Florida Royal Palm and Cuban Royal Palm - How Cold Hardy?

[PalmTreeDude]

How cold Hardy are these palms? Are they zone 9b Hardy? I see them in the Tampa and Sarasota Florida area and south. I have even seen a few north of Tampa. How cold Hardy are these things? Thank you for reading!

[RedRabbit]

I understand it differs a lot depending on the palm's size. Young royals aren't very hardy at all, but one that's 30' tall can probably take 23-24f and come back from it, maybe colder even. They get to be massive so it is no surprise they're really pretty hardy. 

In Tampa I know there are pre-2010 royals at least as far north the Northdale area. There may be some in Land O' Lakes or Wesley Chapel, but I never really go up there so I'm not sure. Interestingly there is a pre-89 royal off Waters in Town n' Country, but it may just be an anomaly. 

Edited May 13, 2016 by RedRabbit

[Keith N Tampa (ex SoJax)]

There are some here in Winter Haven that survived 09-10 and 10-11.  They aren't in the best microclimates so they must have been down to 25.  In the frost holes around here it was 20 +/-, but I don't know of any Royals growing in the frost holes.  

[Walt]

I've heard posters on this forum (maybe 10-12 years ago) say they know of mature royals that survived very low 20s for short duration. There's many royals in my area that survived the horrid freezes of December 1989. Some very exposed royals have trunk damage, others have undamaged trunks.

My largest royal (R. regia) was 95% defoliated both in January of 2010 and again in December of 2010. Royals aren't very frost hardy (foliage wise).  Low 30s with frost start to damage foliage.

The below royals (in Sebring, Florida, on the southeast end of lake Jackson) survived the December 1989 freeze. Some of them have  trunk damage.

https://www.google.com/maps/@27.4787926,-81.4417704,3a,88.2y,64.13h,104.75t/data=!3m6!1e1!3m4!1s6KeJY12F39aFWsCUG8lexg!2e0!7i13312!8i6656

[PalmTreeDude]

Very interesting , thanks for replying. 

[palmsOrl]

My two large royals, as well as other royals in the Orlando area survived 2010.  I now consider them long term survivors here once large and established.

[ck_in_fla]

I'm in Winter Springs, on the Northeast side of Orlando.  My royal was planted as a seedling in 2001.  It now towers over my home at about 40 feet tall.  With the weather it has seen, I consider it a long-term survivor.  Curiously, it has never flowered.  Whenever it decides to produce seed, I intend to create as many seedlings as I can and give them away to people in this area.  I will caution them that when they are little, they do need to be protected one or two times in a normal winter.  But, once they start to trunk, it would appear that they are hardy in this area.

[palmsOrl]

Agreed, ck_in_fl.  Though there are exceptions, I consider the en-masse kill point for healthy, mature Cuban royals to be low-20s F (below 24F or so).  With all the artificial heat thrown off by manmade activities here in Orlando, I think a widespread low-20s freeze is a once or twice per century event here now.  Time will tell.

They may look rough after 1/3 of our winters, but they survive fine.  I think Roystonea regia is worth a try on the immediate coast as far north as St. Augustine, Jax Beach is pushing it, but why not give it a shot.

[Mr. Coconut Palm]

Based on what I have seen with them here in South Texas, I would say that the Cuban Royal is hardy to 25F when it established and as a little size to it.  I am one of the very few people growing a Florida Royal here, but I would suspicion that they are hardy down to 23F or 24F.  Royals do pretty well here in South Texas when adequately watered, and some even seed.  I wish they were used more in landscaping here.

Edited May 15, 2016 by Mr. Coconut Palm

[RedRabbit]

I'm beginning to wonder if R. regia is hardier than Phoenix roebelenii. The royal in the the background actually looks quite a bit better in the image below:

Edited May 15, 2016 by RedRabbit

[Ben in Norcal]

There's different kinds of hardy.  Cold hardiness and cool hardiness.  Roebelinii are pretty bullet proof here; Royals I am finding basically have no chance.

Aren't those in the pic all queens?  Or is the one behind a royal?  Hard to tell.

[RedRabbit]

7 minutes ago, Ben in Norcal said:

There's different kinds of hardy.  Cold hardiness and cool hardiness.  Roebelinii are pretty bullet proof here; Royals I am finding basically have no chance.

