2022 January 2022 Florida Freeze Report

[kinzyjr]

This topic is started to document the cold damage, or hopefully lack thereof, due to the cold spell. 

Initially, it looks like most of the damage done locally was due to frost.  As you get outside of town, the damage can get pretty severe on the "high-9b/low-10a" palms that have become more common due to the advent of Lethal Bronzing.  I'll begin with this photo I captured west of the airport on Medulla Rd.  The damage didn't even wait for the warmup to manifest.  For my own garden, I'm going to wait until it warms up to do my report.  There may be palms that look undamaged now that will show damage after the next three days go over 80F.   There may also be palms that appear to have light damage that have more extensive damage than shows at first.

@GoatLockerGuns was kind enough to compile his results from the Texas 2021 freeze in a spreadsheet that was easy to import into the Cold Hardiness Master Data.  If you'd like to do this as well, I can assist if necessary.

[TampaPalms]

North Tampa Zone 9B. 28° minimum low, 6 hours roughly below freezing.

D lutescens (Areca) 50% or more burned out in the open, under foliage I noticed 10 to 20% if that burned.

Wodyetia bifurcata (foxtail) in the open the immediate area bronzing is occurring on younger specimens, older ones there is a slight burn but not as bad so far.

So far my young white birds are burned much more than I expected, my older front yard one under a slight canopy I don't see any burn.

Variegated arboricola slight burn where there is no canopy.

I noticed many ti plants oddly not showing much damage at all.

There are a couple dozen Royal Palms within walking distance of my house in the neighborhood that appear to be burned, but not too badly. 

Robellinis are untouched.

The surprise to me is my white birds of paradise. It appears that one's planted within the last three or four years received some pretty significant burn while those that are very tall or very old so far are not showing much damage.

[D Palm]

Royal Palm - neighbor recorded 19.5F in Her yard.  Weather app said 21-22 at various times. We live in a rural wide open area w/ 2 acre plots so I tend to read the lower readings. Heating cable only - you can see green strips were cable was placed.  Pic taken a few days after freeze. Have bizzy and queens but they take a while to show damage. Pygymy date palm had some bronzing of fronds.

King Palm took serious bronzing. I threw a comforter over it and some hand warmers near the base for heat. I’ll throw up more as damage sets in.

[D. Morrowii]

Not sure if this is helpful but I had some very light damage to 2 young palms that were planted in the ground. One was a 4’ tall Buccaneer and the other a 4’ tall Veitchia Spiralis. Im not sure if the damage happened on the 36 deg night or on the 37 deg night since both palms had a frost cover on them. There was also a heating cable wrapped around it but I dont think thats what burned the leaves. I did have a fair amount of frost on the grass and the windshield on Monday the 31st. The palms that weren't covered had no damage but they are mature palms, except maybe some burn on the leaves on a pair of P elegans. Bananas leaves are spotted and a bit weathered also. 

[PalmJuan]

Hastings, St. Johns County, FL. On extreme northern border of 9b ( Tip of finger projecting northward in latest zone maps ). Measured 30 at edge of oak canopy, 25 degrees out in the open at ground level with heavy frost. Local apps varied from 25 to 30. Temperatures remained below freezing for 9 hours. Many of the plants that were considered borderline (eg. Borassus, Corypha, Copernicia, Coccothrinax , and Syagrus were covered or provided with supplemental heat (or both). Bismarckia, Brahea, Livistona, Phoenix, Sabal and Washies left totally unprotected. Most other species, including Burretokentia, Cyphophoenix, Kentiopsis, Lytocarium, Pritchardia, Thrinax and others were planted under heavy canopy or partial canopy.

