Comprehensive Hardiness List

[Mauna Kea Cloudforest]

This new forum split is confusing, but since this is about hardiness, i will post it here even though this doesn't qualify as "hardy" by the measure that palms grow natively here.

Has anyone seen this list of hardiness results? It has quite a number of surprises, some rather tropical palms turn out to be pretty hardy. Now hardy for me means it can take some dips into the upper 20's, i.e. -2C at most in the open before I see any damage. This list was compiled by a nursery in Cornwall, UK, and while it's mild down there, i expect most of those specimens were small.

http://www.trebrown.com/documents/climate/palmhardinesstrials.php

Some of this information is highly relevant to us growers in California where we occasionally see -2C/28F. I think this list is very honest and accurate, as they have king palms rated to receive frost damage at 0C for kings exposed to the night sky, which I have also experienced. 31-32F for 8 hours will damage a king out in the open. But it looks like there are a ton of more tropical looking palms which are way more hardy than king palms:

ttalea cohune 9a -2°C -4.8°C ? Attalea speciosa 9a -2°C -4°C Beccariophoenix madagascariensis 9b -1°C -3°C Bismarckia nobilis 9b -1°C -4.5°C ?

Corypha lecomtei 9a -3°C -6.7°C ? Going by its providence it should be hardier than C. umbraculifera. Corypha umbraculifera 9a -3°C -6.7°C ? We've also tried C. utan with mixed results. It is certainly not as hardy as this one. Dypsis ambositrae 9a ? -5°C ? The palm is too new to know for sure. It may be much hardier than this. Dypsis baronii 9a -3°C -5°C ? May be much hardier than this. Dypsis crinita 9a -1.5°C -3.5°C Not as hardy as some say. Dypsis decipiens 9a -2.5°C -6°C ? Dypsis heteromorpha 9a ? -8°C ? This is certainly the hardiest of the Dypsis, but there are 10 or 11 other Dypsis, which grow at a similar altitude that we would like to try. Dypsis oropedionis 9a -2.5°C -5°C ?

There are even more, but this is very interesting and useful. There are so many palms that have so much potential and should be grown a lot more.

[sarasota alex]

I think these lists are great when applied to the right climate. In a wrong climate they could be misleading. A great example is the Needle Palm (Rhapidophyllum hystrix), which has very specific summer requirements to be the cold-hardy champion and in some climates barely survives -2C at best.

I like how the Palmpedia is doing it with the Survivability Index. It's split into a Mediterranean and Subtropical is very useful. http://www.palmpedia.net/wiki/Palmpedia:PALMPEDIA_SURVIVABLILITY_INDEX

A link that I like and have used in the past for our Florida conditions (compiled by L. Noblick) is this http://www.bg-map.com/PLMTBLA.HTML

Also I highly recommend the Freeze Damage Data section of this forum - http://www.palmtalk.org/forum/index.php?/forum/13-freeze-damage-data/

[gyuseppe]

this list is very confusing,for personal experience actual results are different

(the owner of the nursery ,mister Phil Markey ,is a friend of mine)

[Phoenikakias]

Cold hardiness is one aspect, cool hardiness is another apsect. A cold hardy palm is not necessarily also cool hardy (to endure a prolongred cool period) and to make another discrimination cooll hardiness has to be divided to wet cool hardiness (for mediteranean climates) and dry cool hardiness (for subtropical climates). It appears also to be mostly an interaction between cool and cold hardiness. One palm that is not particularly cool (wet or dry ) hardy, usually sucumbs to significantly higher cold temps, if it has previously to endure not favouring cool temps.

[Grasswing]

this list is very confusing,for personal experience actual results are different

(the owner of the nursery ,mister Phil Markey ,is a friend of mine)

Agreed, many growers in Czech Republic has experience that Trachycarpus sp. survive -15°C without any damage.

[sonoranfans]

I'll second Alex, the freeze damage section of this forum can provide great information as posters have detailed temps and you know where they live. Anyone who experiences cold effects can help all of us by contributing their experiences there

[Mauna Kea Cloudforest]

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

[Kailua_Krish]

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

"I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum."

This would rule out vast areas of the South East US that have little chance of growing the tropical palms that are most discussed in the main forum. I would propose that people post wherever they feel its most relevant.

-Krishna

[Mauna Kea Cloudforest]

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

"I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum."

This would rule out vast areas of the South East US that have little chance of growing the tropical palms that are most discussed in the main forum. I would propose that people post wherever they feel its most relevant.

-Krishna

You are probably right, I will post in both places for a while until I see where I get the most relevant answers. I suspect for most topics it will be in the main forum where the guys hangout that grow all the newcomers that are of interest in the king palm zones of California. But I have a major interest in hardy palms because I want the backbone of my garden to be bullet proof. So I am very much interested in data coming from zones colder than my own. I have a big investment in sabals, braheas, parajubaea and phoenix species that are pretty much bullet proof here, and I am always interested in finding more that can grow here completely worry free. When i mean worry free, i mean I can take off to Hawaii in December and January and not worry I will come back to palms that look like someone took a blow torch to them.

[Phoenikakias]

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

"I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum."

This would rule out vast areas of the South East US that have little chance of growing the tropical palms that are most discussed in the main forum. I would propose that people post wherever they feel its most relevant.

-Krishna

You are probably right, I will post in both places for a while until I see where I get the most relevant answers. I suspect for most topics it will be in the main forum where the guys hangout that grow all the newcomers that are of interest in the king palm zones of California. But I have a major interest in hardy palms because I want the backbone of my garden to be bullet proof. So I am very much interested in data coming from zones colder than my own. I have a big investment in sabals, braheas, parajubaea and phoenix species that are pretty much bullet proof here, and I am always interested in finding more that can grow here completely worry free. When i mean worry free, i mean I can take off to Hawaii in December and January and not worry I will come back to palms that look like someone took a blow torch to them.

