"A Different Kind Of Freeze" - more cold damage reports from Orlando, Fl.

The first half of the above title refers to the type of cold air mass that invaded the central Florida region last month (Jan. 24-25th to be exact). For what was the first time in ten winters of coddling palms here, my little plantation of paradise was subjected to a true advective freeze instead of radiational cooling and the accompanying frost that forms with it. For people

unfamiliar with the two terms here’s a quick description: advective cold is wind driven, usually originating from the Arctic and it arrives fast, nearly too fast for our local weather gurus to predict with any precision. It’s not uncommon to observe the temperature drop as much as 40-50 degrees overnight from the previous day’s high. The cold air pushes its way into every part of the terrain: hills, valleys, swamps, scrub plains, forests, etc. No frost forms as the wind mixes the air and

keeps it from doing so. Plant damage occurs from being subjected to below freezing temperatures. Here the extent of the damage is almost always a direct correlation on how long it stays below 32 degrees (or the plant’s individual threshold). What usually follows the advective cold is radiational cooling. The next night after the advective cold has pushed on out to sea, the air is still, and there is little to no cloud cover to trap ground heat. Thus it is radiated away into the sky. No wind also allows normal Florida humidity to settle back in. Windshields and vehicle roofs are among the first areas to be covered with frost. Plant foliage not adjacent to or under a protective canopy of some sort (e.g. live oaks) is susceptible to the frost forming on it, which without going into chemistry class 101 damages the leafs.

“Frost burn” as it is often termed is usually not fatal to palms but can damage them enough to inhibit a normal growth rate thus affecting the overall size of the crown, not to mention obliterate the palm’s aesthetic appeal. I’ve had plenty of experience with radiational freezes, as it has been a near annual event here for nine of ten years. Previously any advective cold that passed through here lowered the temp to a few degrees below freezing, not nearly enough to pose a serious threat - until now …

At 1a.m. on January 24th the temp dropped to 32F. It did not rise above 32F until a little after 10a.m. The “breaking point” for most of my palms has been right around 28F. Anything below that inflicts damage, anything over that mark usually doesn’t, in part because the freeze lasts only several hours. But the low for this morning was 25F and just as important - it stayed below 28F for about 5 hours! “Holy crap” was about the only thing I could be heard muttering to myself that

morning. I have well over 100 species of palms stuffed in here, and I left about 95% of them to fend for themselves.

Suffice to say the vast majority didn’t care for it. But like something akin to Agent Mulder on an X-Files mission I have made it my holy grail to debunk various mystiques associated with certain species and weed out the weak sisters of the palm kingdom. And so here it is – yet another one of my interminable lists, all for you …

Acoelorraphe wrightii – 3’ - none

Acrocomia aculeata – 6’– at least 50% damaged

Acrocomia 'totai' – 18’ - none

Aiphanes aculeata – 8’ – latent damage, over 75%

Allagoptera arenaria – 5’ - none

Archontophoenix alexandrae – 2’ (in pots under oak) damage confined to upper leafs

Archontophoenix cunninghamiana – 2’ (in pots under oak) some spotting, little to no browning

Archontophoenix maxima 10’ – over 50% damaged, will be fine

Areca catechu – 6’ - protected, but spotting on all fronds

Areca triandra – 5’ - protected, some spotting on all fronds

Arenga caudata – 6’ – approx. 75% damaged

Arenga engleri – 10’ - none

Arenga micrantha – 2’ - none

Arenga pinnata – 1’ - major spotting on sdlgs under oak

Attalea butyracea – 3’ - latent damage to only 2 of 4 leafs

Attalea humilis – 1’ - none

Attalea speciosa – 2’ - none

Bactris setosa – 3’ - protected, none

Beccariophoenix madagascariensis – 9’ – 100% damage to all but newest leaf

Bismarckia nobilis –18’ none; 12’ very slight to 3 NW facing leafs; 6’ defoliated

Borassus aethiopum – sdlg - none

Brahea armata – 1’ (potted) - none

Brahea brandegeei – 3’ - none

Butia capitata – 10’ - none

Caryota maxima – 2’ – maybe 25% damaged

Caryota mitis – 22’ - defoliated

Caryota obtusa – 2’ - minor spotting

Chamaedorea benziei – 3’ – damage to newest frond only

Chamaedorea cataractarum – 3’ – very slight (planted in a very protected spot)

