Palmpedia - Palm Grower's Guide:PALMPEDIA SPECIES ZONE SCALE

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Palmpedia is going to try a new way to rank and catagorize the cold hardiness of palms. Instead of trying to define the nebulous concept of low temperature limits and climatic zones, this will be a comparative rating of species. For example, if you see King palms growing in your neighborhood, then everything rated hardier on the SZS (Species Zone Scale), would be hardy for your area. Each zone will have a common palm as the "namesake" for the zone indicating the least hardy palm in that category. Therefore, if you see Queen Palms across the street, anything in the Queen Zone (SZS #2A) and below will be hardy enough to survive for you.

This will always be a fluid document, so jump in and add your 2 cents of wisdom.

SPECIES ZONE SCALE #1 - HARDY PALMS

SZS #1A: The Canary Zone

• Sabal minor - Phoenix canariensis

SZS #1B: The Washingtonia Zone

• Phoenix canariensis - Washingtonia robusta

SPECIES ZONE SCALE #2 - SEMI-HARDY PALMS

SZS #2A: The Queen Zone

• Washingtonia robusta - Syagrus romanzoffiana

SZS #2B: The Pigmy Date Zone

• Syagrus romanzoffiana - Phoenix roebelinii

SPECIES ZONE SCALE #3 - TEMPERATE PALMS

SZS #3A: The King Zone

Phoenix roebellini - Archontophoenix cunninghamia

SZS #3B: The Kentia Zone

Archontophoenix cunninghamia - Howea forsteriana To me, this is a pretty narrow zone, as I see very little difference in hardiness between these two species... both are equally fried by temps in the high 20s. I would probably put Rhopalostylis in here, too. But I can't think of too many other palms that would squeeze in between two palms I consider about the same hardiness. I have yet to see a freeze where one got killed and the other did not. Here in California, these two palms are on the borderline of 9b-10a.

Do these zones only take into consideration of cold hardiness? What about heat hardiness, drought hardiness, wind hardiness, low-light hardiness or hardiness to bud damage? I certainly would rate Howeas as more hardy than Kings to heat and bud damage, and possibly drought hardiness. Low light hardiness Howeas far exceed kings (and just about anything). They may even be a bit more wind hardy, though salty winds trash both species here in So Cal pretty badly- perhaps Kings more so than Howeas.

In terms of cold hardiness, I would rate most other Archontophoenix less hardy than these two, but hardier than Wodyetias... but that makes them fall inbetween these proposed zones. Is there a zone 3c?

SPECIES ZONE SCALE #4 - SUB-TROPICAL PALMS

SZS #4A: The Foxtail Zone

Howea forsteriana - Wodyetia bifurcata Except for the next zone, I would say this zone has the most palms in it that can grow in southern California (assuming this is a cold hardy zone scale, and other hardiness parameters don't count)... This would be the equivalent, perhaps, of a California zone 10a (which has absolutely no relationship to a zone 10a in Florida).

Some palms that would fit in this zone include Acanthophoenix crinita, Actinokentia divaricata, Archontophoenix alexandrae, many of the Attaleas, Basselinia favieri and gracilis, Burretiokentia hapala, Caryota mitis, Caryota rumphiana, Ceroxylon quindiuense, Chamaedorea brachypoda, Chamaedorea hooperiana, Chamaedorea klotzschiana, Chamaedorea metallica, Chamaedorea nationsiana, Chamaedorea oblongata, Chamaedorea siefrizii, Chamaedorea stolonifera, Cryosophila warscewiczii, Cyphophoenix nucele, Dypsis ambositrae (not the real thing), Dypsis baronii, Dypsis decaryi, Dypsis leptocheilos, Dypsis utilis, Hedyscepe canterburyana, Howea belmoreana, Hyphaene coriacea, Hyphaene theibaica, Kentiopsis oliviformis, Laccospadix australasica, Licuala ramsayi, Linospadix monostachya, Livistona victoriae, Pinanga coronata, Pinanga gracilis, Prestoea 'montana', Pritchardia kaale, Pritchardia lanaiensis, Pritchardia minor, Pritchardia remota, Ptychosperma caryotoides, Ptychosperma elegans, Raphia farinifera, Ravenea glauca, Ravenea hildebrantii, Ravenea rivularis, Rhopalostylis baueri and sapida, Roystonea regia, Sabal mauritiiformis, Sabal yapa, Syagrus glaucescens, Syagrus sancona, Syagrus schizophylla and Trachycarpus latisectus to name a few. How I would compare all these to each other, I have no idea... I cannot detect any appreciable difference between them.

