Cold-hardy citrus


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 or hybrids 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 be cooked to make marmalade.

Varieties

Varieties of true citrus considered cold-hardy, ordered from most to least hardy:
NameBinomialHardinessEdibilityNotes
Trifoliate orangePoncirus trifoliataInedible freshUsed as rootstock and will freely hybridize with true citrus.
Ichang papedaCitrus cavalerieiInedible freshParent to a number of hybrids, including the yuzu, sudachi, ichang lemon/shangjuan, and others.
Jiouyuezao mandarinCitrus reticulata 'Jiouyuezao')EdibleLong cultivated in China
KumquatFortunella japonicaEdibleFruit eaten whole with a sweet skin and sour pulp.
Changsha mandarinCitrus reticulata 'Changsha'Edible but seedy.Long cultivated in China
ChinottoCitrus myrtifoliaEdible. Used in cooking, too bitter to eat raw.Long cultivated in Southern Italy, Malta and Libya.
SatsumaCitrus reticulata 'Unshiu', syn. Citrus unshiuEdible; ExcellentLong cultivated in China

Interspecific hybrids

Interspecific hybrid varieties considered cold-hardy, ordered from most to least hardy:
NameBinomialHardinessEdibilityNotes
CitrandarinSemi-edible'Dunstan' is considered the most edible citrumelo.
CitrangeSemi-edible'Rusk' is considered the most edible citrange.
CitrangequatEdible'Thomasville' is considered the most edible citrangequat.
YuzuUsed in cooking.Long cultivated in Japan, where many cultivars have been developed.
OrangequatEdible'Nippon' is favored for edibility and hardiness.