How Hardy Are Cold Hardy Citrus Varieties

Hardy To About -15'F (-26'C)
Trifoliate Orange (Poncirus trifoliata)

Hardy To About 0'F (-18'C)
Ichang Papeda (Citrus inchangensis)

Hardy To About 5'F (-15'C)
Citrandarins
Citranges
Citrumelos
Nansho Daidai Sour Orange

Hardy to About 10'F (-12'C)
Bloomsweet Grapefruit
Citrangequats
ClemYuzu hybrids
Ichang Lemon
Yuzu
Yuzuquat
Yuzvange
Ten Degree Kumquat
Nippon Oranequat
Changsha Mandarin
Juanita Tangerine

Hardy To The Low Teens (-11'C)
Keraji Mandarin
Seville Sour Orange
Smooth Flat Seville Sour Orange

Hardy To About 15'F (-9'C)
Kumquats
Procimequat
Sunquat & Marmaladequat
Calamandarin
Sour Oranges
Sanbokan Grapefruit
Eustis Limequat

Hardy To The Upper Teens (-8'C)
Satsuma
Long Huang Kat Mandarin

Hardy To About 20'F (-7'C)
Sweet Oranges
Duncan, Marsh & Ruby Red Grapefruits
Meyer Lemon
Ukitsu Lemon

Factors affecting hardiness are minimum temperature, freeze duration, conditions before the freeze, soil moisture and wind protection. Citrus
are usually hardier if they are healthy, well watered and fully dormant
when cold arrives. Temperatures listed here are approximate, and indicate where fully dormant plans begin to experience significant damage. ("Hardy Citrus For The Southeast.)

Hi Have you ever tried any of these???

I live in Mass and I am interested in growing some of these outside. I do understand that w/o protection that they stand no chance, but with 300 or so Watts, I think that I can get about 40 degrees above ambient which should be sufficient to keep these alive in my area.

Has anyone else tried this in the "north"

Thanks Frank

I don't have all of these but I do grow quite a few of them. Which varieties are you interested receiving information on?

Hi

I am thinking of growing the Yuzu, 10 deg tangerine and the Thomasville citrangequat.

Really anything that can be eaten out of hand and is cold hardy.

Where do you live?

Thanks Frank

Of the three citrus that you mention I would suggest you grow a Juanita Tangerine rather than the 10 Degree Tangerine. The Juanita Tangerine has mush better tasting fruit. It is a sweet tangerine with no off flavors with very good quality. No matter where you live, it is important to pick a variety that matures fruit as early as possible. The fruit of the Juanita Tangerine matures around Thanksgiving. This tangerine astonishingly survived 0-F during the 1985 freeze. However remember the condition of the tree prior to a freeze, and the length of time that the tree endures destructive temperatures are much more important than how low the temperature becomes. Yuzu, as the name implies is a native of Japan. When fully (note the word "fully") dormant the tree can endure 10-F for a period. It is used like a lemon, has just a few off flavors, but generally of good quality, with an edible peel. However, the fruit is very seedy. The Thomasville Citrangequat is an unusual tree, in that it has trifoliate, difoliate and uifoliate leaves all growing on the same tree. I have seen large Thomasville Citrangequat trees growing outdoors as far north as Virginia. The fruit has a lime flavor with no off flavors, with a fair to good quality. It becomes adequately sweet to eat out of hand around December or January. Thomasville Citrangequat is a cross between the Willits Citrange and a Nagami Kumquat, and is hardy to around 10-F. Thomasville Citrangequat is a very early maturing tree, may bloom as early as four years from seed. In Mass. all three of these trees will require protection during cold spells that are expected to last more than a few hours. I would advise that you only plant one tree at first, and grow/protect it for at least two winters before attempting to add additional varieties. Know that the hardy temperatures given applies to older mature trees. Young juvenile trees are much more susceptible to damage from adverse weather conditions. Freezes of 10-F or lower that last for 24 hours or longer are the real killers, even of many cold hardy varieties. There are many different conditions before and during a freeze that affect the actual hardiness of a tree at any given moment. Saying a tree is hardy to 0-F is useful, but only tells a piece of the account.

Hi

Thanks for all the helpful info. This year I am "growing" a calamandon outside. It is burried in an insulated cooler with heater cables and surrounded by buckkes of water that can be heated if needed. Last night it was 14 F and it was 48 degrees inside by "green house". I have serveral layers of clear plastic covering this and a blanket at night. If this is succesful then I hope to plant 3 trees in the spring.

Any comments are welcome, thanks again

Frank

how far north have people grown cold hardy citrus.........even with a lot of help/coverage

frank_zone5.5.. Your above posting is so good and well written. I invite you to make a posting in "Zone Us".. No need to get personal. Just tell us your zone and growing interest's