That was very wise speaking. If I could add something, it would be that the established, adult bullet proof palms can provide the necassary canopy for later marginal palms without sky rocketing the water bill. Conifers, Acers and other wide leaf trees present a major competition for nutrients and water for our tender palms, and unless one is rich, or has a water well, or plenty of underground water (highly improbable on slopy regions in a warm mediterranean climate) he would have to spend a lot of money to preserve such a canopy.

[PALM MOD]

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

"I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum."

This would rule out vast areas of the South East US that have little chance of growing the tropical palms that are most discussed in the main forum. I would propose that people post wherever they feel its most relevant.

-Krishna

You are probably right, I will post in both places for a while until I see where I get the most relevant answers.

The solution is to post it in the Main Forum and tag it as "Cold Hardy" - just as this topic should have been. That way it gets the exposure of the Main Forum (if that is what you want), but will appear on the Cold Hardy tag list of all topics that could potentially be of interest to cold hardy growers.

[sonoranfans]

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

"I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum."

This would rule out vast areas of the South East US that have little chance of growing the tropical palms that are most discussed in the main forum. I would propose that people post wherever they feel its most relevant.

-Krishna

I am with Krishna. Funny how a 9b gardener sees little difference between 9b and 9a while the 9a gardener sees a world of difference between his climate and 9b.

[_Keith]

Cold hardiness has many factors other than just temperature, which is what makes it so hard. A few years back, I scoured the aforementioned site and every other site I could find on the internet and made a master list. I'll see if I can find it and link it, but any cold hardy list is just a suggestion. If you don't see it growing around, then plant preparing to lose is my motto.

[Mauna Kea Cloudforest]

I have a lot of live Oak that don't compete with the palms for water. But you are right, a sabal with giant fronds is so much more spectacular!

You guys are all making great and very valid points. I also find the hardiness rating section of the PalmTalk forum to be one of the best resources. However, you guys missed the point I was trying to make. I wasn't arguing that this is a good hardiness list. I was simply pointing out for the sakes of us folks in California that many of the new Caledonia and Madagascar palms turn out to be a lot hardier than previously thought. If they do that well in Cornwall where there is little Summer heat and plenty of long Winter damp cold and chill, they are going to so even better in California.

Of coure, many of you read the list and looked at all the usual super hardy specimens that didn't get that high of a rating. I suppose that 9b hardiness questions and discussions for which the New Caledonia and Madagascar species hardiness is relevant don't really belong in the main forum. This sub-forum should probably focus only on those areas where palms normally don't grow or aren't grown widely, so really zones 8b and below.

I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum.

"I would propose a delineator: if you can grow a canary date palm into adulthood in perpetuity without any protection whatsoever, then perhaps the topic is best suited to the main forum."

This would rule out vast areas of the South East US that have little chance of growing the tropical palms that are most discussed in the main forum. I would propose that people post wherever they feel its most relevant.

-Krishna

You are probably right, I will post in both places for a while until I see where I get the most relevant answers. I suspect for most topics it will be in the main forum where the guys hangout that grow all the newcomers that are of interest in the king palm zones of California. But I have a major interest in hardy palms because I want the backbone of my garden to be bullet proof. So I am very much interested in data coming from zones colder than my own. I have a big investment in sabals, braheas, parajubaea and phoenix species that are pretty much bullet proof here, and I am always interested in finding more that can grow here completely worry free. When i mean worry free, i mean I can take off to Hawaii in December and January and not worry I will come back to palms that look like someone took a blow torch to them.

That was very wise speaking. If I could add something, it would be that the established, adult bullet proof palms can provide the necassary canopy for later marginal palms without sky rocketing the water bill. Conifers, Acers and other wide leaf trees present a major competition for nutrients and water for our tender palms, and unless one is rich, or has a water well, or plenty of underground water (highly improbable on slopy regions in a warm mediterranean climate) he would have to spend a lot of money to preserve such a canopy.

[Phoenikakias]

... or you have not yet realized the extent of the competition. Has it ever occured to you how some palms having been previously stagnant for several years start off in a spectacular way after non palmy competition has been removed? It has occured to me several times with citrus trees vs Arenga pinnata, prunus trees vs Wallichia spss, Sabal spss vs olive trees. Before removal palms had been looking healthy but very slow growing and one could be misled from this fact to the conclusion that the specific climate/microclimate was not favourable for faster growth.

[Mauna Kea Cloudforest]

The only palm so far that won't grow near my oaks is the Queen palm. But it seems more soil related. All the palms I grow do great under the live Oak.

Citrus and olives would not be my first choice for overhead canopy, toots are way too dense and competitive.

[_Keith]

Here is the list I did many years ago, compiled from many websites at that time.

http://www.palmtalk.org/forum/index.php?/topic/9435-palm-freeze-survival-list/

Posted 09 January 2008 - 08:06 PM

OK, here is another rendition. I think this is the end of commonly available info on minimal survival temps.

Disclaimers

I am not a palm expert. This info is not scientific. It was gathered from various websites, blogs, message boards including this one, etc.

In each case I have attempted to verify minimal survival temps from at least 2 sources, 3 where possible, in a very small number it was only 1.

This list represents temperatures where palms were known to survive, not die. Many of these palms have died at higher temperatures. I would say that a healthy palm, in the right place might survive these minimum temps.

No guarantees. This is an experimenters reference.

In the next renditions, I will add common names, and frost tolerance info, where available.

I started this as a learning effort for myself. I could use some help. I know some folks on this board have more info. Quite a bit of this was picked up from the past post of active posters here.

My interest here is creating best list possible. After scouring a great number of these lists, I think in the end, with your help, this could be the most comprehensive as far as total number of palms covered, if nothing else. It is completely in the public domain for all to use as they see fit.