 

[PalmJuan]

This was my first post to PalmTalk, and accidentally posted before completion.  Below are the rest of my comments--

 

 

A number of both pleasant and unpleasant surprises were observed. The pictures below show 3 species that were not under heavy canopy or heated in any way. Heavy damage to Dictyosperma album, little to no damage to Dypsis carlsmithii, major damage to reportedly one of the more cold hardy of the genus Corypha, Corypha lecomptei. Pleasant surprises also included little to no damage to Kentiopsis oliviformis (2 specimens...one with little overhead protection). Most Dypsis species under canopy, including those not covered, showed little if any damage. The same was true for 4 species of Burretiokentia and several species of Cyphophoenix! Ptychosperma elegans, schefferi, macarthurii and propinquum under heavy canopy showed little or no damage. Multiple specimens of Roystonea regia showed little damage under canopy but one small Roystonea oleracea received a large amount of damage (70% leaf burn). None of the Pritchardia species showed any cold damage (as of 5 days later)! These included P. remota, hardyii, pearlmani, minor, martii, beccariana, and hildebrandii. None of the covered Copernicia showed any damage. A very pleasant surprise was that an uncovered Copernicia tectorum did not show any damage at all! One uncovered Geonoma schottiana (and two covered ) showed no damage at all. Borassus aethiopium and flabellifer showed 80 to 90 % leaf damage, as did Corypha utan, umbraculifera and lecomptei. 

Many other observations were made and will appear in a more detailed report later, and in the Palmateer. My thanks go out to a hardy crew of volunteers who showed up to help cover many of the plants at the St. Johns Botanical Garden!

 

 

[Palmarum]

The only damage I have spotted so far is on a Pink Tabebuia I have growing in a pot, which is a surprise.

It is an abnormally-grown project plant growing shallow in a large pot that was outdoors, unprotected and sitting on concrete. The outermost and lowest leaves are showing damage and more damage seems to be on the way. It should recover. It is already growing new leaves.

Ryan

[Merlyn]

I'll hold off on making life/death judgements for a while, but there's a lot of brown in my yard!  Strap-leaf sized various Dypsis and an Areca Triandra are probably dead, as are several 1-3' tall Dictyosperma Album/Rubrum.  Those sailed through brief lows around 28, but couldn't take the frost and extended mid-20s on Sunday morning.  Sea grapes, bougainvillea and white bird of paradise are defoliated, but will probably grow back in a few weeks.  A lot of palms looked okay until I hit 80-85 the last couple of days.  Things like an Attalea Cohune and Arenga Pinnata are almost completely brown...with just a hint of green on some of the stems.  My Corypha Umbraculifera lost 1 leaf, but the rest of it looks really good from just putting a cardboard box over the top of it.  I think last year it was the frost at 28F that defoliated it, and the top of the box looked like snow in the mornings...

Here's my temperature profile for Sunday night 1/24/22.  It was heavy snowlike frost, but barely dipped below 30F in the backyard.  There wasn't a ton of visible damage a few days later, except for a few new cycad flushes that were mush:

In the first frost I didn't cover my variegated Caryota Mitis, but it seemed to do fine with a nearby young queen and a towering Bambusa Guangxiensis for frost protection.  I did put complete cardboard boxes over the Elaeis Guineensis whole-leaf form and Corypha Umbraculifera.  They did fine in that cold snap.  The Caryota Gigas in the front just had a piece of cardboard suspended horizontally over the top, purely for frost protection.  That worked on the above cold snap, but did not save it from severe damage on the 1/28-1/31 extended cold front.  If it survives I'll need to put an entire cover all the way to the ground, to protect from cold winds and retain more heat from the ground.  Inside the box may only be a couple of degrees warmer, but 24F vs 27F is a HUGE difference to some palms. 

Here's the weekend's profile.  Note I had installed the brown line sensor (Front Yard NW) touching a 70' tall oak's trunk, so it was effectively measuring the bark temperature and not the air temperature.  I moved it on Sunday night, and after that it tracked the green line closely (Front Yard NE).  My back yard is consistently 2-3F colder than the front yard.  For reference, the Sanford airport recorded 31F on Saturday night, and I recorded 27.5F in the front yard and 24.4-25.5F in the back yard.

[D Palm]

After a week, I’m going to agree with neighbors recording of 19F as ultimate low. The damage is by far more than I have ever seen since living at this house in 2016 and this county since ‘09. I have never seen washingtonia receive damage in this area. I have 2 neighbors with queens against a brick south facing wall that received as much damage if not more than my out on the open Queen. Bismarck’s should be fine…

[kinzyjr]

The Smashburger and I-Drive coconuts have some minor leaf yellowing and burn, but are in very good health.  You can see some Foxtails (Wodyetia bifurcata) and Christmas Palms (Adonidia merrillii) beside the I-Drive coconut.

[Brian M]

Jacksonville Beach, FL.  Ultimate low was 26.2. 8 hours below freezing averaging around 28 for most of that time. Had a light frost in the morning. This was preceded by a frost on 1/24 which also caused minor burning. These photos were taken today.

Uncovered and no damage: bismarckia nobilis, sabal palmetto, chamaerops humilis, & phoenix roebelenii.

Covered with frost blankets, no supplemental heat source: 

adonidia merrillii - Over 75% burn.

ptychosperma elegans - Over 75% burn

wodyetia bifurcata - less than 30% burn

All of my tropical plants went unprotected and got fried including hibiscus, hawaiian ti, ixora, and crotons. This has happened pervious years and I suspect will bounce back as before.

[D Palm]

@Brian M have you tried a Royal at your location. I live in between lake city and Jax. My Royal was doing OK with only a minor burn at 26…but the low of 19-20 is going to KO it.

[Brian M]

11 hours ago, D Palm said:

@Brian M have you tried a Royal at your location. I live in between lake city and Jax. My Royal was doing OK with only a minor burn at 26…but the low of 19-20 is going to KO it.

I have not. Don't think I have the room for it. I probably could've put one where my Bismarck is but I like the color more than the royals.

My neighbors, on the other hand, would have a lot of success I think. They have a lot of space with a nice oak canopy.

[kinzyjr]

At this point, the coconuts in the area have held steady as far as their cold damage, so I'll use those as my first report.  None of them were covered or protected.  There are a few more I'll capture for assessment purposes, including one with about 8' of trunk on the other side of the hill.

These are mine:

Maypan: ~30% leaf damage - The lowest fronds on the right and left were already brown and half brown respectively, so damage is estimated using the other fronds.  Roughly what I've come to expect from this cultivar.

Atlantic Tall: ~60% leaf damage - One of the fronds was already dead and brown, but left it on in case I wrapped the palm for protection.  I can verify frost settled on some of the fronds on 01/31/2022.  Might have to get one from @redant to compare the strength of his stock to my conditions vs. the usual.  There is a juvenile 10 feet from this one that got some overhead shelter from a sea grape branch that seemed to handle things better.  This one was disappointing, but not totally unexpected.

Panama Tall: (newly planted but under light mango canopy) ~15% leaf damage  Pretty impressive for a palm that had been in the ground less than a month.

Suspect these next three are Green Malayan:

Glendale Coconuts: ~40% leaf damage

Main St. Coconuts: ~30%

Reynolds Road: (juvenile and outside the heat island) ~70% leaf damage

Weather at Lakeland Linder (KLAL):

In my yard, my main sensor read 34F for an ultimate low in January, with that reading coming from near the Maypan.  I had sensors throughout the yard, with the lowest reading 31F about 4 feet from the Atlantic Tall.  The 29th was no picnic either, with winds in excess of 20MPH much of the day.  On 1/24, the airport recorded 31F for a low, but my reading was way higher at 36F+.   Overall, it was either near or under freezing from 11pm through 8am on 1/31.

January 31st was likely the one that caused the damage you see as there was heavy frost everywhere that wasn't under canopy.  Since most of the coconuts are not planted under any canopy at all, they took damage.  I've considered adding some canopy to these areas, but in some cases, it would be difficult to do so without compromising light levels too much.

[kinzyjr]

The Carpoxylon macrospermum in town took no damage.  The specimens below are at Common Ground and Lake Hollingsworth.  There are more at Barnett Park and City Hall.  I have a young one on my property that also took no damage.

Carpentaria acuminata.  They not only took no damage, they put out a new leaf during the ordeal.  These are on my lot.

Veitchia arecina - These are hit or miss.  The cold didn't bother them as much as frost did.  The first photo shows a smaller one with nothing overhead.  About 70% of the leaf is damaged.  The second shows one with edge canopy protection for almost all of the fronds, with the exception being the frond on the lower left level.  There is minor spotting in some places, but overall, little actual damage other than that one leaf without canopy.  The lesson learned is to get canopy in place for the one that was damaged.

Veitchia subdistichia - Very little frond damage considering their reputation.

[kinzyjr]

All of these are in my garden.

Both Beccariophoenix alfredii and Beccariophoenix fenestralis were not bothered.

Dypsis cabadae received some leaf tip burn.  The rest of the Dypsis had no change in their condition from pre-cold to post cold.

Dypsis prestoniana (next two photos)

Dypsis pembana

Dypsis lanceolata

This one is from Common Ground - minor leaf tip damage on Areca catechu 'Dwarf'

[kinzyjr]

A few more to round out today's observations:

Dypsis leptocheilos - flowering and undamaged

Chambeyronia macrocarpa - overtrimmed, but healthy and undamaged

Zombia antillarum - undamaged

Archontophoenix purpurea - undamaged

[Looking Glass]

2 hours ago, kinzyjr said:

Dypsis pembana

Dypsis lanceolata

Your Dypsis Pembana looks more like my Allagoptera Arenaria than my Pembana.  Still can’t get over how good your B Fenestralis looks.  Glad you made out pretty well.  

Edited February 11, 2022 by Looking Glass

[D Palm]

@Brian M A Royal in my observation is definitely more hardy than the foxtail and other palms your currently growing. I have a few potted ones that need a home if your interested. Gathered seeds from a “wild” Royal growing in S. Florida. My foxtail growing in a no heat greenhouse looks way worse than my Royal after this event. 

Edited February 11, 2022 by D Palm

[kinzyjr]

Some additional observations from the yard:

Archontophoenix alexandrae and Archontophoenix cunninghamiana with no damage

Pseudophoenix sargentii - no damage

Hyophorbe lagenicaulis - leaf tip damage

Satakentia liukiuensis ~10% leaf spotting on oldest frond

Howea forsteriana - this species actually likes when we get perpetual cool

Chambeyronia macrocarpa, Chambeyronia oliviformis (formerly Kentiopsis), Chambeyronia macrocarpa 'Houilou' in the next three.  The first photo has brown leaf tips, but those were actually like that for a bit before it got cold in January. 

Cryosophila warscewiczii - one of the better 9b palms in my opinion since it grows so well in part shade

Adonidia merrillii babies showing some cool spotting and one having minor leaf damage.

A Rhizophora americana (red mangrove) growing with no canopy and in a pot.  No damage.

Roystonea regia - if there is damage, it is minor way out at the leaf tips.  Pretty good for a juvenile.  There is one in the back that got some damage on one of the fronds laying flat.

A volunteer Wodyetia bifurcata.  Minor leaf spotting if anything.  I threw my overstock seeds in the bone pile and the squirrels ate most of them.  They must have buried and forgot this one.

[redant]

On 2/10/2022 at 11:39 PM, kinzyjr said:

At this point, the coconuts in the area have held steady as far as their cold damage, so I'll use those as my first report.  None of them were covered or protected.  There are a few more I'll capture for assessment purposes, including one with about 8' of trunk on the other side of the hill.

These are mine:

Maypan: ~30% leaf damage - The lowest fronds on the right and left were already brown and half brown respectively, so damage is estimated using the other fronds.  Roughly what I've come to expect from this cultivar.

Atlantic Tall: ~60% leaf damage - One of the fronds was already dead and brown, but left it on in case I wrapped the palm for protection.  I can verify frost settled on some of the fronds on 01/31/2022.  Might have to get one from @redant to compare the strength of his stock to my conditions vs. the usual.  There is a juvenile 10 feet from this one that got some overhead shelter from a sea grape branch that seemed to handle things better.  This one was disappointing, but not totally unexpected.

Panama Tall: (newly planted but under light mango canopy) ~15% leaf damage  Pretty impressive for a palm that had been in the ground less than a month.

Suspect these next three are Green Malayan:

Glendale Coconuts: ~40% leaf damage

Main St. Coconuts: ~30%

Reynolds Road: (juvenile and outside the heat island) ~70% leaf damage

Weather at Lakeland Linder (KLAL):

In my yard, my main sensor read 34F for an ultimate low in January, with that reading coming from near the Maypan.  I had sensors throughout the yard, with the lowest reading 31F about 4 feet from the Atlantic Tall.  The 29th was no picnic either, with winds in excess of 20MPH much of the day.  On 1/24, the airport recorded 31F for a low, but my reading was way higher at 36F+.   Overall, it was either near or under freezing from 11pm through 8am on 1/31.

January 31st was likely the one that caused the damage you see as there was heavy frost everywhere that wasn't under canopy.  Since most of the coconuts are not planted under any canopy at all, they took damage.  I've considered adding some canopy to these areas, but in some cases, it would be difficult to do so without compromising light levels too much.

More then welcome to some of my talls.

[Brian M]

On 2/11/2022 at 10:08 AM, D Palm said:

@Brian M A Royal in my observation is definitely more hardy than the foxtail and other palms your currently growing. I have a few potted ones that need a home if your interested. Gathered seeds from a “wild” Royal growing in S. Florida. My foxtail growing in a no heat greenhouse looks way worse than my Royal after this event. 

I'll probably pass. Thanks though! If it truly grew well, it would be way too big.

We're taking a long weekend this spring down to Orlando and then to Tampa. I'm going to try to find some nurseries along the way to try and find a leucothrinax morrisii. That'll be my last zone push attempt.

[kinzyjr]

Some additional photos of interest from around town.  Those familiar with the Remarkable Palms of Tampa Bay and Lake Wire threads will recognize many of these. :

Syagrus coronata - no damage

Caryota mitis and Dypsis lutescens - minor damage in an exposed location prone to a lot of high winds

Dypsis decaryi - no damage

Dictyosperma album 'conjugatum' - no damage.  I have seen a few with minor frost damage in other areas.

Archontophoenix cunninghamiana - minor damage from wind dessication or no damage against a building

Saribus rotundifolia - ~50%-60% damage in an open and windy location

Beccariophoenix alfredii - leaf tips dessicated from wind.  Most outside of this particular location have no damage.

Hyphaene coriacea - no damage

Caryota obtusa - light damage at this location, none at other locations

Ptychosperma elegans and Satakentia liukiuensis - no damage with good siting

Dypsis leptocheilos - no damage

Areca catechu 'Dwarf' - minor damage

Licuala grandis - no damage

Carpoxylon macrospermum - no damage

Roystonea regia - no damage on one of the large, flowering specimens around town

Cocos nucifera - these are in the highlands.  The second photo isn't the best, but these were undamaged and, at ~240ft in elevation, might be the highest trunking coconuts in Florida.

Arenga pinnata - didn't notice any damage

Hyophorbe lagenicaulis - most of them around town took minor damage.  The larger one in the photo has been around for a long time.

 

Just remember, not far from us, it is a challenge to grow things we consider lay-ups.  If you take Knights Station Rd to Tampa from central Lakeland, you get a glimpse of what could have been.  As I was headed down the road, I was stunned after I got past Galloway Rd at the common 9b palms with damage.  After I passed FL-39/Alexander St./Paul Buchman Hwy, it was even more pronounced  This verifies that the numbers posted outside of the small heat island here were accurate.  A Phoenix roebelenii doesn't typically burn 100% until the low 20s.  I counted no less than 3 dead coconuts on the way.  Dypsis lutescens, Hawaiian Ti, and other plants that have little or no damage here were 100% freeze burned.  The map below shows a few routes you can take to verify the damage:

Toasted Pygmy Date Palms and Bismarckia with ~50% damage.

Here are weather records from Zephyrhills Municipal (KZPH) and Plant City Municipal (KPCM).  Look at the difference a short distance can make 24F vs. 32F.  I think the area in question was much closer to the 24F mark:

[RedRabbit]

Thanks @kinzyjr, Lakeland did well! I’m a little surprised by the Dictyosperma album, that palm might be underrated for cold tolerance.

[cocoforcoconuts]

Does anyone have any current post freeze pictures of coconut palms around Tampa Bay? Particularly the non-marginal coconut growing areas near the water like St. Pete, south Tampa, Apollo Beach, Palmetto, etc.

Edited February 14, 2022 by cocoforcoconuts

[Merlyn]

On 2/12/2022 at 11:29 PM, kinzyjr said:

A Phoenix roebelenii doesn't typically burn 100% until the low 20s.  I counted no less than 3 dead coconuts on the way.  Dypsis lutescens, Hawaiian Ti, and other plants that have little or no damage here were 100% freeze burned. 

There's definitely some cold tolerance variability in Roebellini.  I have three tall ones (5-7' of clear trunk) and had basically no damage at 24.4F with frost.  My neighbors have several in an odd "island" in the middle of their split driveway, and only had a small amount of burn on the top fronds...probably from frost.  But just down the road into Lake Mary there's a triple next to a house that is utterly destroyed, with not a hint of green on it.  That area was several degrees warmer than my house.  So the only thing I can think of is that the house is in the middle of the lowest spot for several hundred yards in every direction.  My guess is that spot is just a cold sink.  I'll try to get a photo later today.

In the same area I photographed a couple of Royals and posted them in the remarkable palms of Orlando thread.  They are pretty badly burned, but probably will survive.

[RedRabbit]

I found a small palm garden in Carrollwood Village Park today. I recorded 30f and it was probably about the same here, but these palms were completely out in the open so they probably saw 27-28f and frost.

Caryota mitis, Coccothrinax crinita, Dypsis decaryi, and foxtails all had minor to moderate burn. They also had something labeled Arenga engleri with moderate damage, but I’m skeptical since it should be able to handle that.

 

Hyophorbe lagenicaulis had severe damage. There was also some mystery crownshaft palms that all took severe damage

And I was very surprised to see a couple Polyalthia longifolia with minimal damage. This is supposed to be a 10a tree, but apparently it’s actually pretty hardy.

Edited February 21, 2022 by RedRabbit

[kinzyjr]

1 hour ago, RedRabbit said:

And I was very surprised to see a couple Polyalthia longifolia with minimal damage. This is supposed to be a 10a tree, but apparently it’s actually pretty hardy.

I think these will prove adaptable to the warmer parts of 9b.  The ones here are all sited very well and saw no damage.

On 2/19/2022 at 7:58 AM, Merlyn said:

There's definitely some cold tolerance variability in Roebellini.  I have three tall ones (5-7' of clear trunk) and had basically no damage at 24.4F with frost.  My neighbors have several in an odd "island" in the middle of their split driveway, and only had a small amount of burn on the top fronds...probably from frost.  But just down the road into Lake Mary there's a triple next to a house that is utterly destroyed, with not a hint of green on it.  That area was several degrees warmer than my house.  So the only thing I can think of is that the house is in the middle of the lowest spot for several hundred yards in every direction.  My guess is that spot is just a cold sink. 

I agree.  I've seen them get damaged at 30F with frost, and I've seen a few take 24F in some isolated cold pockets with minor damage to the point where it was unnoticeable unless you were standing right next to it.  There are even a few that have recovered from temperatures in the high teens.  It's also possible that some of the reports we've had in the past are actually roebelenii-dominant hybrids. That would probably also nudge hardiness in that direction.

--

Those who have seen the Veitchia arecina I shared in the Remarkable Palms of Tampa Bay thread will take special interest in this one.  No damage.

@D. Morrowii did an experiment where he used an Adonidia merrillii seedling in a pot completely exposed just to see what would happen.  I didn't realize I had done the same experiment until I started moving some things around today.  His has less damage as he recorded a higher low temperature and a shorter duration.  We both had frost unfortunately.

[RedRabbit]

4 minutes ago, kinzyjr said:

I think these will prove adaptable to the warmer parts of 9b.  The ones here are all sited very well and saw no damage.

Those who have seen the Veitchia arecina I shared in the Remarkable Palms of Tampa Bay thread will take special interest in this one.  No damage.

@D. Morrowii

Judging by what I saw mast trees might do okay in colder parts of 9b even provided they’re not planted in the middle of a field like these were.

It’s great to see the veitchia took no damage! That’s a testament to how good of microclimate some of the lakes there provide. 

[Merlyn]

Here's photos of the two Royals in Lake Mary, they are about 90% defoliated but the one on the left has a new green spear opening.  The one on the right has a spear that will probably open in a week or two.  My best guess is these saw upper 20s, maybe 28-30F with frost:

The reason I say this is that the next-door neighbor's Foxtails were mostly but not completely burned.  The left one is burnt, the middle one is about 75% burnt, and the right one (partially hidden from view by the tree) is about 50% burnt.  They have two others also around 50% burned.  My Foxtails of a similar size were completely torched at 27.5F, so I'm guessing these may have seen 30F or just a bit below:

[D Palm]

Update: First is my high plateau coconuts…dead. A pineapple Guava untouched, along with my Sylvester showing slight burning on the tips. Royal all trimmed up, totally defoliated but not dead. King palm and orange BoP shared a blanket with hand warmers. A sabal causiarum I planted last Nov with some burning,  but now actively growing

