Cold-hardy citrus is citrus with increased frost tolerance and which may be cultivated far beyond traditional citrus growing regions. Citrus species and citrus hybrids typically described as cold-hardy generally display an ability to withstand wintertime temperatures below −5 to −10 °C (23 to 14 °F). Cold-hardy citrus may be generally accepted 'true' species (e.g. Satsuma mandarin, kumquat) or hybrids (e.g. citrange) involving various other citrus species. All citrus fruits are technically edible, though some have bitter flavors often regarded as unpleasant, and this variability is also seen in cold-hardy citrus fruits. Those listed as "inedible fresh" or "semi-edible" can (like all citrus) be cooked to make marmalade.

Ichang papeda, a citrus variety known for its cold tolerance

Varieties

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Varieties of true citrus considered cold-hardy, ordered from most to least hardy:

Name Binomial Hardiness Edibility Notes
Trifoliate orange Citrus trifoliata −30 °C (−22 °F)[1] Inedible fresh Used as rootstock and will freely hybridize with other citrus
Ichang papeda Citrus cavaleriei −18 °C (0 °F) Inedible fresh Parent to a number of hybrids, including the yuzu, sudachi, ichang lemon/shangjuan, and others
Jiouyuezao mandarin Citrus reticulata 'Jiouyuezao' −13 °C (9 °F)[2] Edible Long cultivated in China
Changsha mandarin Citrus reticulata 'Changsha' −11 °C (12 °F) Edible but seedy Long cultivated in China
Kumquat Citrus japonica −10 °C (14 °F)[3] Edible Fruit eaten whole with a sweet skin and sour pulp
Desert lime Citrus glauca −10 °C (14 °F) Edible, Used in cooking. Fruit eaten whole
Satsuma Citrus reticulata 'Unshiu', syn. Citrus unshiu short-term −6 °C (21 °F) Edible; excellent[4] Long cultivated in China

Interspecific hybrids

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Interspecific hybrid varieties considered cold-hardy, ordered from most to least hardy:

Name Binomial Hardiness Edibility Notes
Citrandarin Citrus reticulata × Citrus trifoliata e.g. Cultivar US852 −18 °C (0 °F) Edible 'Changsha' citrandarin is the hardiest citrus hybrid
Citrange Citrus × sinensis × Citrus trifoliata −18 °C (0 °F)[5] Semi-edible 'Rusk' is considered the most edible citrange
Citrangequat Citrus japonica × Citrange −15 °C (5 °F)[5] Edible 'Thomasville' is considered the most edible citrangequat
Citrumelo Citrus × paradisi × Citrus trifoliata −15 °C (5 °F) Semi-edible 'Dunstan' is considered the most edible citrumelo
Kabosu Citrus cavaleriei × Citrus x aurantium −12 °C (10 °F) Edible, Used in cooking Long cultivated in Japan
Shuangjuan (Ichang lemon) Citrus cavaleriei × Citrus maxima −12 °C (10 °F) Edible, Used in cooking Long cultivated in China
Yuzu Citrus cavaleriei × Citrus reticulata −12 °C (10 °F) Edible, Used in cooking Originally cultivated in China; spread to Japan, where many cultivars have been developed
Sudachi Citrus x junos × Citrus leiocarpa −12 °C (10 °F) Edible, Used in cooking Long cultivated in Japan
Orangequat Citrus sinensis × Citrus japonica −9 °C (16 °F) Edible 'Nippon' is favored for edibility and hardiness
Rangpur lime Citrus medica × Citrus reticulata −9 °C (16 °F) Edible, Used in cooking Long cultivated in South Asia
Calamondin Citrus reticulata × Citrus japonica −8 °C (18 °F) Edible, Used in cooking Long cultivated in the Philippines
Chinotto Citrus x aurantium var. 'myrtifolia' −8 °C (18 °F) Edible. Used in cooking, too bitter to eat raw Long cultivated in Southern Italy, Malta and Libya

See also

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References

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  1. ^ "Isolation of genes from cold acclimated Poncirus trifoliata and Citrus unshiu" (https://etd.auburn.edu/bitstream/handle/10415/737/ZHANG_CANKUI_23.pdf])
  2. ^ China/FAO Citrus Symposium "Mandarin-like Hybrids of Recent interest for Fresh Consumption. Problems and Ways of Control". FAO.
  3. ^ Sauls, J. W., & Jackson, L. K. Cold-Hardy Citrus for North Florida. Document FC-36[permanent dead link]. University of Florida, IFAS Extension.
  4. ^ Andersen, Peter C.; Ferguson, James J. "The Satsuma Mandarin". University of Florida, Institute of Food and Agricultural Sciences Extension. Retrieved 23 May 2020.
  5. ^ a b "Cold Hardy Citrus and Hybrids". Limette (Newsletter Citrus Friends Europe) 8: 1–2.
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