SZS #4B: The Manila Zone

Wodyetia bifurcata - Adonidia merrillii This zone has to be one where the bulk of palms that can survive in California live. It would probably be the equivalent of a zone 10a-10b. No idea how this translates into Florida zones, though. Most southern Californians can eke a Wodyetia along, while none can make an Adonidia survive more than a winter or two.

Palms I would put in this zone include: Aiphanes aculeata, Aiphanese lindeniana, Allschmidia glabrata, Areca triandra, Arenga caudata, Arenga pinnata (though maybe zone 4a?), Astrocaryum mexicanum, Basselinia pancheri, Beccariophoenix window form, Burretiokentia vielardia and koghiensis, Calamus australis, Calyptronoma (Calyptrogyne) sp., Carpentaria accuminata, Caryota no, Ceroxylon alpinum, Ceroxylon vogelianum, Chamaedorea amabilis, Chamaedorea correae, Chamaedorea dammeriana, Chamaedorea deckeriana, Chamaedorea fragrans, Chamaedorea geonomiformis, Chamaedorea minima, Chamaedorea nubium, Chamaedorea palmeriana, Chamaedorea rigida, Chamaedorea robertii, Chamaedorea rosteniorum, Chamaedorea schiediana, Chamaedorea sullivanorum, Chamaedorea tenella, Chamaedorea tuerckheimii, Chambeyronias (all), Cliostigma harlandii and savoryanum, Cocothrinax spissa, Cocos nucifera, Copernicia hospita, Copernicia rigida, Copernicia macroglossa (barely fits in this zone.. nearly equal to A merrillii here), Cyphosperma balanse, Desmoncus species, Dictyospema album, Dypsis albofarinosa, Dypsis Bejofa, Dypsis cabadae, Dypsis crinita, Dypsis fibrosa, Dypsis lanceolata, Dypsis lastelliana, Dypsis madagascariensis, Dypsis nodifera, Dypsis pembana, Dypsis pinnatifrons, Dypsis psammophila, Dypsis pusilla, Dypsis rivularis, Dypsis sahanofensis, Dypsis sanctamariae, Gastrococos crispa, Gaussia attenuata and princeps, Geonoma congesta, Geonoma interrupta, Geonoma undata, Hyophorbes (all), Iguanura wallichiana, Joey palms, Kentiopsis magnifica and piersoniorum, Kerriodoxa elegans, Latanias (all), Lepidorrhachis mooreana, Licuala peltata, Licuala radula, Linospadix minor and palmeriana, Livistona inermis, Livistona minor, Marojejyas, Pinanga phillipinensis, Pinanga javana, Polyandrococos caudescens, Pritchardia martii, Pseudophoenix (all that can grow here), Ptychosperma burretianum, Ptychococus lepidota, Ptychosperma macarthuri, Ptychosperma salomonense, Raphia australis, Ravenea sambiranensis, Reinhardtia gracilis and simplex, Rhapis laoensis, Roystonea altissima, Roystonea oleracea, Satakentia, Syagrus amara, Syagrus botryophora, Syagrus pseudococos, Thrinax (all), Veitchia arecina, Veitchia joannis, Vietchia filifera, Zombia antillarum... to name a few.

This zone is quite wide, and separating these in order of hardiness would be much less of a feat... maybe later.

SPECIES ZONE SCALE #5 - TROPICAL PALMS

SZS #5A: The Coco Zone

Adonidia merrillii - Cocos nucifera

SZS #5B: The Lipstick Zone

Cocos nucifera - Cyrtostachys renda