Author Topic: Marumi Kumquat, is it really the most cold hardy kumquat?  (Read 4174 times)

911311

  • Member
  • ***
  • Posts: 40
    • USA, Georgia, Atlanta, 7b
    • View Profile
Marumi Kumquat, is it really the most cold hardy kumquat?
« on: January 05, 2019, 11:21:45 AM »

  Some souce claimed that Marumi Kumquat can withstand 10F and start to lose leaves at 0F without injury. Is it a myth?

Citradia

  • Hero Member
  • *****
  • Posts: 958
    • USA/NC/Old Fort/6B
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #1 on: January 05, 2019, 10:44:13 PM »
A full-blooded kumquat is going to die deader than a door nail at 0 degrees F if not protected from the zero degrees F. My Thomasville citrangequat dies down to the ground at 7 degrees F. Of course it depends on how long your tree is exposed to temps below 32 degrees F. If itís below freezing for days at a time, you will see severe die back of your trees possibly loosing the entire tree. Even with wind breaks and wrapping the tree in cloth and burying it 6 feet deep in leaves, Iíve lost citranges 8 feet high to zero degrees during ďthe polar vortexes ď we had several years ago. Iíve seen 10 ft tall citranges cut in half or to the ground after a warm February followed by a 14 degree night in March after the trees started to put out just a centimeter of new growth, and these were trees protected in a high tunnel with water barrels next to each tree. Unprotected kumquat in zone 7 in the southeast USA gonna die.

poncirsguy

  • Hero Member
  • *****
  • Posts: 750
    • Cincinnati, Ohio, USA, 6a/6b
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #2 on: March 17, 2020, 09:40:29 PM »
It is more cold resistant to cold than nagami.  Grafted to poncirus trifoliata I'll give it 10F
« Last Edit: March 17, 2020, 10:04:56 PM by Millet »

SoCal2warm

  • Hero Member
  • *****
  • Posts: 1563
    • zone 10 and zone 8a
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #3 on: March 18, 2020, 07:55:13 PM »
I believe Meiwa is very nearly as hardy as Marumi, but I am by no means a kumquat expert.

Kumquats can only survive down to zone 8a, and that's only in the South, and they do not do well in the colder part of zone 8a, close to the border of zone 7.
I read of an experiment done close to Atlanta (zone 7b) where someone planted a kumquat, protecting it with a little frame covered by frost cloth, to see if it could survive. The winter killed it.

Is it the hardiest kumquat? Probably. Unless you count Ichangquat (kumquat x Ichang papeda), but that is a pretty hard one to get a hold of, and in addition the skin is said to have some moderate bitterness (although of course nothing like poncirus).

My small Ichangquat seedling appears to have survived outside through a winter in zone 8a, Olympia, WA, although the leaves do not look as good as the Yuzu.
Judging by how it has behaved, I would imagine a kumquat would really struggle up here, but I am not in the South.

There's also Sunquat (kumquat x Satsuma mandarin) but that is not any hardier than Meiwa.

SoCal2warm

  • Hero Member
  • *****
  • Posts: 1563
    • zone 10 and zone 8a
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #4 on: March 18, 2020, 08:07:43 PM »
  Some souce claimed that Marumi Kumquat can withstand 10F and start to lose leaves at 0F without injury. Is it a myth?
I highly doubt it. Yuzu is supposed to be hardy down to 10 F, and I am pretty certain a kumquat is not going to be as hardy as Yuzu.
(And Yuzu can definitely suffer some damage even above 10 F, so that number should not be taken to mean the plant will be just fine and healthy)

I was able to find this in my notes:

Nippon Orangequat 14 F or 10-16 F

These notes were derived from a compilation of a lot of research and anecdotal reports I read through.
I don't know if that helps any. I don't have any specific listings in my notes for Marumi kumquat.

a_Vivaldi

  • Member
  • ***
  • Posts: 112
    • Greenville, NC, Z8a
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #5 on: March 27, 2024, 02:51:10 PM »
The JC Raulston arboretum in Raleigh NC has a marumi kumquat that was planted in ground in 2011. In 2014 and 2015 Raleigh experienced single digit freezes. In 2017 that kumquat was measured as 4 ft tall, indicating that it had not frozen to the ground recently, and was certainly not dead. 2018 saw an even colder winter with a low in the lower single digits. The website seems to indicate the kumquat is still alive, so I'd hazard a guess that, at least in the South, and probably in part shade, marumi kumquat is hardy below 10 F.