Chamaedorea glaucifolia – 5’ – 75% damaged, planted under oak

Chamaedorea metallica – 3’ – covered but still about 25% damaged

Chamaedorea microspadix – 2’ (potted) - none

Chamaedorea plumosa – 4’ - around 50% damaged, mainly lower leafs

Chamaedorea radicalis – 3’ - none

Chamaedorea stolonifera – 3’ – none, protected spot

Chambeyronia macrocarpa – 2’ - protected, but damaged about 25%

Chamaerops humilis var. cerifera – 2’ - none

Chuniophoenix hainanensis – 1’ - none

Chuniophoenix nana – 1’ - none

Coccothrinax argentata – 6’ no damage; probable hybrid (5’) very slight

Coccothrinax barbadensis – 1’ - none, protected

Coccothrinax borhidiana – 1.5’ (15-gal. potted) - slight spotting

Coccothrinax crinita – 2’ – none

Coccothrinax inaguensis – 4’ - none

Coccothrinax miraguama var. havanensis - 2’ - none

Coccothrinax miraguama var. roseocarpa – 2’ – none, protected

Coccothrinax scoparia – 1’ - none

Coccothrinax spissa – 1’ - none

Copernicia alba – 4’ - none

Copernicia baileyana – 2’ - none

Copernicia gigas – 1’ - none

Copernicia glabrescens – 2’ (10-gal. potted) – few leaves show slight damage

Copernicia macroglossa – 1.5’ showed none, 1’ slight damage to one leaf

Copernicia prunifera – 7’ - none

Copernicia yarey – 1’ - none

Corypha utan – 12’ – completely defoliated

Cryosophila stauracantha – 2’ – none but in a very protected spot

Daemonorops angustifolia – 3’ – all stems defoliated

Dypsis ankaizinensis – 3’ - defoliated

Dypsis decaryi – 15’ – few healthy leaflets remain, at least 90-95% damaged

Dypsis decipiens – 2’ - none

Dypsis mahajanga – 2’ - at least 50% damaged

Dypsis onilahensis – 2’ – none, but in a very protected spot

Dypsis utilis – 1’ – none, protected

Euterpe edulis – 8’ – severe, about 90% damaged; some green left

Gaussia maya – 7’ – defoliated

Guihaia argyrata – 2’ - none

Howea forsteriana – 3’ - 1 of 5 fronds totally brown

Hybrid: S.romanzoffiana X B.capitata – 6’ - none

Hybrid: T.morrisii X C argentata – 2’ - none

Hyophorbe "Bottle X Spindle” hybrid" – 2’ - protected, under 50% damaged

Hyophorbe lagenicaulis – 5’ (15-gal.) – none, protected, pulled in garage

Hyophorbe verschaffeltii – 10’ – completely defoliated

Hyphaene compressa – 1’ – protected but major spotting

Hyphaene coriacea – 8’ – about 75% damaged but several healthy leaves remain

Kerriodoxa elegans – 1’ – none, but planted next to house

Licuala spinosa – 2’ – very slight spotting/streaking

Livistona australis – 6’ - none

Livistona benthamii – sdlgs. - none, protected

Livistona decipiens – 7’ - none

Livistona jenkinsiana – 1’ – very slight, maybe 10% damaged

Livistona lanuginosa – 1’ – very slight, maybe 10% damaged

Livistona mariae – 12’ - none

Livistona nitida – 2’ - none

Livistona rigida – 8’ - none

Livistona rotundifolia – 1’ - none, protected

Livistona saribus – 2’ - none

Livistona victoriae – 2’ – very slight spotting, hard to see

Phoenix canariensis – 15’ - none

Phoenix loureiri – 6’ - none

Phoenix reclinata (true form) 15’ - some streaking & browning, under 25%

Phoenix roebelenii – 6’ – none but planted next to house; specimens in open were variously damaged: 100% to nothing

Phoenix rupicola – 6’ - about 50% damaged

Phoenix sylvestris – 6’ - none

Pinanga coronata – 2’ – very slight browning despite protection

Pseudophoenix sargentii ssp. sargentii (the Fla. native)– 8’ – spotting on a few fronds, 10% damage at most

Pseudophoenix sargentii ssp. Saonae – 2’ – slight spotting

Ravenea glauca – 2’ – none (under oak)

Ravenea rivularis – 10’ – foliage over roof 100% damaged, under still green

Ravenea xerophila – 2’ – very slight streaking

Rhapidophyllum hystrix – 3’ - none

Rhapis excelsa var. Tenzan – 6’ – none (under oak)

Rhapis subtilis – 2’ - none

Roystonea oleracea – 6’ (10-gal.) – protected, placed in garage

Roystonea regia = elata – 8’ – nearly defoliated, some green on newest leaf

Sabal "California Blue" = minor var. Louisiana – 2’ - none

Sabal causiarum – 4’ - none

Sabal domingensis – 9’ - none

Sabal etonia (native to area) – 1’ - none

Sabal mauritiiformis – 10’ – some green on a few fronds only

Sabal minor var. miamiensis – 1’ - none

Sabal rosei – 1’ (potted) - none

Sabal uresana – 1’ - none

Sabal yapa – 4’ - none

Schippia concolor – 3’ - none

Serenoa repens (white form) – 3’ - none

Syagrus amara – 8’ – nearly defoliated, some green on newest two leafs

Syagrus cearensis – potted sdlg. - protected, none

Syagrus coronata - 6’ – nearly defoliated, some green leaflets remain

Syagrus romanzoffiana "Santa Catarina" – 25’, 12’, 9’ – all undamaged

Syagrus sancona – 9’ – some green on newest leaf only, near defoliation

Syagrus schizophylla – 2’ – slight streaking/spotting, planted under oak

Syagrus vagans – 1.5’ – some streaking, at least 50% damaged

Syagrus X 'costae' Hybrid – 12’ – 100% defoliated

Thrinax excelsa – 2’ – browning on only one leaf

Thrinax morrisii – 7’, 6’ – slight streaking on uppermost fronds only

Thrinax parviflora – 3’ – over 50% damaged, under oak

Thrinax radiata – 2’ – about 75% damaged

Trachycarpus fortunei – 2’ - none

Trachycarpus latisectus – 1.5’ - none

Trithrinax brasiliensis – 1’ - none

Trithrinax campestris – 1’ - none

Veitchia winin – 8’ - defoliated

Wallichia densiflora – 2’ – slight browning to upper leaves, maybe 25%

Wallichia disticha – 8’ - well under 50% damaged

Washingtonia (probable) filifera X robusta – 25’ - none

Wodyetia bifurcata – 12’ - defoliated

Zombia antillarum – 1’ – about 50% damaged

CYCADS

Bowenia serrulata - none/shaded

Ceratozamia hildae - none

Ceratozamia mexicana / robusta ? - none

Cycas angulata - one of 7 leafs burned, others fine

Cycas media var. Rockhampton - none

Cycas panzhihuaensis - none

Cycas rumphii – only several leafs browned

Cycas thouarsii – only several leafs browned

Dioon edule var. edule – none

Dioon edule var. angustifolia - none

Dioon spinulosum - minor to several leafs

Encephalartos ferox - none

Encephalartos gratus – slight overall yellowing, no browning

Lepidozamia peroffskyana - none

Macrozamia communis - none

Macrozamia diplomera - none

Zamia encephalartoides - none

Zamia fisheri = vazquezii ? – none (very surprising)

Zamia furfuracea - 50% of leaves are totally brown, 50% totally green

Zamia inermis - none, but covered

Zamia integrifolia / floridana – none, just seasonal leaf discoloration

ADDENDUM:

Enough time has passed to make some final judgments (except for latent cryptic damage), a real possibility for crownshaft palms once they begin to grow again. But that aside after reading through the list a few things jumped right out at me. One, there were quite a few palms with much less or no damage to them from this type of cold (advective) versus the radiational (frost forming) cold. For example the foliage of Sabal domingensis (but not causiarum) will fry almost completely in heavy

frost no matter the low but at 25 w/ no frost it didn’t flinch; same for most of the Phoenix roebelenii, and plenty of others with some green leafs left. Also a large Pandanus utilis (I know, not a palm) remained mostly green. And the opposite effect happened on other palms, mainly specimens that were supposedly somewhat sheltered from the cold by being placed under an evergreen canopy. Various Chamaedorea, Euterpe edulis, Howea, Wallichia densiflora to name a few showed lots of