NFT = Not frost tolerant, regardless of surface temp. Just starting to add this info. It is not at all complete.


Acanthophoenix rubra 20
Acoelorrhaphe wrightii 20
Acrocomia aculeata v mexicana 26
Acrocomia media 25
Acrocomia totai 26
Adonia Merilli 25
Allagoptera arenaria 25
Allagopteria campestris 25
Allagopteria leucocalyx
Archontophoenix alexandrae 28
Archontophoenix cunninghamiana 28
Arenga caudata 27
Arenga engleri - shorter form 20
Arenga engleri - taller form 23
Arenga micrantha 20
Attalea cohune 28 N
Attalea dubia 25
Attalea rostrata 27
Bactris mexicana 27
Bactris setosa 25
Beccariophoenix alfredii 28
Beccariophoenix madagascariensis 26
Bismarckia noblis 24
Borassus aethiopum 24
Brahea aculeata 24
Brahea armata 15
Brahea berlandieri 15
Brahea brandegeei 24
Brahea clara 24
Brahea decumbens 15
Brahea dulcis 15
Brahea dulcis 'Blue' 26
Brahea edulis 24
Brahea moorei 15
Brahea nitida 26
Brahea pimo 25
Brahea sarukhanii 25
Brahea 'Super Silver'
Burretiokentia hapala 28
Butia archeri 25
Butia arenicola
Butia bonetti 10
Butia capitata 15
Butia capitata 'lax leaf' 16
Butia capitata 'odorata' 15
Butia capitata x Jubea 16
Butia capitata x Syagrus coronata 'Butiagrus houstonii' 16
Butia capitata x Syagrus picophylla 'Butia x picophylla' 16
Butia capitata x Syagrus romanzoffiania 'Mule Palm' 16
Butia eriospatha 15
Butia microspadix
Butia odorata
Butia paraguayensis 15
Butia purpurascens 15
Butia yatay 15
Calamus caryotoides 26
Calamus usitatus 26
Caryota gigas 27
Caryota gigas 'Black Trunk' 27
Caryota maxima 'Himalaya' 27
Caryota mitis 25
Caryota 'Mystery Cluster'
Caryota obtusa (India Form) 27
Caryota ochlandra 27
Caryota urens 29
Ceroxylon alpinum 26
Ceroxylon parvifrons 23
Ceroxylon quindiuense 26
Ceroxylon vogelianum 28
Chamaedora pumila 26
Chamaedorea brachypoda 26
Chamaedorea cataractarum 26
Chamaedorea costaricana 25
Chamaedorea elegans 26
Chamaedorea ernesti-augusti 27
Chamaedorea fragrans 27
Chamaedorea glaucifolia 26
Chamaedorea graminifolia 30
Chamaedorea hooperiana 27
Chamaedorea klotzchiana 26
Chamaedorea metalica 26
Chamaedorea microspadix 20
Chamaedorea oblongata 27
Chamaedorea oreophila 25
Chamaedorea plumosa 26
Chamaedorea pochutlensis 26
Chamaedorea pochutlensis x graminifolia 25
Chamaedorea radicalis 22
Chamaedorea seifrizii 26
Chamaedorea stolonifera 26
Chamaerops humilis 16
Chamaerops humilis cerifera 16
Chambeyronia macrocarpa 30
Chuniophoenix hainansis 26
Coccothrinax argentata (provinence important) 26
Coccothrinax barbadensis 24
Coccothrinax crinata 26
Coccothrinax miraguama 26
Cocos nucifera 26
Copernicia alba 26
Copernicia fallaense 26
Copernicia glabrescens 26
Copernicia hospita 26
Copernicia macroglossa 24
Copernicia prunifera (inexplainably hardy) 26
Corypha elata 26
Corypha umbraculifera 26
Cryosophila stauracantha 26
Cyphophoenix nucele 26
Dypsis baronii 28
Dypsis decaryi 27
Dypsis decipiens 26
Dypsis lutescens 25
Dypsis onilahensis 29
Encephalartos ferox 25
Euterpe edulis 30
Gastrococos crispa 26
Guihaia argyrata 20
Guihaia grossefibrosa 20
Howea forsteriana 28
Hyphaene coriacea 27
Hyphaene dichotoma 27
Juania australis 21
Jubaea chilensis 15
Jubaeopsis caffra 25
Laccospadix australasica 26
Lepidorrachis mooreana 26
Licuala elegans 26
Licuala grandis 26
Licuala ramsayi 26
Licuala spinosa 26
Linospadix monostachya 26
Livistona australis 24
Livistona benthamii 24
Livistona boninensis (Syn. L. chin. ssp. subglossa)
Livistona carinensis 24
Livistona chinensis 24
Livistona chinensis v. subglobossa 24
Livistona decipiens 24
Livistona drudei 24
Livistona fulva 28
Livistona jenkinstana 26
Livistona mariae 25
Livistona muelleri 24
Livistona nitida 22
Livistona rigida 26
Livistona saribus 24
Livistona speciosa
Lytocaryum weddellianum 26
Nannorhops ritchiana 'Iran Silver' and 'Kashmir' 16
Nannorrhops ritchiana 15
Nannorrhops ritchiana 'Silver' 15
Normanbya normanbyi 26
Orbignya phalerata 26
Parajubaea cocoides 26
Parajubaea sunkha 25
Parajubaea torallyi 23
Phoenix acaulis 24
Phoenix canariensis 18
Phoenix canariensis x dactylifera 18
Phoenix dactylifera 20
Phoenix loureiroi v hanceana 26
Phoenix loureiroi v humilis 20
Phoenix loureiroi v loureirii 26
Phoenix loureiroi v pedunculata 20
Phoenix pusilla x roebelenii 26
Phoenix reclinata 22
Phoenix reclinata x roebelenii 24
Phoenix reclinata x rupicola
Phoenix roebelenii 22 ,NFT
Phoenix roebelenii v reasoneri 27
Phoenix roebelenii x canariensis 24
Phoenix rupicola 26
Phoenix sylvestris 18
Phoenix sylvestris v robusta 18
Phoenix theophrasti 20
Phoenix zeylanica
Plectocomia himilayana 24
Pritchardia beccariana 26
Pritchardia hildebrandii 26
Pritchardia minor 29
Pseudophoenix sargentii 26
Ptychosperma microcarpum 26
Ravenea glauca 28
Ravenea madagascariensis 26
Ravenea rivularis 26
Ravenea robustior
Ravenea sambiranensis 26
Ravenea xerophila 26
Ravenea xerophila 26
Rhapidophyllum hystrix 16
Rhapis excelsa 24
Rhapis humilis 20
Rhapis laosensis 26
Rhapis multifidia 24
Rhapis subtitlus 26
Rhopalostylis sapida 26
Rhopalostylis sapida v Chatham 26
Roystonea regia 26
Roystonea borenquenia 26
Sabal "riverside" 8
Sabal bermudana 20
Sabal 'Birmingham' 5
Sabal blackburnia 20
Sabal 'Brazoria 10
Sabal causerium 20
Sabal domingensis 20
Sabal etonia 20
Sabal maritima 20
Sabal mauritiaformis 24
Sabal mexicana 20
Sabal minor 12
Sabal minor louisiana 5
Sabal palmetto 16
Sabal parviflora 26
Sabal pumos 25
Sabal 'Riverside' 8
Sabal rosei 20
Sabal Tamaulipas 5
Sabal uresana 10
Sabal uresana x mexicana 10
Sabal Xtexensis 20
Sabal yapa 26
Scheelea butryracea 26
Scheelea liebmanii 26
Schippia concolor 26
Serenoa repens 20
Serenoa repens ‘Azul' 20
Syagrus campicola
Syagrus comosa
Syagrus duartei
Syagrus flexuosa
Syagrus glaucescens
Syagrus harleyi 25
Syagrus pleioclada
Syagrus romanzoffiana 24
Syagrus sancona 26
Syagrus schizophylla 28
Syagrus yungasensis
Synechanthus fibrosus 26
Thrinax morrisii 26
Thrinax radiata 26
Thrinax radiata 26
Trachycarpus 'Bulgaria' 10
Trachycarpus campestris 10
Trachycarpus fortunei 10
Trachycarpus geminisectus 10
Trachycarpus latisectus 20
Trachycarpus 'manipur' 20
Trachycarpus martianus 20
Trachycarpus 'Naga Hills'
Trachycarpus nanus 10
Trachycarpus oreophilus 20
Trachycarpus princeps 20
Trachycarpus schizophylla
Trachycarpus sikkimensis 25
Trachycarpus takaghii (f T. wagnerianus x m T. fortunei ) 10
Trachycarpus takil 10
Trachycarpus wagnerianus 10
Trithrinax acanthocoma 23
Trithrinax brasiliensis 23
Trithrinax campestris 20
Trithrinax schizophylla 23
Wallichia caryotoides 25
Wallichia densiflora 26
Wallichia disticha 24
Washingtonia filifera 16
Washingtonia filifera x robusta 16
Washingtonia robusta 20
Wodyetia bifurcata (long shot) 27 ,NFT
Zombia antillaru 24

