmark is surviving both January 2010 and December 2010, the palms in front of Lakeland City Hall survived those freezes.  My recommendation for deciding on them in terms of cold tolerance is to review the data available in the Cold Hardiness Master Data for the Archontophoenix genus in areas along the I-4 Corridor and interior Florida (Daytona, Orlando, Maitland, Oviedo, Lakeland, Winter Haven, Sebring, Brandon, Tampa) and decide based on whether the results are within your personal limits for risk.  Most palms tend to bounce back from lower temperatures in drier climates, so it helps to limit the search to applicable regions.

I'd also recommend reviewing the NALs sheet (NOAA Annual Lows) for the Winter Haven NOAA stations I listed above in the Florida Freeze and Weather Station Data spreadsheet to see how often it gets how low.  If you'd rather have a quick snapshot than a table of weather data, the links to the Google Maps showing the temperatures during each of Florida's impact freezes are copied and posted here from the Florida Freeze and Weather Station Data thread above:

Florida Impact Freezes 00 (1835-1977): https://www.google.com/maps/d/edit?mid=18H1cufNcjuFbcjZEkhaOPAxwazmWVGc&usp=sharing
Florida Impact Freezes 01 (1981-2022): https://www.google.com/maps/d/edit?mid=1h2lbBtHdxlGNuyDTVo5A6xdrn4McSCQ&usp=sharing

[Fishinsteeg234]

@Sandy Loam I recommend taking a day trip to Leu Gardens in Orlando just a bit north of you to view and observe successful growing conditions for Archontophoenix (and many other zone 10 palms) in a 9B microclimate, similar to your area. You’re going to want to position yours under a dappled shade canopy, with plenty of water. If your yard can supply 50’+ Oak canopy, Archontophoenix can eventually reach it with the right conditions.

 

[Tyrone]

Archontophoenix myolensis can get a light aqua blue crownshaft. That's what some of mine are doing now.

Asking about speed of growth comparisons depends on how heat deprived your climate is. If you are heat deprived, like southern coastal WA, Gippsland in Victoria, NZ, or coastal Northern California, cunninghamiana is about double the speed of alexandrae, and the others. If you have good year round warmth, they will all grow about the same speed except for purpurea which is the stalactite of the genus, but by no means the slowest palm on Earth, and really beautiful and distinct.

Looking at where each species come from in the wild, ie latitude versus altitude from most tropical to least tropical, Archontophoenix will look like this. A tuckeri, A alexandrae, A myolensis, A maxima, A purpurea, and least tropical in requirements A cunninghamiana. In the middle there is almost no difference as they are all mountain palms, and even alexandrae has mountain habitats too. High altitude versions of cunninghamiana will be the most cold tolerant, not the most southern populations, as they are often near the coast which rarely gets to freezing temps if ever. 

All Archontophoenix needs copious moisture. They grow along streams. They won't get to any extraordinary size without it. If you find they are rotting something else is going on. They are water hogs, although cold and wet for too long are not what they like either. 

[tim_brissy_13]

18 hours ago, Tyrone said:

Archontophoenix myolensis can get a light aqua blue crownshaft. That's what some of mine are doing now.

Got any photos Tyrone? I’m seeing hints of colour in mine now (8 years old from seed). 

[tim_brissy_13]

On 2/27/2023 at 6:57 AM, James B said:

Myolensis will stick out vs Cunninghamiana. You’d have to see them in person side by side but the difference is quite a bit. The crown shaft color is the best thing about it. Some people here in Socal have specimens that are very impressive. Can’t speak to Florida but Purpurea looks better in shade where I am due to the dry heat.

Yes very different to look at. I’ve grown them all so I’ll add my input for a visual key for the different species, without reference to flowers/fruit/seed differences which probably aren’t visually obvious from a distance and therefore less useful to general enthusiasts (and not useful at all for juveniles). 
 

General comments: 

- I’ve seen no distinctive differences in overall size between any of the species  The variability within each species overlaps with all others.

- Grown rate: Highly variable depending on sun/shade, soil, water and climate.  A cunninghamiana is the fastest for me, but I’m in a relatively cool climate.  My specimen in part shade and rich soil doubles to rate of another in full afternoon sun with root competition. A. purpurea generally the slowest regardless of conditions and climate.

A. purpurea

The most distinctive species.  The only species with silver frond underside AND ramenta (little hairy things) on the leaflet undersides.  Even seedlings are distinctive; they tend to hold onto bogus fronds longer and have a bright yellow colour to leaf bases.  As they mature they develop the unique purple/blue crownshaft they are known for.  Freshly exposed trunk will generally be a bright aqua colour for one/two growth rings and eventually fade to brown. Occasionally freshly exposed growth rings with be covered in a dense dark coloured wooly material. Will never throw coloured new fronds from my experience. Sun grown specimens will have relatively upright fronds. Fronds and leaflets tend to be quite stiff/thick to the feel relative to other species.