Aren't those in the pic all queens?  Or is the one behind a royal?  Hard to tell.

 

The one behind is a royal for sure, here it is on streetview:  https://www.google.com/maps/@28.0654572,-82.5983995,3a,75y,189.5h,85.08t/data=!3m6!1e1!3m4!1suK-O40PC1RUZHShxF7KWxA!2e0!7i13312!8i6656

Good point on cool vs cold hardiness... As far as cold goes though, I should have mentioned foliage damage is only part of the story, but I've seen a few times now where P. roebelinii seem to take more foliage damage. I'm not too sure how they compare for bud hardiness.

 

Edited May 15, 2016 by RedRabbit

[Ben in Norcal]

5 minutes ago, RedRabbit said:

 

The one behind is a royal for sure, here it is on streetview:  https://www.google.com/maps/@28.0654572,-82.5983995,3a,75y,189.5h,85.08t/data=!3m6!1e1!3m4!1suK-O40PC1RUZHShxF7KWxA!2e0!7i13312!8i6656

Good point on cool vs cold hardiness... As far as cold goes though, I should have mentioned foliage damage is only part of the story, but I've seen a few times now where P. roebelinii seem to take more foliage damage. I'm not too sure how they compare for bud hardiness.

 

Yeah, you're right - definitely a royal as apparent in that picture!

[Walt]

In my area, without exception, radiational freezes (where the air is still due to no wind) account for 95% of palm foliage damage -- not advective (windy) freeze/cold.

I moved to my present location in 1997. Since that time only once (January of 2003) have I had one day where dry, windy (advective) cold air was blowing in and had any deleterious effect on some of my palms and tropical -- and it was very minimal. My low was 29.5 degrees F that day.

All other freeze/frost events were radiational cooling in nature, allowing for lots of frost, many times hard frost. What I learned with most of these radiational cooling events was the degree of air stratification, where it was detectable of just where the 30 degree air layer line was. (30 degrees seems to be a point where foliage damage occurs.)

I have a large Ficus altissima in my front yard. This tree serves as a low temperature barometer for me during radiational freezes.

 During radiational freezes, depending on where the 30 degree air layer line is, the tree will show varying degrees of leaf damage and/or defoliation. For instance, if the temperature dropped to 26 degrees (say about 2 feet above the ground) the 30 degree line might be 10-12 feet above the ground, getting warmer with each foot of elevation. Same with pothos vines I have running 40-50 feet up slash pine trees. I've seen days where the vine leaves were totally defoliated up to about 15 feet above the ground, then going through a transition zone maybe 15 to 18 feet (where the leaves became less damaged), then no frost/freeze damage about 18 feet.

The point here is, with respect to a royal palm's foliage, is the taller it grows the less prone the foliage is to frost/freeze damage during a radiational cooling event -- as the air is warmer with each foot of elevation above the ground. A royal palm's canopy 40 feet above the ground will certainly incur less damage (if any) than a royal whose canopy is only 10 feet above the ground. Of course, this doesn't hold true for advective cooling, as the air is basically the same 10 feet up or 40 feet up due to the mixing of air.

 

[Mr. Coconut Palm]

As usual, Walt is a wealth of information with his simple, yet in depth explanations of winter cold injury.  Thanks, Walt.

[Eric in Orlando]

There were mature royal palms growing in Orlando and Winter Park prior to the '80s freezes. Most were wiped out in the Dec 1983 freeze but one growing next to a U-shaped building that faced south in downtown survived the '83 and '85 freezes but died in the 3rd one in Dec. 1989. There was an old one here at Leu Gardens but it died in '83. They are hardier than coconuts to cool and cold. But as previously mentioned are more tender as juveniles until they get some gray wood.

[Dave-Vero]

Eric's comments apply to Brevard and Indian River counties (from Cape Canaveral through Vero Beach.  The 1989 freeze destroyed many old royal palms in the protected coastal climates along the Indian and Banana Rivers, and also killed or severely damaged many native gumbo-limbo trees (Bursera simaruba).  In Vero Beach, a few old royal palms survived at least as far inland as the airport, including two visible from my house.  One of them died a few years ago, I think not for any particular reason.  In northern St. Lucie County, several miles inland, you can see old royals.  