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South Central Louisiana, Coastal Influence
Hardiness Zone 9a, Heat Zone 8, Sunset Zone 28
Averages = rainfall 61". Low/H Averages i=January 60/40, July 90/72

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[Mauna Kea Cloudforest]

Are you listing the kill temperatures for seedlings? Could these be the survival ratings for Florida or elsewhere in the South for palms that aren't hardened off like they do in California? There is no way parajubaea cocoides are going to croak from temperatures below 26F. They survived 1990 in California at 14F. Not to mention they are massive palms and it would take a lot of cold to actually freeze enough to penetrate and kill. And livistona decipiens is known to be hardy to much lower temps than 24F. Parajubaea cocoides does burn at 26F, though.

King palms under cover survived at UC Santa Cruz Arboretum in 1990 with 22F, leaving gaping holes in the trunks, but subsequently were entirely un-damaged in the 1998 freeze at 25F for three nights in a row, growing under oaks that is. My king palms take 28F every few years without a scratch. They take 28F all over Southern California as well. That can't possibly be the kill temperatures.

I wonder if your list should be amended and correctly note the temperatures as the "damage temperature", not the kill temperature, the two are quite distinct. Looking at it conservatively, the palms you mention growing out in the open without any canopy would probably get some noticeable damage at the temperatures you list. King palms fully exposed to the night sky in California see frond damage at 27F during radiational freezes, as the fronds drop to far lower temperatures than the surrounding air temperature due to radiational losses. But 28F during a radiational freeze would hardly kill a king palm here. 24F does, but not 28F.

Just wondering how you got such "weak" temperature ratings. I had originally dismissed the original UK list other than noting the unusual hardiness of the Madagascar palms.

[Phoenikakias]

... or you have not yet realized the extent of the competition. Has it ever occured to you how some palms having been previously stagnant for several years start off in a spectacular way after non palmy competition has been removed? It has occured to me several times with citrus trees vs Arenga pinnata, prunus trees vs Wallichia spss, Sabal spss vs olive trees. Before removal palms had been looking healthy but very slow growing and one could be misled from this fact to the conclusion that the specific climate/microclimate was not favourable for faster growth.

More examples: Laurel vs Arenga and Ravenea, Schinus terebinthifolius vs Pritchardia, Pittosporum vs Rhapis.

