The Tropical Fruit Forum

Citrus => Cold Hardy Citrus => Topic started by: Pandan on February 10, 2022, 06:13:35 PM

Title: Cold hardy lemons
Post by: Pandan on February 10, 2022, 06:13:35 PM
Anyone ever bred a cold hardy lemon or close substitute?
What would be some good cultivars for starting a cold hardy lemon - for example hamlin is a hardier orange that also ripens before frost so what would be its lemon equivalent.

UGA has the grand frost lemon, which has an ichang lemon base.

I remember I liked the ichang lemon but from what I remember it it wasn't as sour as a standard lemon. Yuzu just didn't have enough flavor for me. Its been some time since I tried either one directly so let me know if your experience differs.
Title: Re: Cold hardy lemons
Post by: Citradia on February 10, 2022, 08:12:39 PM
If Ichang lemon isn’t sour enough, try citremon. It will be more cold hardy too. I like swingle citrumelo as a lemon substitute too.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on February 12, 2022, 01:07:06 AM
What would be some good cultivars for starting a cold hardy lemon
Maybe if someone bred citron with yuzu and then crossed that with ichang lemon.
Title: Re: Cold hardy lemons
Post by: manfromyard on February 12, 2022, 10:17:58 AM
I've always though nanshodaidai/taiwanica with an ichang papeda would been a great candidate.
Lemons were supposedy a sour orange with a citron, so a hardy sour orange with papeda seems like a similar cross for a cold hardy lemonlike fruit..
Title: Re: Cold hardy lemons
Post by: Pandan on February 13, 2022, 12:19:20 AM
I've been doing some light research on the citrus variety site:

Khasi papedas may be another hardy lemon-y base worth considering.
Kabosu is similar to zaidaidai and is related to yuzu but more acidic.

true lemons:
A "true" lemon that ripens in fall is the interdonato -
https://citrusvariety.ucr.edu/citrus/interdonato.html

Messinna - "The pulp is very juicy and acidic." early harvest in autumn, poor everbearer https://citrusvariety.ucr.edu/citrus/messina_4121.html

The arancio is mentioned as being hardy & compact but ripening date isn't mentioned & the quality isn't prime
https://citrusvariety.ucr.edu/citrus/arancino.html

I don't think I've tasted any of these so far however.
Title: Re: Cold hardy lemons
Post by: Pandan on February 13, 2022, 01:00:44 AM
This is one is a stretch lol: heres also something on the "gul gul" or gal-gal psuedolimon (Citrus pseudolimon Tanaka) from India https://citrusvariety.ucr.edu/citrus/CRC4235.html
The short desc itself doesn't mention hardiness but assuming its a native gal-gal (aka a "hill lemon") then it'd be from the colder northern regions of india, so possibly hardy

https://citrusvariety.ucr.edu/citrus/soghi.html - another selection from the soghi area mentioned, could just be a normal lime seedling
Title: Re: Cold hardy lemons
Post by: poncirsguy on February 13, 2022, 09:40:15 AM
Harvey lemon is able to go below 10F if grafted to Poncirus Trifoliata or Flying dragon.  How cold are you looking to develop.  Lemons take 9 months from small flower bud to ripe fruit.  Will it have time after last frost to start flower buds and be ripe to clear first fall frost and still be in zone 8 (10F)
Title: Re: Cold hardy lemons
Post by: manfromyard on February 13, 2022, 01:46:30 PM
I've been doing some light research on the citrus variety site:

Khasi papedas may be another hardy lemon-y base worth considering.
Kabosu is similar to zaidaidai and is related to yuzu but more acidic.

true lemons:
A "true" lemon that ripens in fall is the interdonato -
https://citrusvariety.ucr.edu/citrus/interdonato.html

Messinna - "The pulp is very juicy and acidic." early harvest in autumn, poor everbearer https://citrusvariety.ucr.edu/citrus/messina_4121.html

The arancio is mentioned as being hardy & compact but ripening date isn't mentioned & the quality isn't prime
https://citrusvariety.ucr.edu/citrus/arancino.html

I don't think I've tasted any of these so far however.

Kabosu is consistently reviewed as not very acidic, almost to the point of being insipid. UCR mentions the la hck of acidity versus Yuzu and Sudachi. And people who taste them like weird fruit explorer and a few others say the same. Might want to leave that one alone..

And Hardy for a mainstream lemon is relative. A Lisbon lemon is considered hardy out west because they're comparing it to Eureka..
Title: Re: Cold hardy lemons
Post by: SoCal2warm on February 13, 2022, 09:01:25 PM
The true lemon flavor comes from the original citrus species citron. But I think a little bit of the fragrance of lemon also comes from pomelo as well. The juiciness of lemon does not come (or barely comes) from citron, but rather pomelo and/or mandarin. The proportion of mandarin cannot be too high otherwise the flavor will be too "orange" rather than distinct lemon.

Ichang papeda has a flavor that is half similar to citron, it does not have the "orange" component. (Actually I would describe it as half citron and half Kaffir lime) But the flavor of Ichang papeda is still a little bit inferior to citron, I would say. So to develop a high quality hardy lemon, I think perhaps citron should be bred into there. Unfortunately citron has very little hardiness.

I have had the opportunity to taste citron, both Ichang papeda and Yuzu picked fresh off the tree. And of course I have tasted pomelo. (I have not actually had the opportunity to taste Ichang lemon though)

You could of course try crossing a regular lemon with something else, but my thought was that if you began with a citron rather than a lemon, the resulting hybrid would retain a more distinctive citron/lemon flavor, since the citron ancestry has not been diluted as much.