Coconuts really are more tender.  Around 2000-2003, Vero Beach had a handful at and near the beach, and possibly a few inland.  

Vero's abundance of royals is the result of extensive planting, often of mature trees.  

[Walt]

On ‎5‎/‎15‎/‎2016‎ ‎5‎:‎01‎:‎34‎, Mr. Coconut Palm said:

As usual, Walt is a wealth of information with his simple, yet in depth explanations of winter cold injury.  Thanks, Walt.

I live right along the Lake Wales Ridge that runs down the spine of central Florida.  In my county (Highlands) those folks that live on the highest ground (relative the immediate surrounding land) enjoy about a 3/4 higher USDA hardiness zone. In both January and December of 2010 my tallest royal palm was fried (fronds killed by frost) as well as my large foxtail palm. Up in town (Lake Placid) which is about 70 feet higher in elevation the royal palms and foxtails were not hurt!

The below graphic shows a University of Florida weather tower located in Homestead, Florida, showing  the air temperature at 60 centimeters, 2 meters, and 10 meters. Note the 10 degree difference between 60 cm and 10 meters at 9:30 p.m. As you can see, the air is very stratified. Air stratification varies from night to night and hour to hour. On some nights the stratification layers are deeper and the difference from low points to higher points aren't as great. But by and large it's always warmer at night the higher the altitude (up to a point, then it starts to run colder again).

 

[Lou-StAugFL]

There are several large royals that have been on Water Street for at least the past five - six years.  You can't see them on Google Streetview, but you can see them when you walk or drive down the street. They are in the backyard.  They are surely viable for probably 10 years at a time in St. Augustine.

[Mr. Coconut Palm]

3 hours ago, Walt said:

I live right along the Lake Wales Ridge that runs down the spine of central Florida.  In my county (Highlands) those folks that live on the highest ground (relative the immediate surrounding land) enjoy about a 3/4 higher USDA hardiness zone. In both January and December of 2010 my tallest royal palm was fried (fronds killed by frost) as well as my large foxtail palm. Up in town (Lake Placid) which is about 70 feet higher in elevation the royal palms and foxtails were not hurt!

The below graphic shows a University of Florida weather tower located in Homestead, Florida, showing  the air temperature at 60 centimeters, 2 meters, and 10 meters. Note the 10 degree difference between 60 cm and 10 meters at 9:30 p.m. As you can see, the air is very stratified. Air stratification varies from night to night and hour to hour. On some nights the stratification layers are deeper and the difference from low points to higher points aren't as great. But by and large it's always warmer at night the higher the altitude (up to a point, then it starts to run colder again).

 

Wow, Walt 10F difference!  That is significant.  I would have thought the difference would be about 3 to 5F  warmer, but I had no idea, that it can be 10F warmer just a little over 36ft. above the surface.  I guess that's why mature crowns of Coconut Palms and Royal Palms that are 35ft. + in the air suffer little if any injury on chilly nights when smaller younger palms of the same species planted nearby can have moderate to severe frostbite injury.

[Walt]

20 hours ago, Mr. Coconut Palm said:

Wow, Walt 10F difference!  That is significant.  I would have thought the difference would be about 3 to 5F  warmer, but I had no idea, that it can be 10F warmer just a little over 36ft. above the surface.  I guess that's why mature crowns of Coconut Palms and Royal Palms that are 35ft. + in the air suffer little if any injury on chilly nights when smaller younger palms of the same species planted nearby can have moderate to severe frostbite injury.

That reading didn't last. Later that night the temperature spread reduced, although I can't recall by how much. Again, depending on a given radiational  cooling night, the difference in temperature varies with elevation. It's not an absolute thing, where the temperature changes in a uniform manner with every foot of elevation.

When a cold front comes through here in the winter, the first night is generally advective. On the second night the local radio meteorologist reports about a 6-7 degree difference between low and high ground locations.

[Mr. Coconut Palm]

1 hour ago, Walt said:

That reading didn't last. Later that night the temperature spread reduced, although I can't recall by how much. Again, depending on a given radiational  cooling night, the difference in temperature varies with elevation. It's not an absolute thing, where the temperature changes in a uniform manner with every foot of elevation.