[Phoenikakias]

Are you listing the kill temperatures for seedlings? Could these be the survival ratings for Florida or elsewhere in the South for palms that aren't hardened off like they do in California? There is no way parajubaea cocoides are going to croak from temperatures below 26F. They survived 1990 in California at 14F. Not to mention they are massive palms and it would take a lot of cold to actually freeze enough to penetrate and kill. And livistona decipiens is known to be hardy to much lower temps than 24F. Parajubaea cocoides does burn at 26F, though.

King palms under cover survived at UC Santa Cruz Arboretum in 1990 with 22F, leaving gaping holes in the trunks, but subsequently were entirely un-damaged in the 1998 freeze at 25F for three nights in a row, growing under oaks that is. My king palms take 28F every few years without a scratch. They take 28F all over Southern California as well. That can't possibly be the kill temperatures.

I wonder if your list should be amended and correctly note the temperatures as the "damage temperature", not the kill temperature, the two are quite distinct. Looking at it conservatively, the palms you mention growing out in the open without any canopy would probably get some noticeable damage at the temperatures you list. King palms fully exposed to the night sky in California see frond damage at 27F during radiational freezes, as the fronds drop to far lower temperatures than the surrounding air temperature due to radiational losses. But 28F during a radiational freeze would hardly kill a king palm here. 24F does, but not 28F.

Just wondering how you got such "weak" temperature ratings. I had originally dismissed the original UK list other than noting the unusual hardiness of the Madagascar palms.

-2 C (28.4 F) with snowfall for two days killed all my Queen palms and also a juvenile (with pinnate fronds already) P cocoides.

[Mauna Kea Cloudforest]

Are you listing the kill temperatures for seedlings? Could these be the survival ratings for Florida or elsewhere in the South for palms that aren't hardened off like they do in California? There is no way parajubaea cocoides are going to croak from temperatures below 26F. They survived 1990 in California at 14F. Not to mention they are massive palms and it would take a lot of cold to actually freeze enough to penetrate and kill. And livistona decipiens is known to be hardy to much lower temps than 24F. Parajubaea cocoides does burn at 26F, though.

King palms under cover survived at UC Santa Cruz Arboretum in 1990 with 22F, leaving gaping holes in the trunks, but subsequently were entirely un-damaged in the 1998 freeze at 25F for three nights in a row, growing under oaks that is. My king palms take 28F every few years without a scratch. They take 28F all over Southern California as well. That can't possibly be the kill temperatures.

I wonder if your list should be amended and correctly note the temperatures as the "damage temperature", not the kill temperature, the two are quite distinct. Looking at it conservatively, the palms you mention growing out in the open without any canopy would probably get some noticeable damage at the temperatures you list. King palms fully exposed to the night sky in California see frond damage at 27F during radiational freezes, as the fronds drop to far lower temperatures than the surrounding air temperature due to radiational losses. But 28F during a radiational freeze would hardly kill a king palm here. 24F does, but not 28F.

Just wondering how you got such "weak" temperature ratings. I had originally dismissed the original UK list other than noting the unusual hardiness of the Madagascar palms.

-2 C (28.4 F) with snowfall for two days killed all my Queen palms and also a juvenile (with pinnate fronds already) P cocoides.

Now I am very curious. My cocoides took 28F last Winter without any problems, only minor burn on the ends of some of the more exposed fronds. Queen palms here are planted all over California and many of them got exposed to low 20's (-4 to -5C ) in Southern California in 2007 and they recovered just fine. But -2C with snowfall = convective freeze. Did you get above freezing during the day? Most of the California ratings are based on radiational freezes where the air is super dry and skies are crystal clear so that the temperature drops very fast due to radiational losses. Freeze duration are usually 6-8 hours with above freezing temps during the day.

1990 was one of the worst freezes California ever saw with widespread low to mid 20's. Many palms at the Oakland palmetum got exposed to multiple nights of 25F but few if any got killed by that. In 1990, many colder microclimates dropped into the upper teens to low 20's, cold enough to defoliate queens and many other mature palms, but few died.

So obviously there must be a significant difference between a high dewpoint convective freeze versus a low dewpoint radiational freeze.

[Phoenikakias]

The difference is really vast! I do not know whether temps rose during daylight and how much (i was not there), but I suppose that even if they rose, that was barely above 0 C and for only a few hours. Snow never melted entirely for a couple of days and it was snowing relentlessly at that time. In colder places even CIDP and oleanders got burnt.

Edited March 5, 2013 by Phoenikakias

[Mauna Kea Cloudforest]

I saw the pictures of the middle East under snow this past Winter. This is way colder than what you normally experience.

OK. let's say your cocoides did get killed by -2C from two days and two nights of continuous -2C with snow. What about the queens?

Are you sure it was -2C only? If it was -2C with snow, I would think the snow would have helped to insulate. I am really surprised at the queen palms getting killed. If you told anyone in California -2C kills queens, people would just dismiss your data. So I am really trying to understand what happened there.

In fact, go look at http://www.palmtalk.org/forum/index.php?/topic/3191-syagrus-romanzoffiana/, there are people who experienced far worse cold than -2C with queens surviving.

You really need to ask yourself why your garden would be such an anomaly compared to the rest of the world. Here are my possible explanations:

1) It was much colder than -2C

2) Your palms were not queens but a more cold sensitive species

3) Your palms were young

4) Your palms were in pots and froze solid after 3 days of -2C with no daytime warming. Unfortunately, the only palm that I know to have cold hardy roots is trachycarpus fortunei. I really don't think there is any other palm that I know of that would tolerate frozen roots.

Either way, you should post your data to the hardiness threads of the respective palms, but make sure to use really accurate data, not some estimates that you are making based on weather stations nearby. If you were not there, then you don't really know what happened.