A direct cross between a lemon and anything else that is really lemon-like, probably is not going to be cold tolerant enough. I think at least two subsequent hybridizations will be required.
Title: Re: Cold hardy lemons
Post by: Pandan on February 14, 2022, 01:10:11 PM
Thank you for the contributions so far everyone!
I posted this as a general curiousity and its turning into a nice brainstorm.


Kabosu is consistently reviewed as not very acidic, almost to the point of being insipid. [...]
And Hardy for a mainstream lemon is relative. A Lisbon lemon is considered hardy out west because they're comparing it to Eureka..
Good point on the relativity, that’s something to take in mind.  Those darn californians and their fair weather lol
Thank you for informing me about kabosu.

Harvey lemon is able to go below 10F if grafted to Poncirus Trifoliata or Flying dragon.  How cold are you looking to develop.  Lemons take 9 months from small flower bud to ripe fruit.  Will it have time after last frost to start flower buds and be ripe to clear first fall frost and still be in zone 8 (10F)
Good question :x
with 190 frost free days in a year for us zone 8'ers we'd be cutting it so how could I work around that
Could this also be improved for in a hybrid with fall-bearing cold hardy citrus? Maybe that ripening time is something that could be overcome by hardy citrus genetics.
Would light everbearing be a good trait in a hardy lemon for fruit set?

I googled it and saw thee 9 month estimate as well but I guess there are some lemons that mature faster
later I saw that according to FL extention lemons can ripen from "4 to 12 months depending"
https://edis.ifas.ufl.edu/publication/hs402

Here is a link I found that mentions other cold-tolerant cultivars - like manfromyard said, this “hardiness” is probably relative.
It mentions Genoa, Harvey as you said and Lisbon again.

Villafranca, feminello ovale, Interdonato and rosenberger were mentioned with some praise or interesting characteristics.
https://hort.purdue.edu/newcrop/morton/lemon.html

The true lemon flavor comes from the original citrus species citron. But I think a little bit of the fragrance of lemon also comes from pomelo as well. [...]
Ichang papeda has a flavor that is half similar to citron, it does not have the "orange" component. [..] Unfortunately citron has very little hardiness.
[..]
You could of course try crossing a regular lemon with something else, but my thought was that if you began with a citron rather than a lemon, the resulting hybrid would retain a more distinctive citron/lemon flavor, since the citron ancestry has not been diluted as much
Yep, that piquant flavor alongside true sourness is what's also missing from the lemon-ish substitutes.
Quote
A direct cross between a lemon and anything else that is really lemon-like, probably is not going to be cold tolerant enough. I think at least two subsequent hybridizations will be required.
Like with citranges I’m sure I’d have duds and dud-ettes before hitting something even slightly in the ballpark. What I’m wondering is how adversely would pure citron affect hardiness in comparison to lemons?  How do citrons and lemons generally compare to each other in hardiness? I’m not even sure which citron would be a good start as I know less about that species.

I thought of this but didn't mention it earlier but I wonder about rough lemons (Jambiri Citrus) as breedstock. They’re a mix of citrons and mandarins.
The descriptions on those on UCR are mostly copy/pasted which makes it hard to tell if any of them have any potential. If they ARE all as cold-sensitive as the citron parent I’d assume sensitivity runs over any mandarin’s hardier genes.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on February 14, 2022, 05:37:49 PM
Kabosu is consistently reviewed as not very acidic, almost to the point of being insipid. UCR mentions the lack of acidity versus Yuzu and Sudachi. And people who taste them like weird fruit explorer and a few others say the same. Might want to leave that one alone..
You do realize that in Japan Sudachi and Kabosu are traditionally picked green, while they are still not all the way ripe?
Otherwise they lack sourness and become insipid.

Kabosu is a very specific regional citrus and was traditionally only found in one province in Japan, so it was never really widespread in that country.

I have actually tasted an all the way ripe Kabosu picked from the tree, and what it is basically it makes a good marmalade orange, although mild in flavor and not very sour (although still maybe a little more sour than a sweet orange).

The best time to pick Kabosu, assuming you want to use it like a lemon, is while it is still green but turning yellow. If it is already turning orange it is a little too late.
Title: Re: Cold hardy lemons
Post by: manfromyard on February 14, 2022, 09:25:19 PM
I do realize that Sudachi and Kabosu are both picked green or right at color break.
It's an intrinsic quality. If they're all picked at the same stage of green, Kabosu will still be less sour than  either Sudachi or Yuzu.
So if Sour is what you really want, you're better off with Yuzu or Sudachi
You can watch any of a number of videos actually showing reactions, or read UCR's notes below:

"  Kabosu fruit was also formally evaluated in September and October from 2003 through 2007 at Riverside, Calif. Slightly larger than Yuzu, the average fruit size has a mean width of 5.3 cm (2.1 inches) and a height of 5.2 cm (2.0 inches), giving an average height-to-width aspect ratio of 0.98 and a more rounded shaped. Kabosu has a mean weight per fruit of 71.2 grams (2.51 ounces). Color break for Kabosu occurs between the first and third week of September. The rind texture is slightly pebbly with a mean thickness of 4.2 mm (.17 inches). The number of seeds per fruit averages 17.2, higher than Sudachi, but lower than Yuzu. The mean juice weight is 20.2 grams (0.71 ounces) and the average juice content is 28.2%, slightly higher than Yuzu, but lower than Sudachi. The juice weight and juice content increased during the sampling dates. The internal flesh color of Kabosu in the green stage ranges from light-yellow to dark-yellow. Kabosu tends to be the least acidic of the three acid types with an average of 3.2% citric acid."