When a cold front comes through here in the winter, the first night is generally advective. On the second night the local radio meteorologist reports about a 6-7 degree difference between low and high ground locations.

Hey Walt,

Same thing here, on the first night of a cold front, it's windy and cold, but the second night is the real gotcha with clear skies and calm winds.  Radiational cooling is the nemesis of tropical plant growers at their northernmost/southernmost ranges.

John

[Gregory]

I'm from SW Volusia County and am really surprised at the zone +10 plants that have popped up over the past 20-25 years or so and have survived. As other people have noted in other similar discussions, there are quite a few royals (probably 10-15 ft) right off of I-4 at the 17-92 exit. Two winters ago they got zapped, but recovered. There's also a nice 15-20ft royal just east of downtown Sanford in a residential area right on Lake Monroe (just one block away there are three mature coconut palms in someone's front yard - hard to believe but true). Picture below. In my neck of the woods across the lake there are a few coconut palms popping up in people's yards (they're selling them at Home Depot in Lake Mary and maybe other places north of Orlando too). Risky, but curious to see in a few years' time how things play out.

[Merlyn]

I've also seen a few big Royals just North and South of the Orlando Airport.  In the freezes of the last couple of years they only took medium leaflet damage, and were growing nice full new fronds by April-May.  I think the 2018 official low was 28F at the airport, and I'd say they had about 50-75% leaf tip burn on the oldest fronds.  Not 50% burn, but mostly the last few inches of each leaflet.

[FishEyeAquaculture]

Nice Royals in Odessa, FL Mobley/Gunn Hwy

[Chatta]

57 minutes ago, FishEyeAquaculture said:

Nice Royals in Odessa, FL Mobley/Gunn Hwy

Thats near my house! Those have done really well been there for quite awhile! my friend used to own the nursery that put those there.

[RedRabbit]

1 hour ago, FishEyeAquaculture said:

Nice Royals in Odessa, FL Mobley/Gunn Hwy

Thanks for sharing! Those look totally exposed, not too shabby for Odessa. Maybe it’s a little warmer up there than I thought. 

[FishEyeAquaculture]

10 hours ago, Chatta said:

Thats near my house! Those have done really well been there for quite awhile! my friend used to own the nursery that put those there.

I thought I remembered a nursery was there at one time, makes sense!

 

10 hours ago, RedRabbit said:

....Those look totally exposed, not too shabby for Odessa. Maybe it’s a little warmer up there than I thought. 

No kidding!  Like @Chatta said, there was once a nursery on that property.  But still, it's currently a vacant lot (at least nothing obvious going on), and those royals don't seem to be currently cared for....at least for the past three years, which means it is likely no one went out of their way to offer additional warmth back in Jan.  2018 (which was flippin' cold!!!)

Now I kind of want to try one (with some size, of course) here, at least in a protected area of the property.

[kinzyjr]

10 hours ago, RedRabbit said:

Thanks for sharing! Those look totally exposed, not too shabby for Odessa. Maybe it’s a little warmer up there than I thought. 

If you haven't seen @Chatta's garden, you should go see it sometime.  He has a lot of stuff that is atypical for that area.

[Chatta]

10 hours ago, RedRabbit said:

Thanks for sharing! Those look totally exposed, not too shabby for Odessa. Maybe it’s a little warmer up there than I thought. 

The lakes and forest make a good microclimate, you can see some areas are warmer than others. I think it depends a lot on elevation and protection from wind. Not far from here is a very large Teddy Bear dypsis, in a friends yard on Mobley. My gardens young, we will see how a lot of my exotics will do over time, but we have a trio of Triangle Palms that have been in ground since before 2009 and survived all colds in between. Its definitely marginal though. There's a really great jungle garden full of rare palms off South Mobley near Gunn Hwy too, Carpoxylon, large King Palms, flamethrower.... And last thing I promise hyping Keystone/Odessa, I was doing research in college and came across an article from the 20's about Keystone/Odessa noting that even back then people were growing tropicals that were out of place if you will for being this far north in the Tampa Bay area.

here's a cuban royal at another nursery down the road from it, that ones been there for awhile too not sure how long exactly

[RedRabbit]