They also have a Dunstan that was planted in 2009. I can attest that in 2021 that tree was not only alive and producing fruit, it was also a good 15-20 ft tall.

Mulberry0126

  • Member
  • ***
  • Posts: 82
    • North Carolina, Zone 7b/8a
    • View Profile
    • The Mulberries Edible Plant Nursery
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #6 on: March 28, 2024, 07:55:57 PM »
The JC Raulston arboretum in Raleigh NC has a marumi kumquat that was planted in ground in 2011. In 2014 and 2015 Raleigh experienced single digit freezes. In 2017 that kumquat was measured as 4 ft tall, indicating that it had not frozen to the ground recently, and was certainly not dead. 2018 saw an even colder winter with a low in the lower single digits. The website seems to indicate the kumquat is still alive, so I'd hazard a guess that, at least in the South, and probably in part shade, marumi kumquat is hardy below 10 F.

They also have a Dunstan that was planted in 2009. I can attest that in 2021 that tree was not only alive and producing fruit, it was also a good 15-20 ft tall.

If I may add, to the best of my knowledge it seems that the arboretum has misidentified most of their citrus with the exception of the Dunstan citrumelo. Their Citradia seems to be a Swingle citrumelo, their Ichang lemon is actually an Ichang papeda, and their Japanese kumquat may actually be Fortunella hindsii aka Hong Kong kumquat.
If these are in fact the correct varieties, it says a lot about the hardiness of Fortunella hindsii which may be greater than other kumquats. There is also the possibility they are planted in a good microclimate.

a_Vivaldi

  • Member
  • ***
  • Posts: 112
    • Greenville, NC, Z8a
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #7 on: March 28, 2024, 09:56:21 PM »
Good point about stuff being mislabeled. Their ichang lemon is definitely ichang papeda. Granted, they have it under the right species name so maybe they're using lemon as a generic for sour citrus.

I'm not entirely sure where their kumquat is. Judging by the map, it's in a section with a number of well established shade trees, which is helpful. I'm planning to visit again sometime this spring and I'll be keeping an eye out for it.

I wasn't aware Hong Kong kumquat was supposed to have much hardiness, Marumi is the I've read as being the most hardy. Whatever kind it is, they've got a very hardy kumquat, that's for sure.

Mulberry0126

  • Member
  • ***
  • Posts: 82
    • North Carolina, Zone 7b/8a
    • View Profile
    • The Mulberries Edible Plant Nursery
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #8 on: March 29, 2024, 06:01:43 PM »
If you visit again, I remember it being on a path between/behind the citrumelo trees. While I don't know for sure it is a Hong Kong kumquat, it looks very much like one, as opposed to any of the other kumquats. I germinated some seeds but they had weak root systems so I grafted them onto yuzu seedlings and now they are doing well. I've read they can be quite precocious so I'm eager to see them flower/fruit in the next year.

a_Vivaldi

  • Member
  • ***
  • Posts: 112
    • Greenville, NC, Z8a
    • View Profile
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #9 on: March 29, 2024, 07:45:34 PM »
Ok, did a little snooping around and I think you're right. I found more pictures of the one they have and it's definitely not Marumi. https://jcra.ncsu.edu/resources/photographs/results-common-name.php?search=round+kumquat

These guys seem to have the same thing, likely from JC Raulston itself, and they're calling it Hong Kong, though they get the ancestry wrong, and most of their citrus listings seem a bit off: https://nurcar.com/products/fortunella-hindsii?_pos=4&_sid=d8133fa2c&_ss=r

I wonder if the JC Raulston Hong Kong kumquat is the tetraploid wild form or the cultivated diploid variety. It'd be nice if it were the diploid. I've heard the same, even flowering after once year in some cases, which is pretty cool. I guess it helps that the fruit are so small.

Mulberry0126

  • Member
  • ***
  • Posts: 82
    • North Carolina, Zone 7b/8a
    • View Profile
    • The Mulberries Edible Plant Nursery
Re: Marumi Kumquat, is it really the most cold hardy kumquat?
« Reply #10 on: March 29, 2024, 09:08:28 PM »
They're very cool, and the small plants can likely support a single (equally small) fruit at least. They don't taste as good as other kumquats but the plant's hardiness is notable!
I have some "micro-grafted" Marumi kumquat plants that are probably still a couple years away from being able to support fruit, let alone testing their hardiness, but eventually I would like to experiment with them. I think either of these kumquats could make an interesting cross with a trifoliate hybrid.

 

SMF spam blocked by CleanTalk