https://citrusvariety.ucr.edu/citrus/kabosu1.html

Title: Re: Cold hardy lemons
Post by: CarolinaZone on February 27, 2022, 03:10:01 PM
Have you considered a Harvey Lemon?
Title: Re: Cold hardy lemons
Post by: Pandan on February 28, 2022, 05:46:26 AM
Have you considered a Harvey Lemon?
I have and now I'm considering trying my little newbie hands at breeding a sour-er, more flavorful hardy lemon

perhaps harvey x this citremon one day https://citrusvariety.ucr.edu/citrus/citremon_1449.html

meyer x citremon may be another mix
Title: Re: Cold hardy lemons
Post by: poncirsguy on February 28, 2022, 09:11:00 AM
I am confused with why anyone would want to breed a lemon that is even more inedible than the standard eureka lemon.  What would it be used for.  I guess I could clean my car battery posts with it.
Title: Re: Cold hardy lemons
Post by: Oolie on February 28, 2022, 05:42:41 PM
I am confused with why anyone would want to breed a lemon that is even more inedible than the standard eureka lemon.  What would it be used for.  I guess I could clean my car battery posts with it.

Some people enjoy sour tastes.

If you could create a limequat, a lemonquat should be possible maybe possible.

I'm not sure, but I thought calamansi was at least somewhat cold hardy, though probably not to the degree of a mandarin or kumquat.
Title: Re: Cold hardy lemons
Post by: Pandan on February 28, 2022, 07:57:06 PM
I am confused with why anyone would want to breed a lemon that is even more inedible than the standard eureka lemon.  What would it be used for.  I guess I could clean my car battery posts with it.
Haha, its the cold hardy part with lemon flavor (including sourness) thats important. The majority of cold hardy lemon subs aren't actually that sour or have too different flavor profiles from lemons. Going too sour is why I mentioned a meyer backcross with citremon as meyer is hardier and also sweeter/less acidic to help balance things.

The battery cleaner citrus is another later project ofc  ;D
Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 01, 2022, 05:48:06 PM
What I’m wondering is how adversely would pure citron affect hardiness in comparison to lemons?  How do citrons and lemons generally compare to each other in hardiness? I’m not even sure which citron would be a good start as I know less about that species.
This is the way I would think of it. Lemons are only more hardy because sour orange has been introduced into the citron ancestry. Sour orange is moderately hardy, mainly I think because it is so vigorous growing and can easily recover so fast. Chinotto sour orange is known to be able to survive down to 18 F (although I have tasted them and they are rather bitter, not ideal for any culinary use, although it is not completely impossible to be able to "snack" on one small fruit. other sour oranges are better in quality, such as the traditional marmalade orange).

So do we really want sour orange introduced into our lemon line to add more hardiness. I personally do not think that is ideal. The trade-off for increase in hardiness (which is not great) might not be worth the more orange flavor. The only difference is that citron can only grow in climate zone 10, does not always do well in 10a, whereas a normal lemon can easily grow in 10a and often can be grown in 9b. It might only very much struggle in 9a. (I am sure many more expert citrus growers might disagree with me)
Of course you could easily begin with a regular lemon (such as Lisbon) if that is easier for you. I was just suggesting that theoretically, a citron might be more optimal to begin with. Lisbon still has great flavor and no one will argue it is not "lemon" enough in flavor.

Meyer lemon is believed to have resulted from a more direct cross between citron and mandarin, and is more like equal parts of both, so it is less lemon-like in flavor. A cross already exists between Meyer lemon and trifoliate. It is called citremon.

I thought of this but didn't mention it earlier but I wonder about rough lemons (Jambiri Citrus) as breedstock. They’re a mix of citrons and mandarins.
I have tasted fruit from a big tree that I believe was a rough lemon rootstock, and unfortunately, while they are pleasantly fragrant, they are very bitter and completely inedible, not to mention being rather dry on the inside.
I actually tested seedlings grown from seeds of this fruit, and it was not able to survive a winter in the PNW climate zone 8, whereas Yuzu seedlings did survive.
Title: Re: Cold hardy lemons
Post by: Pandan on March 02, 2022, 02:27:16 AM
What I’m wondering is how adversely would pure citron affect hardiness in comparison to lemons?  How do citrons and lemons generally compare to each other in hardiness? I’m not even sure which citron would be a good start as I know less about that species.
This is the way I would think of it. Lemons are only more hardy because sour orange has been introduced into the citron ancestry. Sour orange is moderately hardy, mainly I think because it is so vigorous growing and can easily recover so fast. Chinotto sour orange is known to be able to survive down to 18 F (although I have tasted them and they are rather bitter, not ideal for any culinary use, although it is not completely impossible to be able to "snack" on one small fruit. other sour oranges are better in quality, such as the traditional marmalade orange).

So do we really want sour orange introduced into our lemon line to add more hardiness. I personally do not think that is ideal. The trade-off for increase in hardiness (which is not great) might not be worth the more orange flavor. The only difference is that citron can only grow in climate zone 10, does not always do well in 10a, whereas a normal lemon can easily grow in 10a and often can be grown in 9b. It might only very much struggle in 9a. (I am sure many more expert citrus growers might disagree with me)
Of course you could easily begin with a regular lemon (such as Lisbon) if that is easier for you. I was just suggesting that theoretically, a citron might be more optimal to begin with. Lisbon still has great flavor and no one will argue it is not "lemon" enough in flavor.