4 hours ago, Chatta said:

The lakes and forest make a good microclimate, you can see some areas are warmer than others. I think it depends a lot on elevation and protection from wind. Not far from here is a very large Teddy Bear dypsis, in a friends yard on Mobley. My gardens young, we will see how a lot of my exotics will do over time, but we have a trio of Triangle Palms that have been in ground since before 2009 and survived all colds in between. Its definitely marginal though. There's a really great jungle garden full of rare palms off South Mobley near Gunn Hwy too, Carpoxylon, large King Palms, flamethrower.... And last thing I promise hyping Keystone/Odessa, I was doing research in college and came across an article from the 20's about Keystone/Odessa noting that even back then people were growing tropicals that were out of place if you will for being this far north in the Tampa Bay area.

here's a cuban royal at another nursery down the road from it, that ones been there for awhile too not sure how long exactly

I’ve always known your property is warm since you’re on a lake. What I’m surprised by is other parts being warm up there too. It’s too far from Tampa Bay or the Gulf to get any help from those and points north of Citrus Park probably aren’t getting much urban heating. Logically, it should be colder up there but I’ve seen a lot of examples showing otherwise. There’s something climatologically interest going on west of the Veterans...

[sonoranfans]

I think we have come to the place where a big royal is a 9b palm and a smaller one is a 10a palm.  Once that bud gets up above the ground a ways, its warmer up there and the much larger mass of the tree must cool more slowly.   

[Gregory]

On 7/17/2019 at 2:41 PM, Merlyn2220 said:

I've also seen a few big Royals just North and South of the Orlando Airport.  In the freezes of the last couple of years they only took medium leaflet damage, and were growing nice full new fronds by April-May.  I think the 2018 official low was 28F at the airport, and I'd say they had about 50-75% leaf tip burn on the oldest fronds.  Not 50% burn, but mostly the last few inches of each leaflet.

I'm really surprised seeing all these 10a-b palms/plants popping up here in central Florida. When I was a kid we had to drive to Satellite Beach where my grandparents lived to see things like this. Nowadays, you live in the right location with the right microclimate around Orlando, with some protection when needed you can grow many different things. We even have a large avocado tree in our back yard that started producing avocados about four years ago. 

[Chatta]

I was driving around West Keystone near the Pinellas border and found some more Royals at some estates on Patterson Road, these are some really large ones, probably planted as fairly big trees I bet, most of these houses aren't that old. I included a coconut for fun, also on Patterson. didnt have time to take picks so heres street view photos

 

[kinzyjr]

On 7/19/2019 at 11:59 AM, Gregory said:

I'm really surprised seeing all these 10a-b palms/plants popping up here in central Florida. When I was a kid we had to drive to Satellite Beach where my grandparents lived to see things like this. Nowadays, you live in the right location with the right microclimate around Orlando, with some protection when needed you can grow many different things. We even have a large avocado tree in our back yard that started producing avocados about four years ago. 

I'd say a few factors have played a part in the recent uptick in zone 10 plantings along the I-4 corridor and in Central Florida in general.  Obviously urbanization creating heat islands and the memory of the freezes of the 1980s fading into the past has certainly played a part.  A lot of the hardy palms in the region are being afflicted with lethal bronzing or other diseases, so that is forcing planters to consider other options that weren't on the table before.  The probability of losing a Phoenix sp. to TPPD/Lethal Bronzing on the I-4 corridor is probably greater than losing a Royal or a Foxtail to a freak freeze at this point.

The portion of your post about the avocado tree also caught my attention because I have avocados that were bearing fruit as well, but I had to "top" the trees after Hurricane Irma because they started leaning toward the house.  The worst freeze in recent memory was Jan. 2010 and the avocados and mangoes here survived that freeze. They may not have survived a repeat of 1985 or 1989. 

This brings me to another potential factor for the uptick in zone 10 plantings.  When your neighbors see you plant stuff that is normally reserved for warmer areas and it lives, they start getting a little more daring as well.  My neighbor saw me tending to my Jamaican Talls a little while back and told me he used to love going to Miami and seeing coconuts everywhere, but he didn't think they could make it here.  I have no doubt that if he was a little younger he'd have run to Lowe's and came back with a few.  When people start seeing foxtails, royals, buccaneer palms, etc. in commercial/municipal/residential plantings, they start considering those plants for their own residential plantings when they may not have before.  It will probably continue to snowball until we have another rough winter.  After the Jan. 2010 freeze, our big box stores wouldn't even carry coconuts, but now they are common place again.

