Monday, January 13, 2014

Cold Hardiness Table



After a severe winter with a low of 6 F, -14.4 C, Eyeckr reported on the condition of his plants.[1]  This table is derived from his report.  Many thanks for this invaluable information.
































3/27/17:
After an extended warm period which saw some citrus setting out new growth, the temperature dropped to 21 F on 3/16/17.  Most citrus saw death of older leaves, in an erratic pattern.  In semi order of hardiness, from high to low.

LEAVES RETAINED:
MIC
Taichang Lemon
Clem-Yuz 2-2
Calamandarin
Nippon Orangequat
Morton
Ventura Lemandarin
Changsha
Thomasville Citrangequat

MIXED:
Juanita
Sunki Kat Mandarin
Ci Clem 10 Golden Lime
SRA 92

LEAVES LOST:
Kimbrough
Taiwanica
Shekwasha
Panzarella Orange
Clemnule
Sancitchang
Ujukitsu
Glen Citrangedin
Hanna Tokyo Pummelo

These results indicate that the plants which remained dormant longest are the most resistant to damage.

Varieties not included here are those that are deciduous or semi-deciduous

And finally,
Comparing Yuzu with Ichang papeda, Yuzu is hardier, Ichang had stem die back and is less vigorous.
These are just basic observations based on small numbers of plants and limited cultural conditions.  Other years/conditions might yield different results.


Extensive list of cold tolerant citrus  Poncirus  data is wrong

20 comments:

  1. HI there,
    Just noticed your blog, and as a citrus enthusiast from a marginal citrus growing area So.Ga./No.Fl., I was interested. Where are you located? Are you observations based on personal experience or reading?
    If you can't send commentators an email, I will try posting again with my address, although I'm wary to make it in a public post.
    Thanks,
    ES

    ReplyDelete
    Replies
    1. Nearly all the ratings are based on published material. Usually every variety listed has one or more links to the source material for temperature. I am near Anderson SC. I may have added material from personal correspondence or observation. The temperature here dropped to 9 degrees F. this past winter.

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  2. Hi, just found this page, have you ever heard of a cold hardy citrus called "from Russia with love"? trying to locate.
    Thanks

    ReplyDelete
  3. Well if you are trying to locate that then you must have a huge selection of plants.

    Only information I have about that variety is here.
    http://www.scribd.com/doc/138537543/Hardy-Citrus-of-Texas

    It was a plant Dr. Brown named because identification was uncertain.

    Hope you will share information you have about cold hardy varieties.


    ReplyDelete
  4. Where can i get these seeds? I want to buy them. contact me, please.
    US 852, Juanita, Changsha, Ten-Degree Tangerine, US 119, Hana Tokyo Pommelo,
    keraji mandarin, Tiwanica lemon(Bergamot orange)

    ReplyDelete
  5. Where are you located? Most of these plants are available in Europe and US. Sources are mentioned elsewhere in on the blog. Seed are harder to come by. I bought Keraji on Ebay twice and the seed were dead. Citrus seed cannot be allowed to dry out.

    ReplyDelete
  6. Dead as a doornail Marumi kumquat.
    Was that on its own roots or grafted to ?. I have been thinking of an in ground Marumi in Cincinnati, OH
    Steve

    ReplyDelete
    Replies
    1. Steve,
      This information came from Eyeckr. He usually had high grafted on Poncirus, but I do not know for sure. There is a big difference between surviving one night of extremely cold weather vs. prolonged cold weather. Unless you are prepared to cover your tree in the coldest weather it will not survive. A week of steady cold weather with a low around 8 F killed many of my potted citrus this past winter. A tree that does not lose it's leaves will become desiccated during extended freezing weather.

      Delete
  7. Ten degree tangerine and yuzu have both died here in Portland, OR at about 15 degrees.

    ReplyDelete
  8. I read a few post of Eyeckr on tropical fruit forum, not reliable. His or her report was based on a simple experiment with a very limit number of samples. We need a formal report from a well know research institution or University.

    ReplyDelete
  9. Good idea. How would you fix the situation?

    ReplyDelete
  10. I'm zone 7b (raleigh nc), and my yuzu has handled 10f fine; however, we don't stay at 10f very long. Its also planted on the south side of a brick home for some protection from nothern winds. Yuzu is thriving the most for me so far. This is the 2nd year it has fruited. A lot has to do with your microclimate, and I wouldn't be surprised if soil makes a difference as well.
    I have a bunch of other varieties in the ground (some flowering)/fruiting, but they are still too small in size to really evaluate. Prague has sailed through winters at less than 2ft tall with no damage; although, for me it seems to be deciduous.

    ReplyDelete
    Replies
    1. Hello Josue. Thank you very much for your comment, you give hope.

      Could you explain more about the climate you are in? The temperature of 10F, is the minimum temperature? mean in the winter? how cold are you?

      Thanks a lot

      Delete
  11. Thanks for your report, please continue to report your results. The poncirus layer in Prague would make it deciduous.

    ReplyDelete
  12. Which ones of those cold hardy to -15C (5F) ha fragrant blossoms? Anyone with the Orange Tree fragrance?

    ReplyDelete
    Replies
    1. I will check next year. Poncirus is usually scentless, hybrids should have some fragrance, but less than a standard orange tree.

      There is a plant called Wintergreen, Gaultheria procumbens with flowers that smell like oranges. I knew Wintergreen fragrance before orange fragrance, so oranges blossoms always smell like Wintergreen flowers to me and not the other way around. The fruits have a refreshing taste to some people. It is a ground cover and very hardy.

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    2. Thank you for the advise but Wintergreen seems intolerant of alkaline soil which I have. I found out Morton is the only one of the cold hardiest with some scent.

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    3. Add sulfur to the soil to acidify it, also add pine needles and oak leaves. Blueberries are grown that way in more alkaline soil.

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  13. Great Blog!

    Please do keep up the good work. This is the best resource I have found so far on cold hardy citrus.

    I am currently aging some "Improved Meyer Lemons" and two Satsuma (one is Owari) in containers. The mandarins are grafted onto trifoliate. They will be going into the ground on the South side of my home in a super protected spot next Spring.

    I am located on the border of 7A/8B in Chesapeake, VA.

    ReplyDelete
    Replies
    1. Thank you very much. Google has made it very difficult to modify this blog without using coding. I will be transferring to some other site that is easier to use.

      Delete