Meyer lemon is believed to have resulted from a more direct cross between citron and mandarin, and is more like equal parts of both, so it is less lemon-like in flavor. A cross already exists between Meyer lemon and trifoliate. It is called citremon.

I really appreciate your input! I'd love to make a lot of crosses but to save resources I can't re-invent the wheel with lotsa basal crossing (it might be fun but I currently don't have the space or cash LOL)
----
I'm choosing 4 cultivars (harvey/citremon/Ichang Lemon/Meyer) because they all meet my criteria of hardiness, ripening time and flavor to different extents. I think a citremon back cross (citremon back to meyer or harvey) or ichang lemon x harvey would be strong starting grounds. IL x Citremon is another possibility. I like my chances.

Perhaps there are better flavored lemons but I know I can get those 2 easily and I've seen their hardiness attested compared to other cultivars.

A nursery in my state sells a lemon cocktail tree which is great, I need to find the citremon and IL now. They're both currently out of stock everywhere it seems but its also still early for tree nurseries ig.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 02, 2022, 04:45:36 AM
I like swingle citrumelo as a lemon substitute too.
Many people say Dunstan citrumelo is not too far from the feel of a lemon, and at its best is almost edible without too much trifoliate taste.
Well, more like a sour grapefruit of course, but it might make a good starting point. Maybe cross it with a normal lemon. I doubt that resulting hybrid would have cold tolerance, so you'd probably have to take a large number of seeds from the resulting fruit of that new hybrid, and see if any of the subsequent offspring have cold tolerance. It would probably take one more generation to bring out all those recessive genes.

I think that may be why developing hardy citrus has not been so easy and many have not succeeded.
If you just take trifoliate and cross it with another normal citrus, and then take that and cross it once more with another normal citrus that has no cold tolerance, very little of the original trifoliate cold tolerance is going to manifest, even under the best chances. I think you would have to do one more additional self-cross after that, to have any chance of strengthening back the cold tolerance genes.

It's clearly obvious that most of the genes for cold tolerance do not appear to be dominant genes.
Title: Re: Cold hardy lemons
Post by: mikkel on March 02, 2022, 06:35:50 AM
this is a rather simple idea of heredity and genetics in general.
there are some examples of cold-hardy F1 hybrids with almost edible fruits. there are also some candidates from the F2 generation, you just have to read and observe carefully.
it is true that a simple cross between poncirus and citrus will not produce a predictable result, no matter how much you think about it beforehand, it always depends on the number of seedlings, the greater the number of seedlings the greater the probability of finding the desired gene combination, it is much more about probabilities and not only about recessive and dominant.

Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 02, 2022, 06:44:38 AM
it is true that a simple cross between poncirus and citrus will not produce a predictable result, no matter how much you think about it beforehand, it always depends on the number of seedlings, the greater the number of seedlings the greater the probability of finding the desired gene combination, it is much more about probabilities and not only about recessive and dominant.
I just do not think the desired gene combination is going to be able to be achieved in one hybridization. It will take two.

Several seedlings will have to be grown, and then subsequently numerous seeds from each of those seedlings will have to be grown.

Many of the seeds may turn out to be nucellar (genetic clones of the fruit parent they came from) so that will turn out to be a waste.

If it were so easy as just make one hybridization and growing many seeds, I am sure more progress would have been made by now.


The first thing is you have to breed out the bad qualities, while retaining some of the genes for the good qualities, and then you have to breed back to try to more fully get the genes for the good qualities.
Title: Re: Cold hardy lemons
Post by: mikkel on March 02, 2022, 09:00:08 AM
always preaching... I'm sorry to have to say this so directly, but sometimes I wonder if you even read what others write? and also think about it....
Title: Re: Cold hardy lemons
Post by: kumin on March 02, 2022, 10:08:08 AM
Selection within mass populations of F² and higher generations containing both Poncirus and Citrus genetics on both parents' sides should allow the opportunity for a very small number of progeny to restore the homogeneous state of desirable genes from Poncirus, as well as Citrus, in regards to cold hardiness and palatability.
Linkages obviously complicate and delay the process. A number of selections from the F² trial I undertook several years ago approach Poncirus cold hardiness, while also exhibiting a few Citrus characteristics. By further selection amongst the F³ generation, utilizing the hardy F² generation as parents, the percentage of cold hardy survivors should increase substantially. At this point, selection could be made for edibility.
Nucellar embryony is a considerable hindrance to the process and the more quickly completely zygotic breeding lines can be established, the better.

The discovery of an initial zygotic selection with the full hardiness of Poncirus combined with even mediocre taste can accelerate the process from a breeding perspective, if not from a widely accepted cultivar introduction.
Title: Re: Cold hardy lemons
Post by: Pandan on March 02, 2022, 10:19:56 AM
Keep it cordial fellas!
You're basically both agreeing with each other and i'm agreeing with you both.

For brevity I didn't say "and make selections to which I'd backcross with" but that's definitely the plan if necessary.
Make crosses (get as many seeds as possible) -> let winter do its thing -> cross what survives and meets or comes close goals and repeat until satisfied.  I think good stock would leave me less work to do even in the F1 and large numbers / diversity only increase my chances.

Another pro is that the 4 cultivars I'm thinking of I know 1 (meyer) is mono embryonic, I safely believe Ichang Lemon is mono as well, citremon may or may not be true to seed not sure but it could be a pollen parent. Harvey I'm not sure.