 

A. cunninghamiana

The second most distinctive species. The only species will green frond undersides. Has ramenta on leaflet undersides.  Crownshaft colour can range from olive green to purplish from a distance, but never brightly coloured.  If you look closely at the crown shaft, it will be covered in brownish speckled material. Freshly exposed growth rings nearly always are brown straight away just as for the mature trunk. Fronds twist 90 degrees to the vertical at the end of fronds. Size is highly variable, some specimens end up huge, others much smaller and thinner. This seems to depend on growing conditions and origin of seed.  Trunk with start quite thin when at a young age and generally swell as they gain height  all other species tend to get a bit more ‘chunky’ before exposing clear trunk. Can occasionally throw slight reddish new fronds, most likely in the cooler months for me (but not all specimens).

A. myolensis

 Silver frond undersides, no ramenta. Crownshaft colour ranges from bright emerald green to aqua blue. Fronds twist 90 degrees (like A. cunninghamiana).  Leaflets tend to be the widest of all species (just my observation, I don’t think this is formally documented).  Usually not likely to throw new coloured fronds. Freshly exposed trunk is green, fading to brown over time.
 

A. maxima

Silver frond underside, although maybe more dull/grey in appearance than myolensis, tuckeri, purpurea and alexandrae.  Specimens grown in full sun have little to no petiole; leaflets will start at the leaf base.  Unfortunately this trait doesn’t seem to occur on shade grown specimens making them difficult to ID.  Crownshaft colour ranges from emerald green to aqua blue like myolensis but usually perhaps not quite as vibrant as myolensis (although variable). Sun grown specimens tend to have quite upright fronds. Shade grown and more relaxed. Generally minimal frond twist. Will sometime throw a reddish new frond. Freshly exposed trunk is generally green fading to brown over time.

 

A. alexandrae

Silver frond undersides, no ramenta. Fronds similar to A. maxima; more upright in sun, relaxed in shade, generally no twist. Usually distinctive by crownshaft colour; typically has some white/silver colouration which is more prominent in sun grown specimens (more towards a flat green colour in the shade).  Will sometime throw a reddish new frond. Freshly exposed trunk is generally green fading to brown over time.
 

A. tuckeri

Silver frond underside, no ramenta.  Generally some frond twist although generally not 90 degrees. Crownshaft colour always quite bright emerald green. Freshly exposed trunk green fading to brown over time. Very commonly throws a reddish new leaf and can be quite bright red in some specimens.

 

It’s probably obvious from the above, but A. myolensis, maxima and tuckeri (and even alexandrae) can be quite difficult to tell apart in certain conditions, especially for juvenile specimens. Throw into the mix that hybrids exist, and the genus can be a difficult one to distinguish separate species. FYI the alexandrae x cunninghamiana (or reverse) hybrid generally looks like alexandrae but with the brownish speckles on the crownshaft.

Some photos to come…

 

[tim_brissy_13]

A. myolensis:

[tim_brissy_13]

A cunninghamiana (triple planted) - poking above the garden in the first photo:

[tim_brissy_13]

A purpurea

Further to the above, petioles tend to be yellowish and leaflets are generally strongly folded especially close to the rachis.

[tim_brissy_13]

A. tuckeri (not the best photo):

[tim_brissy_13]

A maxima

[tim_brissy_13]

A alexandrae

 

[tim_brissy_13]

A cunninghamiana x alexandrae 

[tim_brissy_13]

Finally, an A myolensis at Gardens by the Bay in Singapore. The crownshaft colour has to be seen to be believed, I couldn’t capture it in the photo:

[Tyrone]

7 hours ago, tim_brissy_13 said:

Finally, an A myolensis at Gardens by the Bay in Singapore. The crownshaft colour has to be seen to be believed, I couldn’t capture it in the photo:

Yes, I can see the aqua blue in that crownshaft. Will try and get a pic of mine tonight and post up. Ive got a couple which are doing it for the first time now. My plants are about 11 years from seed. I absolutely love myolensis. The leaflets have that beautiful cupping over at the ends and if they get an aqua blue crownshaft as well, I'm hooked. 

[Tyrone]

This is my most colourful myolensis. This one and another have just started doing this.

[Tyrone]

This is another but the colour is a little washed out. The next leaf base should be nice as I can see a bit of it and it’s light blue too. 

[tim_brissy_13]

@Tyronenice colour! I’ve got 6 A. myolensis and they all show similar to your second palm shown - patches of bright colour but not consistent. 
 

My largest has just dropped a leaf base and revealed fresh crown shaft this afternoon: