Cold-hardy citrus
Introduction ''Ichang papeda'', a citrus variety known for its cold tolerance'''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 . 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.
Varieties Varieties of true citrus considered cold-hardy, ordered from most to least hardy:  Name Binomial Hardiness Edibility Notes Trifoliate orange ''Citrus trifoliata''  Inedible fresh Used as rootstock and will freely hybridize with other citrus  Ichang papeda ''Citrus cavaleriei''  Inedible fresh Parent to a number of hybrids, including the yuzu, sudachi, ichang lemon/shangjuan, and others Jiouyuezao mandarin ''Citrus reticulata'' 'Jiouyuezao'  Edible Long cultivated in China Changsha mandarin ''Citrus reticulata'' 'Changsha'  Edible but seedy Long cultivated in China Kumquat ''Citrus japonica''  Edible Fruit eaten whole with a sweet skin and sour pulp Desert lime ''Citrus glauca''   Edible, Used in cooking. Fruit eaten whole Satsuma ''Citrus reticulata'' 'Unshiu', syn. ''Citrus unshiu''  Edible; excellent Long cultivated in China=== Interspecific hybrids ===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  Edible 'Changsha' citrandarin is the hardiest citrus hybrid Citrange ''Citrus × sinensis'' × ''Citrus trifoliata''  Semi-edible 'Rusk' is considered the most edible citrange Citrangequat ''Citrus japonica'' × Citrange  Edible 'Thomasville' is considered the most edible citrangequat Citrumelo ''Citrus × paradisi'' × ''Citrus trifoliata''  Semi-edible 'Dunstan' is considered the most edible citrumelo Kabosu ''Citrus cavaleriei'' × ''Citrus x aurantium''  Edible, Used in cooking Long cultivated in Japan Shuangjuan (Ichang lemon) ''Citrus cavaleriei'' × ''Citrus maxima''  Edible, Used in cooking Long cultivated in China Yuzu ''Citrus cavaleriei'' × ''Citrus reticulata''  Edible, Used in cooking Originally cultivated in China; spread to Japan, where many cultivars have been developed Sudachi ''Citrus x junos'' × ''Citrus leiocarpa''  Edible, Used in cooking Long cultivated in Japan Orangequat ''Citrus sinensis'' × ''Citrus japonica''  Edible 'Nippon' is favored for edibility and hardiness  Rangpur lime ''Citrus medica'' × ''Citrus reticulata''  Edible, Used in cooking Long cultivated in South Asia Calamondin ''Citrus reticulata'' × ''Citrus japonica''  Edible, Used in cooking  Long cultivated in the Philippines Chinotto ''Citrus x aurantium'' var. 'myrtifolia'   Edible. Used in cooking, too bitter to eat raw Long cultivated in Southern Italy, Malta and Libya
See also * Citrus rootstock
References
External links * ''The Citrus Industry'' Volume 1 & 2