The space issue comes up again but lets ignore that for now  ;D

Earlier I said "starting grounds" because I know it may not be a single cross (or maybe I'll get lucky) and even if I did get something good from some F1 I'd probably continue for a higher goal (I.E. a true deciduous lemon beyond a hardy evergreen). I have been thinking about this awhile so maybe I should just dump my thoughts into a post.
Title: Re: Cold hardy lemons
Post by: Pandan on March 02, 2022, 10:44:45 AM
Selection within mass populations of F² and higher generations containing both Poncirus and Citrus genetics on both parents' sides should allow the opportunity for a very small number of progeny to restore the homogeneous state of desirable genes from Poncirus, as well as Citrus, in regards to cold hardiness and palatability.
Linkages obviously complicate and delay the process. A number of selections from the F² trial I undertook several years ago approach Poncirus cold hardiness, while also exhibiting a few Citrus characteristics. By further selection amongst the F³ generation, utilizing the hardy F² generation as parents, the percentage of cold hardy survivors should increase substantially. At this point, selection could be made for edibility.
Nucellar embryony is a considerable hindrance to the process and the more quickly completely zygotic breeding lines can be established, the better.

The discovery of an initial zygotic selection with the full hardiness of Poncirus combined with even mediocre taste can accelerate the process from a breeding perspective, if not from a widely accepted cultivar introduction.
I'm happy to see you commenting, your hardiness trial posts are a major inspiration for this. Before I write this down and get laughed at please remember I'm an idealistic novice:

Actually when I first thought of this I imagined a Kumin style mass trial for various lemon-esque hardy evergreens using rootstock seeds from Lyn Citrus: https://lyncitrusseed.com/rootstock-seed/ they have yuzu, volkamericana. Do a trial in a zone 7 area and then have the next generation of those tested in a colder zone.
The cons of this came fast: I'm in a zone 8 / zone 7 cusp area so the selection pressure may not be enough to produce something interesting and I have limited access to land. One day hopefully.

Back to the new plan I think this is a goal that could be accomplished on a smaller scale than citranges IF the goal is "zone 8 improved lemon hybrid" - going colder is another option to be taken from there too with poncirus heritage.
Title: Re: Cold hardy lemons
Post by: maesy on March 02, 2022, 02:19:31 PM
Thomasville citrangequat would also be a good substitute for a lemon.
Very juicy, tasty and when fully ripe sweet with eatable rind almost like a kumquat.
And very frost hardy as too.
Title: Re: Cold hardy lemons
Post by: mikkel on March 02, 2022, 04:30:58 PM
I have been thinking about this awhile so maybe I should just dump my thoughts into a post.

Yes, it would be nice to hear!
Title: Re: Cold hardy lemons
Post by: Pandan on March 04, 2022, 04:16:33 AM
Ok so this is an almost stream-of-conscious 2 part write up with some notes and redundancy:

1. The mass trial method - Inspired by Kumin's posts
I was thinking buying a whole sale amount of yuzu, taiwanica, volkamer etc  for a large plant out and taking seeds from survivors grex style etc

Note: this would have been less about lemons and a longer term project looking to push various zone 8 citrus (yuzu in particular) hardiness further using mass planting and natural selection. These hardier prodigies' progeny could be used for other breeding goals.
http://thecitrusguy.blogspot.com/2010/08/to-seed-or-not-to-seed.html?m=1

Considerations:
●Zones: i feel a trial would need to take place in a zone 7 (a or b) area - this would push towards the hardier genetics without tipping to the wipe out point. Ofc one could go straight to a colder zone areas and trial as they please.
My plan would be: mass trial -> breed survivors -> send seeds to colder place -> repeat

My area isn't particularly a good "make or break" zone for hardy citrus, I imagine they'd find it too comfortable. I may also be over/underestimating how hardy these are (most nursery stay zone 8 so thats what I’m repeating, I haven’t looked into papers or anecdotes)

●Seeds: For several promising hardy citrus there is simply no mass producer of the seeds, finding stock for ichang lemon, kumquats,   - you'd need to be your own supplier.
Maybe this isnt the biggest issue esp for people with their own orchards but it is a consideration because it adds time to getting seeds. Many users on here know the feeling of losing a single precious cross,. Citranges have an advantage in this area as their use as industry rootstock leads to higher availability

●species prioritization - I can say I wouldn’t want too many if any poncirus hybrids in this, (almost “hardy” citrus is the focus as poncirus is proven) but should a mass planting include mixed plants?  I’d prefer a mixed grow but that brings its own issues if one’s concerned about parentage etc. Perhaps a line should be focused on a time?

●Time - this would take years to bear fruit from seed but that’s a given

▪︎On a personal level I simply don't have the space required.
Title: Re: Cold hardy lemons
Post by: Pandan on March 04, 2022, 04:25:28 AM
part 2: this is extra messy
2.) hybridization   - Using already available cultivars to breed something new

In order to do this I needed information on what to select for. I used Hamlin orange as an approximate example so people know what I meant in the first post.

Basic criteria:
○A history of taking below freezing temperatures
▪︎(for actual lemons close(r) to freezing, at least hardier than standard)
○Ripens before dec, preferably oct-nov
○Lemon flavor / sour

points made by members:
>Frost destroys fruit so we'd need something that sets before frost.
> as @ pointed out lemons can take 9 months ??
> "cold hardy" is relative for the 2 or 3 big, warm citrus states (CA, FL & TX)


(From here you can go through the thread and see my thought process as you all helped me eliminate or reconsider many choices.)

Project goals:
An improved, hardy lemon tasting citrus - must be able to survive zone 8a to zone 7 no protection and fruit before frost.

Project notes: for zone 8 there is decent hardy citrus besides mandarins. They aren't very flavorful, not sour and don't have lemon flavor notes.

Further projects:
Using poncirus crosses to get a deciduous lemon - this would take generations

From here I decided I'd try to use Harvey, Meyer, Citremon and Ichang lemon (while keeping an open mind) and my initial planned crosses:
Meyer x citremon
Meyer x harvey
IL x harvey
IL x citremon

Knowing meyer & IL are monoembeyonic would save a lot of concerns about cloning. The F1s would be bred to each other.


Lemon choice alternatives:
Sunquat(?)
Genoa
Interdonato (? fall bearer + greater citron heritage)
Bearss lime (NOT hardy but monoembryonic, low seeded & crops in Oct, perhaps a start for a hardy lime spin off)

Hardy citrus* of interest :
Ichang Papeda - CRC 3931
Khasi Papeda - CRC 3052
Citrus Hongheensis - CRC 3797

Hyuganatsu (bland yuzu pomelo hybrid I havent tried, but its heritage is similar to Ichang lemon which I like and supposedly its not too seedy)

Citrangequats? (Could dilute lemon flavors too much)
note: Ive heard ichang papeda x poncirus crosses lend to less bitter hybrids (n1tr1 is supposedly one).
But ichang lemon isnt papeda - a forum expert (ilya) said its yuzu x pomelo. Would this mix challenge any off poncirus flavors? Does it matter? No but still something to look into anyways.

* this was just a quick list

Smaller things thatd be nice:
•Bright yellow rind & flesh - hardy varieties tend to be so dull
•A flavorful rind
•Shape, Id prefer that pinched end oval shape but beggars aren't choosers
•Smooth rind
°"Juicyness"? Most of this can come later


-

IF any of you know the gene(s) related to hardiness and flavor you can use program to
https://colab.research.google.com/drive/1ShEUyKkSrhGRADCw9ertgjF5OrfNTjSW?usp=sharing
•Details on how to run (need google account sadly) and creator here: https://www.facebook.com/groups/PlantBreedingForPermaculture/posts/1989725684524388/

Other ideas; I want to reach out to an org that helps organize collaborative plant breeding

I don’t know all the agricultural terms and please excuse any presumptive-ness as that’s not my intent.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 04, 2022, 07:03:09 AM
I do have a small Yuzu tree growing in the same yard space as a large Eureka lemon in climate zone 10. I suppose I could try to do a cross pollination and share some seeds. I highly doubt the offspring could grow in zone 8 though.
Title: Re: Cold hardy lemons
Post by: Walt on March 04, 2022, 11:07:04 AM
"Other ideas; I want to reach out to an org that helps organize collaborative plant breeding"

Experimental Farm Network.  Google it.  It has been operating for several years. 
It
Title: Re: Cold hardy lemons
Post by: Pandan on March 04, 2022, 01:41:02 PM
"Other ideas; I want to reach out to an org that helps organize collaborative plant breeding"

Experimental Farm Network.  Google it.  It has been operating for several years. 
It
I know, thats the exact one I was thinking of.

I do have a small Yuzu tree growing in the same yard space as a large Eureka lemon in climate zone 10. I suppose I could try to do a cross pollination and share some seeds. I highly doubt the offspring could grow in zone 8 though.
Never know unless you try. A lot of this stuff would be up to luck and the numbers game with educated guesses helping out.
Title: Re: Cold hardy lemons
Post by: mikkel on March 04, 2022, 06:15:01 PM

In my garden, seedlings of Khasi Papeda are not as hardy as those of Ichang Papeda. I P loses younger leaves and summer shoots freeze back. But Khasi Papeda dies above ground every winter, but came back every time. But it survives with difficulty and has little growth.I still have one plant from originally over a hundred.
Title: Re: Cold hardy lemons
Post by: Pandan on March 05, 2022, 05:01:12 AM

In my garden, seedlings of Khasi Papeda are not as hardy as those of Ichang Papeda. I P loses younger leaves and summer shoots freeze back. But Khasi Papeda dies above ground every winter, but came back every time. But it survives with difficulty and has little growth.I still have one plant from originally over a hundred.
You're the only person I've seen mention growing these I think.
I'm disappointed to hear this especially that even the sole survivor isn't that vigorous.  :-[

I lightly looked into Indian citrus varieties from the mountainous region of the country (Assam etc) but their hardiness may be an example of that "hardy for warm areas" point brought up earlier.

===
posting some more references-
Here's a good forum post a few years old that talks about how much hardiness can vary for many reasons:
https://tropicalfruitforum.com/index.php?topic=24371.0
Title: Re: Cold hardy lemons
Post by: Pandan on March 14, 2022, 03:18:56 PM
Has anyone grown or tried hanayu?

https://citrusvariety.ucr.edu/citrus/CRC3469.html
EMN, 11/23/1988: A small, yellow, seedy fruit; very sour. Somewhat lemon-like in flavor.
It doesn't say anything about hardiness but I assume its hardy like its kabosu n such.

but also interestingly I found a paper that mentions hanayu crosses (along with yuzu & kabosu) having precocious flowering.
https://catalog.lib.kyushu-u.ac.jp/opac_download_md/4675/p615.pdf

found 1 mention of it on the form, enncouragingly compared to lemon as well https://tropicalfruitforum.com/index.php?topic=31460.msg353093#msg353093
Title: Re: Cold hardy lemons
Post by: Florian on March 15, 2022, 02:49:11 PM
Has anyone grown or tried hanayu?

https://citrusvariety.ucr.edu/citrus/CRC3469.html
EMN, 11/23/1988: A small, yellow, seedy fruit; very sour. Somewhat lemon-like in flavor.
It doesn't say anything about hardiness but I assume its hardy like its kabosu n such.