damage, some severely. If it had been a 25F low with no driving wind pushing the cold into & through the canopy they surely would have been fine. I think that was the biggest disappointment to me in all this. Advective cold can pretty much

eliminate the microclimates you may have around your property. It seems having any sort of windbreak is the best natural protection for this type of freeze. I may have to break out a few culms of Bambusa oldhamii in the near future. Some positive items for future consideration – several “newer” species performed exceptionally well in this cold – Arenga micrantha, Dypsis decipiens, both Chuniophoenix spp., Attalea speciosa, Ravenea glauca, most every Cuban Copernicia as well as any of the “stiff-leafed” species of Coccothrinax. These all passed with flying colors as small palms, a good omen to be sure but we can’t forget that small palms close to the ground are not as exposed to cold/wind as much as larger palms. In a few years if they pass this same kind of test you’re liable to be seeing some of them in Home Depot’s, etc. Of the larger palms planted here I was very happy with the performances of Pseudophoenix sargentii, again the Champion of Crownshaft Palms (for cold tolerance anyway). Other solid results belonged to Schippia concolor, Coccothrinax argentata, Thrinax morrisii, and Cryosophila stauracantha, all denizens of the Caribbean. Other “winners” included Licuala spinosa and Livistona jenkinsiana, these with the others mentioned are all palmate palms in form. In the pinnate category other than Pseudophoenix, the only other palm that did well under the circumstances was Archontophoenix maxima, but that’s really it. Looks like if you want a well varied but cold hardy palm collection for inland central Florida, your best bet is to plant palmate.

addendum to the addendum ... (update as of 12/07)

Palms that died as a result of Jan. 2003 freeze

several Arenga pinnata sdlgs
Chamaedorea cataractarum (rotted later that winter)
1 of 2 Cham. plumosa
Chamaedorea stolonifera (just stopped growing and died that summer)
Daemonorops angustifolia (near mature climbing palm)
Euterpe edulis (had 2-3 ft of wood, was under oak canopy, tragic ...)
Gaussia maya (had 2 ft of wood)
Roystonea regia (maybe 1-2 ft of wood, in the open); marked the end of me trying these

Palms that were defoliated or severely damaged but recovered

Aiphanes aculeata (now horrida) - now setting seed up over the roof - uh oh ...
Archon. maxima - was fairly exposed but now this palm is almost completely covered by a live oak; it never produced a deformed frond(s) like alexandrae does so maybe hardier???
Arenga caudata - recovered, setting seed
Attalea butyracea, humilis, speciosa - some stunting but all recovered
Beccariophoenix (windows version) - recovered with no problems, now over roof
Bismarckia - I have one very sensitive palm, it fully recovered w/ some stunted fronds; the two much larger palms were fine thru this - genetics ...
Caryota mitis - in the open, recovered and setting seed
one Cham. plumosa and one Cham. glaucifolia recovered, are flowering
Corypha utan - recovered, now about 20 ft high, but the bud might be above ground by now
Dypsis ankaizinensis & mahajanga both recovered without a problem
Dypsis decaryi - fully recovered in 2 yrs, setting seed over the roof now
Hyophorbe verschaffeltia - fully recovered in one summer
Hyphaene coriacea - some stunted fronds but recovered fine
Phoenix rupicola & roebelenii - recovered without problems
Ravenea rivularis - very exposed but recovered OK
Sabal mauritiiformis - exhibited some latent damage but recovered OK
Syagrus amara - recovered sort of ... growth rate has never been the same
Syagrus coronata - recovered, some initial stunting
Syagrus sancona - worse than amara, palm barely grows at all
Syagrus vagans - similar to coronata, is OK now
Syagrus X costae - recovered just fine, setting seed
Thrinax radiata and parviflora - former is very exposed, both recovered OK
Veitchia winin - in the open, some stunting but has recovered fine; now has 6 ft of wood
Wallichia disticha (exposed), and densiflora (under oak canopy) - both recovered OK
Wodyetia bifurcata - exposed but recovered fine, some latent stunting

An additional post freeze technique - always apply a copper fungicide into the crown of sensitive palms, especially the crownshaft sps. whether they look damaged or not. Some can recover with this aid (Archonto., Veitchia, Wodyetia) and some will not (Euterpe, Gaussia, Roystonea). I've observed countless Archonto & Adonidia die a few months later despite opening new fronds. The bud just collapses at the bottom of the crownshaft.