[sonoranfans]

I think we should specify what treatment was rendered to the palm after the freeze/snow. I have had palms freeze and pulled the spears, then treated with peroxide and daconil to kill a fungal infection, then they survived. If you do not treat a palm with a cold induced fungus, it very well may die when you could have saved it. Having snow on a parajubaea for a few days sounds like a possible fungus issue. Death by fungal infection is not necessarily a cold hardy problem, though the infection may have been brought on by cold and wet. I have at least 6 small palms that survived the 2010 2 night frost event only because I pulled the spears and treated with peroxide and daconil multiple times. Today they look great and are no longer small...

[sonoranfans]

its also true that length and duration of cold can be a critical factor in survival....

[Phoenikakias]

I saw the pictures of the middle East under snow this past Winter. This is way colder than what you normally experience.

OK. let's say your cocoides did get killed by -2C from two days and two nights of continuous -2C with snow. What about the queens?

Are you sure it was -2C only? If it was -2C with snow, I would think the snow would have helped to insulate. I am really surprised at the queen palms getting killed. If you told anyone in California -2C kills queens, people would just dismiss your data. So I am really trying to understand what happened there.

In fact, go look at http://www.palmtalk.org/forum/index.php?/topic/3191-syagrus-romanzoffiana/, there are people who experienced far worse cold than -2C with queens surviving.

You really need to ask yourself why your garden would be such an anomaly compared to the rest of the world. Here are my possible explanations:

1) It was much colder than -2C

2) Your palms were not queens but a more cold sensitive species

3) Your palms were young

4) Your palms were in pots and froze solid after 3 days of -2C with no daytime warming. Unfortunately, the only palm that I know to have cold hardy roots is trachycarpus fortunei. I really don't think there is any other palm that I know of that would tolerate frozen roots.

Either way, you should post your data to the hardiness threads of the respective palms, but make sure to use really accurate data, not some estimates that you are making based on weather stations nearby. If you were not there, then you don't really know what happened.

Actually I had a max-min thermometer left outside that had recorded -2 C. Besides an outplanted bizzi and a Pritchardia hillebrandii went through the cold spell with medium damages, this is a good indication that temps never fell significantly below -2 C. Additionally due to this cold spell three Phoenix roebelenii of mine with 1 1/2 foot high trunk each got fried also to death. Same with a Caryota ochlandra (this one had been potplanted). Arecastrum (in total three) had been outplanted already for two or three years before the coldspell and were half the size of the one I am growing now. Two of them were well rooted and one not. From the healthier specimens one had been grown from seed gathered in NZ. All got fried to death. MHO is that the only horticultural mistake regarding the Syagrus was the use of 3-1-3 + 1 fertlizer. All above mentioned palms were more or less of same growth stage and all outplanted approximately at the same time.

[sonoranfans]

medium damage from a bizzy is below -2C. My bizzies were just about untouched by -2.2C and hard frost...

[_Keith]

Are you listing the kill temperatures for seedlings? Could these be the survival ratings for Florida or elsewhere in the South for palms that aren't hardened off like they do in California? There is no way parajubaea cocoides are going to croak from temperatures below 26F. They survived 1990 in California at 14F. Not to mention they are massive palms and it would take a lot of cold to actually freeze enough to penetrate and kill. And livistona decipiens is known to be hardy to much lower temps than 24F. Parajubaea cocoides does burn at 26F, though.

King palms under cover survived at UC Santa Cruz Arboretum in 1990 with 22F, leaving gaping holes in the trunks, but subsequently were entirely un-damaged in the 1998 freeze at 25F for three nights in a row, growing under oaks that is. My king palms take 28F every few years without a scratch. They take 28F all over Southern California as well. That can't possibly be the kill temperatures.

I wonder if your list should be amended and correctly note the temperatures as the "damage temperature", not the kill temperature, the two are quite distinct. Looking at it conservatively, the palms you mention growing out in the open without any canopy would probably get some noticeable damage at the temperatures you list. King palms fully exposed to the night sky in California see frond damage at 27F during radiational freezes, as the fronds drop to far lower temperatures than the surrounding air temperature due to radiational losses. But 28F during a radiational freeze would hardly kill a king palm here. 24F does, but not 28F.

Just wondering how you got such "weak" temperature ratings. I had originally dismissed the original UK list other than noting the unusual hardiness of the Madagascar palms.

-2 C (28.4 F) with snowfall for two days killed all my Queen palms and also a juvenile (with pinnate fronds already) P cocoides.

There are so many factors as to nearly make a list that one I made years ago fairly useless. That is why I quit updating it. For example the queens in this area endured 3 nights in a row 20,19,21 degrees and not a one died. Things like humidity, rain, length of time at a certain temperature, health, preceding weather and following weather can all make a few degrees meaningless. My Arenga engleri also endured the temperatures above with little damage, while _Rich's engleri went toes up in the mid 20s. As I said earlier, if you can find one in you area that has survived a decade consider it a reasonable safe bet, if not, it is a coin toss. And coin tosses can be a lot of fun, just don't invest more than you are willing to lose in the name of fun.

[Mauna Kea Cloudforest]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

[Phoenikakias]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

Sorry, I do not mean to confuse anyone more than I myself got confused. My report had been accurate and it seems that snow does frost damage report trickier for the Californians, who are never acquainted with it. For example what happens if snow melts partly to water during the second day of cold spell flowing inside to the growing point and in the following night temps fall again below 0 C and this water near the meristem freezes again?

[Phoenikakias]

Are you listing the kill temperatures for seedlings? Could these be the survival ratings for Florida or elsewhere in the South for palms that aren't hardened off like they do in California? There is no way parajubaea cocoides are going to croak from temperatures below 26F. They survived 1990 in California at 14F. Not to mention they are massive palms and it would take a lot of cold to actually freeze enough to penetrate and kill. And livistona decipiens is known to be hardy to much lower temps than 24F. Parajubaea cocoides does burn at 26F, though.