but also interestingly I found a paper that mentions hanayu crosses (along with yuzu & kabosu) having precocious flowering.
https://catalog.lib.kyushu-u.ac.jp/opac_download_md/4675/p615.pdf

found 1 mention of it on the form, enncouragingly compared to lemon as well https://tropicalfruitforum.com/index.php?topic=31460.msg353093#msg353093

The taste of the peel and juice are very close to normal Yuzu but the fruit is much smaller. One advantage is that it is a very prolific bearer. Also, it contains fewer seeds than Yuzu but still a lot. It is somewhat juicier than Yuzu but since it is also smaller, there is not really a lot of juice. I gave mine away last year. I didn't find it "very sour" as th ucr page suggests. I certainly wouldn't consider it a substitute for a lemon.
Title: Re: Cold hardy lemons
Post by: mikkel on March 15, 2022, 05:50:34 PM
Once I ate a fruit, and all I remember is that it was the sourest thing I have ever experienced. But I have often read that it is not very sour.
Title: Re: Cold hardy lemons
Post by: Pandan on March 15, 2022, 11:42:38 PM
Interesting, I wonder if like kabosu its only sour before ripening? In any matter I find it more interesting than standard yuzu even if the size is small.
Title: Re: Cold hardy lemons
Post by: Millet on March 16, 2022, 11:17:08 AM
For my 2 cents worth.  My opinion is, all of the various Yuzu strains and yuzu hybrids are simply not worth investing ones time and money in growing them, and most especially if your  intent is to eat any of them.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 16, 2022, 09:12:27 PM
For my 2 cents worth.  My opinion is, all of the various Yuzu strains and yuzu hybrids are simply not worth investing ones time and money in growing them, and most especially if your  intent is to eat any of them.
I have a different opinion from you. I can understand why some people would say that. Yuzu is not really a "high quality" fruit, compared to any normal lemon. But it has no bad off flavors, is definitely possible to eat, and is pretty hardy and cold tolerant for a lemon. That combination of hardiness with edibility could be a good starting point, in my opinion. It may not be an excellent fruit, and it does not have the level of cold tolerance of poncirus hybrids, but can you find any other citrus that is as cold tolerant as Yuzu which tastes as good, or is as edible as Yuzu but is more cold tolerant? I don't think you will.
Yuzu is great to add flavor to other things, and especially the peel is tender, not too bitter, and has lots of flavor. Something else to keep in mind is that harvest time does matter.

Those who say Yuzu is terrible, I have to imagine that those people live in a zone 9 or 10 climate where they can grow better tasting citrus varieties. Once you get into zone 8, your options become more limited, and then Yuzu might be something you might want to consider, if you want to be able to grow anything outside.

Unless you value Yuzu for the peel and understand how the peel can be used, I can see how some people might not understand how Yuzu is worthwhile to grow. But the inside is edible. Although it can be a little watery and bland, the inside flesh is a bit dry, does not have much juice, and of course the inside is packed full of a large number of large-sized seeds that take up a large volume of space. I get a lemon, sour orange, mandarin orange, and a little bit of almost grapefruit flavor from the inside segments.

When I say the inside is edible, perhaps I mean something that a child would snack on and forage for in the wild, or that you could eat in a survival situation.

Yuzu has a very fragrant and unique smell, that to some people compensates for its low quality fruit. The important thing is that the fruits do not have bitterness, like some other fragrant orange citrus fruits.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 16, 2022, 09:29:49 PM
Interesting, I wonder if like kabosu its only sour before ripening?
I have had one picked from the tree that was fully ripe (but grown in a cool short season climate).
They are about as sour as a Meyer lemon, but just a little bit watery, bland, and insipid inside. They might be a little less acidic than a Meyer lemon due to being watery. This was when it had reached a full yellowish-orange color.
You want to pick them when they are still mostly green.

The peel makes a good marmalade at this stage though, when they are orange.

I will say that the inside quality of Kabosu, fully ripe, is definitely better than Yuzu, if you are only focusing on eating the inside. It is a little like Yuzu, but also like a Meyer lemon and even maybe just a little bit like an orange. Not great flavor, but definitely edible inside. Though this is still not something you would buy from the store if you were only wanting it to eat the inside.

Lastly, I will say that the leaves on my Sudachi survived through a zone 8a Pacific Northwest winter, but I think that was only because the trunk was bent down by the weight of the snow causing the entire plant to be buried under the snow. If it had been exposed to the above air, the leaves would have been completely fried and there would have been severe stem damage and branch death.
Title: Re: Cold hardy lemons
Post by: JohannsGarden on March 03, 2024, 06:51:16 PM
Stan's "citremon" hybrid seems like a pretty good candidate.  It's not listed on his main website, but he has a post about it on Facebook and someone visited him and made a video about it.  It's a trifoliate/lemon hybrid.  Looks like yellow pumpkins, but apparently has a very true lemon flavor profile.

https://www.youtube.com/watch?v=-6pFqH1IMsM&t=50s (https://www.youtube.com/watch?v=-6pFqH1IMsM&t=50s)

https://www.facebook.com/permalink.php?story_fbid=pfbid06JxkL1ozkLeawKzR7tyKNfp3A1QRhoFAcjBNJZ8Z4GFvZUzM2Gu2VKUD7SdvdGSTl&id=174405135904728 (https://www.facebook.com/permalink.php?story_fbid=pfbid06JxkL1ozkLeawKzR7tyKNfp3A1QRhoFAcjBNJZ8Z4GFvZUzM2Gu2VKUD7SdvdGSTl&id=174405135904728)
Title: Re: Cold hardy lemons
Post by: Mulberry0126 on March 04, 2024, 07:57:17 AM
part 2: this is extra messy
2.) hybridization   - Using already available cultivars to breed something new

In order to do this I needed information on what to select for. I used Hamlin orange as an approximate example so people know what I meant in the first post.

