Changsha

Changsha is one of the hardiest of the mandarins.  May have C. ichangensis in background.  Survives short freezes of  13°F, -11°C F with no loss of leaves, reports it survives 6°F, -14°C [4] p. 28 and also dying at that same temperature [5] .  Generally considered hardy to 10°F, -12°C [4] p. 14.  It is very seedy and the flavor is bland, low acid.  Honey Changsha is a selection with better flavor, at least some seedlings are zygotic. It has about 25 seeds per fruit.

Honey Changsha

Seedless Changsha News 

In 2003 Dr. Wayne Hanna at the University of Georgia Tifton Campus started working on a seedless Changsha.[1]  He exposed seed to gamma radiation to induce sterility.  Dr. Hanna[2] and his fruit[3].  Dr. Hanna at the 2013 Citrus Expo in Alabama said it was still a couple of years away from introduction.

A seedless Changsha, cold hardy seedless lemon and seedless grapefruit is now available  
but only for sale in Georgia.

• ‘Sweet Frost’ is an irradiated Changsha mandarin with two to three seeds per fruit. It has a Brix range of 11-12, it is very easy peel, well-colored, and matures (in GA) in November or December.
• ‘Grand Frost’ is an irradiated Ichang lemon. This is a large lemon (25 centimeters to 28 cm in circumference) with about 8 Brix and high juice content. It has nice, bright-yellow color and a maturity range of November through January.
• ‘Pink Frost’ is a red grapefruit, with characteristics not dissimilar to ‘Ruby Red,’ but with somewhat deeper color. It averages 30 cm to 35 cm in circumference, has Brix 8-11, and matures (in GA) November through March. It averages three seeds per fruit. This variety was identified in Georgia. It was a high seed fruit, with approximately 60 seeds before being irradiated.[4]

Razzlequat or Coachella Eremolemon

Citrus (Eremocitrus) glauca x ?

Hardy at least to 13°F, -11°C

There is a lot of confusion as to the origin of this variety.  It was named Razzlequat in the Oregon Exotics Catalog, which suggests one parent is a kumquat, but the catalog's author identified it as 'Eremocitrus x C. Limona Meyer'.[1]   Mislabeling continued in 'Hardy Citrus of the Southeast' Kumquat x Eremocitrus glauca[2] p.26.

Swingle called it a "Eremolemon [Eremocitrus glauca X Citrus limon 'Meyer lemon']." [3] and the UCR website takes its information from him [4]

It now appears that it is a cross with a grapefruit.[5]

Hardiness testing in Savannah Georgia showed it to be one of the hardiest varieties tested.   Surviving 13°F, -11°C with poor acclimation better than Yuzu and Ichang papeda.[6] Since Yuzu is considered to be hardy to 10°F, -12°C it should survive lower temperatures.  Perhaps it maintains dormancy longer than Yuzu and Ichang papeda when exposed to warmer weather. 

Plant is very thorny.  Flavor is sour. Very rare.

Pictures courtesy Virginia Fruit Grower
 

Virginia Fruit Grower Video

 

Ten-Degree Tangerine aka Clem-Yuz 2-2 or Clem-Yuz 3-3

1/2 Clementine, 1/2 Yuzu

Citrus reticulata x (C. ichangensis x C. reticulata)

Originally thought to refer to Clem-Yuz 3-3, there is confusion and it may also refer to Clem-Yuz 2-2.

Hardy to 10°F, -12°C perhaps to 5°F, -15

°C

Ten-Degree Tangerine may refer to either Clem-Yuz 2-2 or Clem-Yuz 3-3.  Clem-Yuz 2-2 is a much earlier ripening fruit and is said to be better tasting by one grower.  Clem-Yuz 3-3 can have a kerosene aftertaste.  However Dr. Brown the originator preferred 3-3

"This plant, otherwise know as Clem-Yuz 3-3 is one of a number of Clementine X Yuzu hybrids produced by Dr. Brown during the late 1960s...semi-deciduous...blooming and fruiting after 80 to 130 hours of continuous subfreezing weather with minimum temperatures of 10 F or lower...Fruit ripens relatively late, in mid-December, in Texas, when it attains quality better than that of supermarket tangerines...the fruit matures into a sprightly flavored tangerine"[1] p. 30
“The rind is orange and smooth...If self pollinated the fruit is nearly seedless.  But otherwise has 8-20 large, plump seeds per fruit, seeds appear to be a mix of monoembryonic and polyembryonic types...unripe fruit has an excellent lime-like flavor...(fruit) will keep for several months under refrigeration.”[2] p. 48 

At the Stan Mckenzie orchard in SC in March 2014, Ten-Degree Tangerine looked much better than Owari.  Trees still had their leaves, while Owari was mostly defoliated with stem die back.   

Note on 11/13/15  Picked the only fruit on 3-3.  Small and immature.  Skin color half turned from green to yellow. Interior color pale yellow.  Flavor very good, tastes as good as some store bought, brix 9.5.  Fruit was cross-pollinated. 12 seed. 

Single Clem Yuz 3-3 picked on December 15, 2016.  Color is not as orange as expected based on Dr. Brown description. Skin is smooth, compare with 
2-2


December 1, 2017, picked 1 fruit.  Brix 12.  Slightly tart, but good flavor. 





Clem-Yuz 2-2

The fruit is large tangerine size...juice is sweetish with a mild tangerine flavor that has a trace of kerosene; but there is no gum or bitterness.  Each segment has 1-2 seeds which are moderately large...Although the peel is corky, it is edible because it lacks the intense acrid bitterness seen in most citrus...Fruit is borne at branch tips near the outside of the tree, and is ripe by mid-October.

At best, fruit is a pale, juicy, seedy, low-flavored mandarin, but in many years it is dry and juiceless.  Tree is productive, withstands 5 - 10 degrees F.[2]  pp. 48 & 50  

An experienced hobbiest believes this is an excellent flavored fruit,  and the early ripening period is an added benefit. Personal observation, pleasant tasting.

2-2, very loose skin, photo taken November 19, 2016

Taitri

Citrus trifoliata x C. taiwanica

Hardy to 0°F, -18°C

"A hybrid known as Tatri, of seed acquired by Bill Chapman from Dr. Soost, then at U.C Riverside, is known to be C. taiwanica x P. trifoliata, and quite hardy.  My seven in Franklin survived with only minor damage at one degree above zero, likewise one at Houston at five degrees above.  Bill Chapman agrees the juice of this hybrid is sweeter with less of the objectionable flavor than any other 50% P. trifoliata hybrid.  A recent re-test comparing Taitri#1 with Citemsweet (both were admittedly frost damaged to 23° F and only Taitri #1 had fully colored) found them quite close, indistinguishable to my taste.  No positive or negative comments arose in a taste test in Houston on November 30, 1991. "[1] p. 14

Some seeds are zygotic.

This is a mild improvement, and not directly edible.  It does have some trifoliate scent but mostly lemon fragrance from the Tiawanica and luckily the resin, funk and oils are not present like in regular trifoliate.  Being deciduous it should be hardier much further north, probably hardier than other 50% hybrids that are not trifoliate.