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:

Name Hardiness Edibility Notes
Trifoliate orange (Poncirus trifoliata) −30 °C (−22 °F)[1] Inedible fresh Used as rootstock and will freely hybridize with true citrus.
Ichang papeda (Citrus ichangensis) −15 °C (5 °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
Kumquat (Citrus japonica) −12 °C (10 °F)[3] Edible Fruit eaten whole with a sweet skin and sour pulp.
Changsha mandarin (Citrus reticulata 'Changsha') −11 °C (12 °F) Edible but seedy. Long cultivated in China
Satsuma (Citrus reticulata 'Unshiu', syn. Citrus unshiu) −10 °C (14 °F)[1] Edible; Excellent Long cultivated in China
Chinotto (Citrus myrtifolia) −8 °C (18 °F) Used in cooking, too bitter to eat raw. Edible Long cultivated in Southern Italy, Malta and Libya.

Interspecific hybrids

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

Name Hardiness Edibility Notes
Citrandarin (Citrus reticulata × Poncirus trifoliata) −18 °C (0 °F) Semi-edible 'Changsha' citrandarin is the hardiest citrus hybrid.
Citrumelo (Citrus × paradisi × Poncirus trifoliata) −15 °C (5 °F) Semi-edible 'Dunstan' is considered the most edible citrumelo.
Citrange (Citrus × sinensis × Poncirus trifoliata) −15 °C (5 °F)[4] Semi-edible 'Rusk' is considered the most edible citrange.
Citrangequat (Citrus japonica × Citrange) −15 °C (5 °F)[4] Edible 'Thomasville' is considered the most edible citrangequat.
Yuzu (Citrus ichangensis × Citrus reticulata) −12 °C (10 °F) Used in cooking. Long cultivated in Japan, where many cultivars have been developed.
Orangequat (Citrus sinensis × Citrus japonica) −9 °C (16 °F) Edible 'Nippon' is favored for edibility and hardiness.

References

  1. 1 2 Isolation of genes from cold acclimated Poncirus trifoliata and Citrus unshiu (Abstract)
  2. China/FAO Citrus Symposium Mandarin-like Hybrids of Recent interest for Fresh Consumption. Problems and Ways of Control.
  3. Sauls, J. W., & Jackson, L. K. Cold-Hardy Citrus for North Florida. Document FC-36. University of Florida, IFAS Extension.
  4. 1 2 Cold Hardy Citrus and Hybrids. Limette (Newsletter Citrus Friends Europe) 8: 1–2.
This article is issued from Wikipedia - version of the 10/8/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.