[RedRabbit]

1 hour ago, Chatta said:

I was driving around West Keystone near the Pinellas border and found some more Royals at some estates on Patterson Road, these are some really large ones, probably planted as fairly big trees I bet, most of these houses aren't that old. I included a coconut for fun, also on Patterson. didnt have time to take picks so heres street view photos

Jameis Winston's place up there has a couple royals planted out too: https://www.google.com/maps/@28.1199874,-82.5795144,3a,30y,4.1h,93.24t/data=!3m6!1e1!3m4!1sKtn-9SWM--IkqWQ3KX8Stg!2e0!7i3328!8i1664?hl=en-US

 

[Jimbean]

1 hour ago, kinzyjr said:

I'd say a few factors have played a part in the recent uptick in zone 10 plantings along the I-4 corridor and in Central Florida in general.  Obviously urbanization creating heat islands and the memory of the freezes of the 1980s fading into the past has certainly played a part.  A lot of the hardy palms in the region are being afflicted with lethal bronzing or other diseases, so that is forcing planters to consider other options that weren't on the table before.  The probability of losing a Phoenix sp. to TPPD/Lethal Bronzing on the I-4 corridor is probably greater than losing a Royal or a Foxtail to a freak freeze at this point.

The portion of your post about the avocado tree also caught my attention because I have avocados that were bearing fruit as well, but I had to "top" the trees after Hurricane Irma because they started leaning toward the house.  The worst freeze in recent memory was Jan. 2010 and the avocados and mangoes here survived that freeze. They may not have survived a repeat of 1985 or 1989. 

This brings me to another potential factor for the uptick in zone 10 plantings.  When your neighbors see you plant stuff that is normally reserved for warmer areas and it lives, they start getting a little more daring as well.  My neighbor saw me tending to my Jamaican Talls a little while back and told me he used to love going to Miami and seeing coconuts everywhere, but he didn't think they could make it here.  I have no doubt that if he was a little younger he'd have run to Lowe's and came back with a few.  When people start seeing foxtails, royals, buccaneer palms, etc. in commercial/municipal/residential plantings, they start considering those plants for their own residential plantings when they may not have before.  It will probably continue to snowball until we have another rough winter.  After the Jan. 2010 freeze, our big box stores wouldn't even carry coconuts, but now they are common place again.

So when the next big freeze hits, we will have a more exact boundary of what can grow where long term.

[Chatta]

58 minutes ago, RedRabbit said:

Jameis Winston's place up there has a couple royals planted out too: https://www.google.com/maps/@28.1199874,-82.5795144,3a,30y,4.1h,93.24t/data=!3m6!1e1!3m4!1sKtn-9SWM--IkqWQ3KX8Stg!2e0!7i3328!8i1664?hl=en-US

 

Thats not far from my house, I'll go see if i can get a better photo lolol

[kinzyjr]

1 hour ago, Jimbean said:

So when the next big freeze hits, we will have a more exact boundary of what can grow where long term.

I'd say if it survived 2010 it's long term, if it survived 1985 and 1989 it's bulletproof.  Those are my benchmarks anyways.

[palmsOrl]

On 7/18/2019 at 2:30 PM, sonoranfans said:

I think we have come to the place where a big royal is a 9b palm and a smaller one is a 10a palm.  Once that bud gets up above the ground a ways, its warmer up there and the much larger mass of the tree must cool more slowly.   

I would say that regardless of size, Roystonea regia / elata should still be considered a 10a palm.  The reason they are doing so well in the Orlando area now, for instance, is (as I have said before), the data indicates that the city (and probably the inner suburbs) is now a 10a climate.  Places like New Smyrna Beach are probably bordering on 10a or high end 9b, so they live there fairly long term as well.  That said, 10a climates are still subject to low-mid 20s in really bad freezes, whereas 9b climates tend to see upper teens (which will kill any royal), so that is why I say that royals should be considered long term in 10a climates.