Cold-hardy citrus is
citrus
''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Lemon, lemons, grapefruits, pomelos, and lim ...
with increased
frost
Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a gas) ...
tolerance and which may be cultivated far beyond traditional citrus growing regions. Citrus
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
and
citrus hybrids
Citrus taxonomy refers to the botanical classification of the species, varieties, cultivars, and graft hybrids within the genus ''Citrus'' and related genera, found in cultivation and in the wild.
Citrus taxonomy is complex and controversial. ...
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
Kumquats (; zh, 金桔), or cumquats in Australian English, are a group of small fruit-bearing trees in the flowering plant family Rutaceae. Their taxonomy is disputed. They were previously classified as forming the now-historical genus ''For ...
) or hybrids (e.g.
citrange
The citrange (a portmanteau of ''citrus'' and ''orange'') is a citrus hybrid of the sweet orange and the trifoliate orange.
The purpose of this cross was to attempt to create a cold hardy citrus tree (which is the nature of a trifoliate), with d ...
) 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
Marmalade is a fruit preserve made from the juice and peel of citrus fruits boiled with sugar and water. The well-known version is made from bitter orange. It is also made from lemons, limes, grapefruits, mandarins, sweet oranges, bergamo ...
.
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:
See also
*
Citrus rootstock Citrus rootstock are plants used as rootstock for citrus plants. A rootstock plant must be compatible for scion grafting, and resistant to common threats, such as drought, frost, and common citrus diseases.
Principal rootstocks
Five types of rootst ...
References
External links
''The Citrus Industry'' Volume 1 & 2{{citrus
Citrus
Citrus hybrids
Lists of plants
Gardening aids