[kinzyjr]

13 hours ago, Merlyn said:

The reason I say this is that the next-door neighbor's Foxtails were mostly but not completely burned.  The left one is burnt, the middle one is about 75% burnt, and the right one (partially hidden from view by the tree) is about 50% burnt.  They have two others also around 50% burned.  My Foxtails of a similar size were completely torched at 27.5F, so I'm guessing these may have seen 30F or just a bit below:

Foxtails exhibit quite a wide range of cold tolerance.  Just down the road, there is one that is bronzed completely 200 yards from a triple with none of the three having a scratch.  They're sited in a wide open parking lot with no other discernible difference other than genetics.  Traveling from Lake Hamilton to Winter Haven, there is a yard full of Foxtails on the south side of the lake.  Most of them came through with no damage from the winter last year, but one was 100% bronzed and eventually perished.

[Merlyn]

8 hours ago, D Palm said:

Update: First is my high plateau coconuts…dead. A pineapple Guava untouched, along with my Sylvester showing slight burning on the tips. Royal all trimmed up, totally defoliated but not dead. King palm and orange BoP shared a blanket with hand warmers. A sabal causiarum I planted last Nov with some burning,  but now actively growing

 

Unfortunately I guess we know the approximate bottom end on B. Alfredii seedlings...    Mine (same size) took a tiny bit of damage at about 27-28F, but 19F is really cold!  Did they hang on for a bit, or were they immediately burnt to a crisp?

[D Palm]

@Merlyn They were totally dead the next day.  A few weeks later I pulled the spears, hollow inside.  Sylvester took a long time to show damage.  Damage was about 60% burn on Royal but kept creeping in, spear has not pulled. I think the officially recorded temps was 21-22 for the night, but my neighbor recorded 19 with her set-up.  My foxtail in non-heated green house totally defoliated, but should come back.  I had royal seedling sprouts in the same green house, 3 dead, rest have some damage, 1 totally unscathed surprisingly...scratching my head but its a keeper.

Ice cream banana's are growing back form the same psuedo trunk...so no killing to ground!! def more hardy than a standard dwarf cavendish. 

My Livistonia Chinensis (5 total cluster plantings) took about 40-50% burn....less burn than my Washingtonia.

Sabal uresana unscatched...AND final putting out it's first non-strap leaf!!!

[D Palm]

@Merlyn On another note, the Royals in the photos look horrible for an upper 20 blast.  I never protected mine at those temps w/ frost and it did not show anywhere near as much damage.  23 fried a good bit of it last year, maybe as bad as the pics.

[D Palm]

Update: removed royal palm, totally dead. High plateau coconuts dead. All of my royal seedlings except 1 died in the unheated greenhouse. Foxtail growing in unheard greenhouse is dead. Everything else is growing nicely. Archontophoenix cunninghamiana is actually growing. 

[kinzyjr]

11 hours ago, D Palm said:

Update: removed royal palm, totally dead. High plateau coconuts dead. All of my royal seedlings except 1 died in the unheated greenhouse. Foxtail growing in unheard greenhouse is dead. Everything else is growing nicely. Archontophoenix cunninghamiana is actually growing. 

Not all great news, but sounds promising the the Archontophoenix cunninghamiana is doing alright.  Thanks for the update!

[kinzyjr]

An odd addition to the freeze damage from January - a homeowner in North Lakeland reported losing a Foxtail palm (Wodyetia bifurcata) and a Christmas palm (Adonidia merrillii).  They said their coconut defoliated but is coming back.

[Brian M]

Interesting observation that Ive been meaning to post for a few months, I found a monstera deliciosa growing in between a bunch of stuff between my house and my neighbors. It only had one dead leaf from the freeze, everything else was green as can be. Im sure the canopy it's under and being in between 2 houses helped a bunch, but was still surprised temps in the high 20's didn't kill it.

[kinzyjr]

A follow-up to the original post that illustrates the difference a UHI can make. 

Here are the Wodyetia bifurcata from the original photo today.  They each have one good frond out and will probably make it if we have a gentle winter:

Here are a few at Lake Miriam Publix.  They are healthy and undamaged:

The straight line distance between these two locations is approximately 5.5 miles.