Cold-hardy citrus
Cold hardy citrus is a general term describing citrus with increased frost tolerance 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.
Varieties
Varieties of true citrus considered cold hardy, ordered from most to least hardy:
Interspecific hybrids
Interspecific hybrid varieties considered cold hardy, ordered from most to least hardy:
References
External links
The Citrus Industry Volume 1 & 2