King palms under cover survived at UC Santa Cruz Arboretum in 1990 with 22F, leaving gaping holes in the trunks, but subsequently were entirely un-damaged in the 1998 freeze at 25F for three nights in a row, growing under oaks that is. My king palms take 28F every few years without a scratch. They take 28F all over Southern California as well. That can't possibly be the kill temperatures.

I wonder if your list should be amended and correctly note the temperatures as the "damage temperature", not the kill temperature, the two are quite distinct. Looking at it conservatively, the palms you mention growing out in the open without any canopy would probably get some noticeable damage at the temperatures you list. King palms fully exposed to the night sky in California see frond damage at 27F during radiational freezes, as the fronds drop to far lower temperatures than the surrounding air temperature due to radiational losses. But 28F during a radiational freeze would hardly kill a king palm here. 24F does, but not 28F.

Just wondering how you got such "weak" temperature ratings. I had originally dismissed the original UK list other than noting the unusual hardiness of the Madagascar palms.

-2 C (28.4 F) with snowfall for two days killed all my Queen palms and also a juvenile (with pinnate fronds already) P cocoides.

There are so many factors as to nearly make a list that one I made years ago fairly useless. That is why I quit updating it. For example the queens in this area endured 3 nights in a row 20,19,21 degrees and not a one died. Things like humidity, rain, length of time at a certain temperature, health, preceding weather and following weather can all make a few degrees meaningless. My Arenga engleri also endured the temperatures above with little damage, while _Rich's engleri went toes up in the mid 20s. As I said earlier, if you can find one in you area that has survived a decade consider it a reasonable safe bet, if not, it is a coin toss. And coin tosses can be a lot of fun, just don't invest more than you are willing to lose in the name of fun.

This is the most prudent attitude. Problem appears however if someone is generally a pioneer...

[Mauna Kea Cloudforest]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

Sorry, I do not mean to confuse anyone more than I myself got confused. My report had been accurate and it seems that snow does frost damage report trickier for the Californians, who are never acquainted with it. For example what happens if snow melts partly to water during the second day of cold spell flowing inside to the growing point and in the following night temps fall again below 0 C and this water near the meristem freezes again?

You are right. If there is snow and it melts and re-freezes, I can see how it would make a mess. We get snow here in California too but it's rare that it drops below 1,500 feet, let alone sea level. Even then it doesn't stick. 1972 was the last time there was measurable snow fall in California at sea level. And from what I hear, the 1972 snow fall was also associated with a freeze that was convective in nature and did a lot more damage at much higher temperatures. So it was probably a very similar scenario to what happened to the Middle East this past Winter.

[Phoenikakias]

Whenever one asks me about the climate im my property, I prefere to answer transitional between 9 and 10, if that makes any sense! I wish I could detremine the sunset zone, but I am not familiar with this scale.

[Phoenikakias]

Are you listing the kill temperatures for seedlings? Could these be the survival ratings for Florida or elsewhere in the South for palms that aren't hardened off like they do in California? There is no way parajubaea cocoides are going to croak from temperatures below 26F. They survived 1990 in California at 14F. Not to mention they are massive palms and it would take a lot of cold to actually freeze enough to penetrate and kill. And livistona decipiens is known to be hardy to much lower temps than 24F. Parajubaea cocoides does burn at 26F, though.

King palms under cover survived at UC Santa Cruz Arboretum in 1990 with 22F, leaving gaping holes in the trunks, but subsequently were entirely un-damaged in the 1998 freeze at 25F for three nights in a row, growing under oaks that is. My king palms take 28F every few years without a scratch. They take 28F all over Southern California as well. That can't possibly be the kill temperatures.

I wonder if your list should be amended and correctly note the temperatures as the "damage temperature", not the kill temperature, the two are quite distinct. Looking at it conservatively, the palms you mention growing out in the open without any canopy would probably get some noticeable damage at the temperatures you list. King palms fully exposed to the night sky in California see frond damage at 27F during radiational freezes, as the fronds drop to far lower temperatures than the surrounding air temperature due to radiational losses. But 28F during a radiational freeze would hardly kill a king palm here. 24F does, but not 28F.

Just wondering how you got such "weak" temperature ratings. I had originally dismissed the original UK list other than noting the unusual hardiness of the Madagascar palms.

-2 C (28.4 F) with snowfall for two days killed all my Queen palms and also a juvenile (with pinnate fronds already) P cocoides.

There are so many factors as to nearly make a list that one I made years ago fairly useless. That is why I quit updating it. For example the queens in this area endured 3 nights in a row 20,19,21 degrees and not a one died. Things like humidity, rain, length of time at a certain temperature, health, preceding weather and following weather can all make a few degrees meaningless. My Arenga engleri also endured the temperatures above with little damage, while _Rich's engleri went toes up in the mid 20s. As I said earlier, if you can find one in you area that has survived a decade consider it a reasonable safe bet, if not, it is a coin toss. And coin tosses can be a lot of fun, just don't invest more than you are willing to lose in the name of fun.

I had a trunked Hybiscus rosa chinensis for more than 30 years outplanted. It almost kicked the bucket during the aforementioned freeze and next freeze after 4 years again with snow (but of substatially shorter duration-by noon of same day cold spell was over) finished it off. That was all the snow within 39 years. So what's the point of restricting the crucial time to a single decade?

[Kailua_Krish]

Whenever one asks me about the climate im my property, I prefere to answer transitional between 9 and 10, if that makes any sense! I wish I could detremine the sunset zone, but I am not familiar with this scale.

I have to do the same for my place, its a transitional area between 8 and 9. Unfortunately that means that its too hot to grow many of the plants rated to zone 8 but too cold for many of the zone 9s

-Krishna

[sonoranfans]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

I disagree about bizzies not taking a frost, my emerging juveniles have taken 4 over the last 2 years with minimal damage to the lowest fronds at 28-30F. they are widely used as public plantings in parks and even neighborhood common areas in my area of florida, an area that is prone to frosts but has a dry winter season, like the natural habitat of bismarckia. Bismarcks are probably not planted in northern california because they dont like cold and wet and relish heat. A bizzie with wet feet in winter has quite a bit less cold resistance. The inland areas in norcal that get enough heat to grow a bizzie properly, like gilroy, get too cold in winter, and the coastal 9b/10a areas arent hot or sunny enough in summer for a bizzie to be healthy and they get pretty wet in winter.

