So in this zone you could grow all of this:
Rhapidophyllum hystrix: - 21°C
Nannorhops ritchiana: - 21°C
Sabal minor: -18°C
Trachycarpus takil: -18°C
Trachycarpus wagnerianus: -18°C
Trachycarpus fortunei: -18°C
Serenoa repens: -18°C
Trachycarpus martianus: -15°C
Trachycarpus nanus: -15C
Jubaea chilensis: -15°C
Chamaerops humilis var.cerifera: -15°C
Chamaerops humilis: -12°C
Sabal palmetto: -12°C
Butia capitata: -12°C
Butia eriospatha: -14°C
Butia yatay: -12°C
Brahea armata: -12°C
Trithrinax campestris: -12°C
Phoenix dactylifera: -12°C
Phoenix theophrastii: -12°C
Trachycarpus latisectus: -10°C
Washingtonia filifera: -10°C
Brahea edulis: -10°C
Sabal riverside: -10°C
Sabal bermudana: - 10°C
Sabal palmetto: -10°C
Phoenix canariensis: - 10°C
Butia archeri (-10°C)
Phoenix sylvestris: -10°C
Livistona australis: -10°C
Sabal etonia: -10°C
Washingtonia robusta: - 8C
Trachycarpus princeps: -8°C
Livistona chinensis: -8°C
Brahea brandegeei (-8°C)
Brahea dulcis (-8°C)
Trachycarpus oreophilus: -8°C
Trithrinax brasiliensis: -8°C
Syagrus romanzoffianum:-8°C
Sabal mexicana: -8°C
Acoelorraphe wrightii: -8°C
Arenga engleri: -8°C
Arenga micrantha: -8°C
Phoenix reclinata: -8°C
Caryota urens: -7°C
Syagrus romanzoffianum: -6°C
Livistona australis: -6°C
Caryota obtusa: -6°C
Caryota sp " Himalaya ": -6°C
Caryota sp." Mystery " : -6°C
Ceroxylon alpinum: -6°C
Ceroxylon quindiuense: -6°C
Chamaedorea radicalis: -6°C
Livistona decipiens: -6°C
Phoenix rupicola (-6°C)
Bismarckia nobilis: -5°C
Rhapis excelsa: -5°C
Parajubaea cocoides: -5°C
Rhopalostylis sapida: -5°C
And maybe:
Livistona decipiens: -4°C
Archontophoenix cunninghamiana: -4°C
Dypsis decaryi: -2°C
I want too

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I have usda zone 6b -17°C/-20°C