Edited March 6, 2013 by sonoranfans

[Phoenikakias]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

I disagree about bizzies not taking a frost, my emerging juveniles have taken 4 over the last 2 years with minimal damage to the lowest fronds at 28-30F. they are widely used as public plantings in parks and even neighborhood common areas in my area of florida, an area that is prone to frosts but has a dry winter season, like the natural habitat of bismarckia. Bismarcks are probably not planted in northern california because they dont like cold and wet and relish heat. A bizzie with wet feet in winter has quite a bit less cold resistance. The inland areas in norcal that get enough heat to grow a bizzie properly, like gilroy, get too cold in winter, and the coastal 9b/10a areas arent hot or sunny enough in summer for a bizzie to be healthy and they get pretty wet in winter.

I tend to agree. USDA zones are not a safe touchstone for selction of promising palms in a specific area. What are the chances of recovery if a bizzi has a spearpull but retais all its older fronds? Could it ts push a new spear a year after spearpull?

Edited March 6, 2013 by Phoenikakias

[sonoranfans]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

I disagree about bizzies not taking a frost, my emerging juveniles have taken 4 over the last 2 years with minimal damage to the lowest fronds at 28-30F. they are widely used as public plantings in parks and even neighborhood common areas in my area of florida, an area that is prone to frosts but has a dry winter season, like the natural habitat of bismarckia. Bismarcks are probably not planted in northern california because they dont like cold and wet and relish heat. A bizzie with wet feet in winter has quite a bit less cold resistance. The inland areas in norcal that get enough heat to grow a bizzie properly, like gilroy, get too cold in winter, and the coastal 9b/10a areas arent hot or sunny enough in summer for a bizzie to be healthy and they get pretty wet in winter.

I tend to agree. USDA zones are not a safe touchstone for selction of promising palms in a specific area. What are the chances of recovery if a bizzi has a spearpull but retais all its older fronds? Could it ts push a new spear a year after spearpull?

Konstantinos,

The freeze damage section of this forum has some great information. The bismarckia section has lots of grower experiences, they are easily zone 9b palms, but in my experience they do like lots of heat in summer and a dry winter. Any time I have a good palm spear burn, after the first week, I tug at the spear every few days to see if it will pull. If it is going to have spear pull, you want to pull it as soon as possible and put hydrogen peroxide down the shoot to treat fungus. after that you put daconil or another effective fungicide down there. Repeat this every week or so 3-4 x. I have saved probably 10 palms this way after spear pull. The same specie palms that I didnt get the the spear pull soon enough(pull it out and treat), or arent treated, often die. Check out post 47/48 in this link, where "Freakypalmguy" cut off his bizzie at the trunk and it came back. Its a radical treatment, but it worked by probably removing the fungal infected parts. Once a bismarckia develops a subterranean structure(2-3 yrs) it will reach its potential cold hardiness. Also when you read of a reported temperature with overhead protection, be skeptical. Usually the temp under the protection is much warmer, up to 7 degrees F(4C) warmer in a radiational cooling event. Here is the link

http://www.palmtalk.org/forum/index.php?/topic/2996-bismarkia-nobilis/page-2

[Phoenikakias]

Much obliged from your comprehensive reply. My bizzi has fallen indirectly victim to rpw and paysandisia cause of excessive preventive spraying. But, using medical terminology, situation seems stabilized, in fact I think that trunk has fattened up a bit, though after spearpull (and also two of the youngest leaves) still no new spear on horizon but older leaves look very vivid and... perky. I followed exactly the same procedure you have described plus some covering of the cavity during rainy days. So there is still some hope!

[Mauna Kea Cloudforest]

This is becoming even more and more puzzling by the minute. A queen being less hardy than a p. hillebrandii? Something is seriously fishy here. It's very clear we are not getting the full story. p. hillebrandii has no cold hardiness whatsoever, it fries at 30F, snow at -2C would most definitely kill it cold. Mine starts showing damage at 32F. Bismarks are actually not widely planted in Northern California because they can't take the frost. But queens are everywhere because they can take the frost no problem. None of this freeze report makes any sense whatsoever. Have you considered that perhaps your palms were infected with some pathogen and the snow was just too much.

Anyway, I am going to stop trying to figure out this one. It's not making sense to me.

I disagree about bizzies not taking a frost, my emerging juveniles have taken 4 over the last 2 years with minimal damage to the lowest fronds at 28-30F. they are widely used as public plantings in parks and even neighborhood common areas in my area of florida, an area that is prone to frosts but has a dry winter season, like the natural habitat of bismarckia. Bismarcks are probably not planted in northern california because they dont like cold and wet and relish heat. A bizzie with wet feet in winter has quite a bit less cold resistance. The inland areas in norcal that get enough heat to grow a bizzie properly, like gilroy, get too cold in winter, and the coastal 9b/10a areas arent hot or sunny enough in summer for a bizzie to be healthy and they get pretty wet in winter.

There are practically no public biz plantings in California, even in Southern California where there are frost free areas that also get plenty of heat. It's not because biz require heat, it's because they're just not well known. They are considered too frost sensitive in California, whether this is true or not is a different story altogether, but that is the perception.

They grow fine in the warmer thermal belts of Norcal, and I even saw one in Grover Beach 3 bocks from the ocean that looked great. But they're probably not for San Francisco or Half Moon Bay. The blue form is supposed to be hardy to 22F so they should do fine in places like San Jose and other inland Bay area places.