Basic criteria:
○A history of taking below freezing temperatures
▪︎(for actual lemons close(r) to freezing, at least hardier than standard)
○Ripens before dec, preferably oct-nov
○Lemon flavor / sour

points made by members:
>Frost destroys fruit so we'd need something that sets before frost.
> as @ pointed out lemons can take 9 months ??
> "cold hardy" is relative for the 2 or 3 big, warm citrus states (CA, FL & TX)


(From here you can go through the thread and see my thought process as you all helped me eliminate or reconsider many choices.)

Project goals:
An improved, hardy lemon tasting citrus - must be able to survive zone 8a to zone 7 no protection and fruit before frost.

Project notes: for zone 8 there is decent hardy citrus besides mandarins. They aren't very flavorful, not sour and don't have lemon flavor notes.

Further projects:
Using poncirus crosses to get a deciduous lemon - this would take generations

From here I decided I'd try to use Harvey, Meyer, Citremon and Ichang lemon (while keeping an open mind) and my initial planned crosses:
Meyer x citremon
Meyer x harvey
IL x harvey
IL x citremon

Knowing meyer & IL are monoembeyonic would save a lot of concerns about cloning. The F1s would be bred to each other.


Lemon choice alternatives:
Sunquat(?)
Genoa
Interdonato (? fall bearer + greater citron heritage)
Bearss lime (NOT hardy but monoembryonic, low seeded & crops in Oct, perhaps a start for a hardy lime spin off)

Hardy citrus* of interest :
Ichang Papeda - CRC 3931
Khasi Papeda - CRC 3052
Citrus Hongheensis - CRC 3797

Hyuganatsu (bland yuzu pomelo hybrid I havent tried, but its heritage is similar to Ichang lemon which I like and supposedly its not too seedy)

Citrangequats? (Could dilute lemon flavors too much)
note: Ive heard ichang papeda x poncirus crosses lend to less bitter hybrids (n1tr1 is supposedly one).
But ichang lemon isnt papeda - a forum expert (ilya) said its yuzu x pomelo. Would this mix challenge any off poncirus flavors? Does it matter? No but still something to look into anyways.

* this was just a quick list

Smaller things thatd be nice:
•Bright yellow rind & flesh - hardy varieties tend to be so dull
•A flavorful rind
•Shape, Id prefer that pinched end oval shape but beggars aren't choosers
•Smooth rind
°"Juicyness"? Most of this can come later


-

IF any of you know the gene(s) related to hardiness and flavor you can use program to
https://colab.research.google.com/drive/1ShEUyKkSrhGRADCw9ertgjF5OrfNTjSW?usp=sharing
•Details on how to run (need google account sadly) and creator here: https://www.facebook.com/groups/PlantBreedingForPermaculture/posts/1989725684524388/

Other ideas; I want to reach out to an org that helps organize collaborative plant breeding

I don’t know all the agricultural terms and please excuse any presumptive-ness as that’s not my intent.


Funny enough, Meyer lemon x Citremon is a cross I just attempted too. Some of my Citremon grafts took and flowered right away so I used the pollen to pollinate some unopened Meyer lemon flowers. Suspecting Citremon is already a trifoliate orange x Meyer lemon cross, this would be considered a back-cross and may yield a hardier lemon with acceptable flavor.
Title: Re: Cold hardy lemons
Post by: a_Vivaldi on March 04, 2024, 09:05:23 AM
Oh very nice! I had been thinking about getting a citremon to do that exact cross.
Title: Re: Cold hardy lemons
Post by: Mulberry0126 on March 04, 2024, 09:28:20 AM
Oh very nice! I had been thinking about getting a citremon to do that exact cross.

It's an easy one too since they should be compatible and Meyer lemon is zygotic and blooms prolifically so plenty of chances if one doesn't take!
Title: Re: Cold hardy lemons
Post by: a_Vivaldi on March 04, 2024, 11:14:42 AM
Good to know. I might look into getting one next year. How's the cold hardiness of it? I'd assume decent given the trifoliate parentage.
Title: Re: Cold hardy lemons
Post by: Lauta_hibrid on March 04, 2024, 12:46:14 PM
Good morning.  One of my goals in my crosses was to generate "cold-resistant versions of Lemon" and as the largest tree and with 33% Zygotic seeds 👌🤗, it was my Genoa lemon I started with this one.  I have Genoa and Lima Rampurg x Poncirus plants.  but then also cross with Seville bitter orange (since it is a cold-resistant plant. Also "Orangequat" is a very good parent, it is always juicy, thin skin and terribly acidic!! it is monoembryonic and resists cold, and one that does not I know if it will be resistant it is Genoa lemon x calamondin. This year I will have seeds from an even more complex work of: Meyer x Poncirus, orangequat x (Buddha's hand and Poncirus), lemon x (Citrange troyer and Yuzu), nagami x Buddha's hand kumquat Nagami x Poncirus, chinotto x (Poncirus and etrog), Pummelo x (Poncirus, Citrange troyer and key lime, buddha's hand and calamondin)
Title: Re: Cold hardy lemons
Post by: Mulberry0126 on March 04, 2024, 03:12:44 PM
Good to know. I might look into getting one next year. How's the cold hardiness of it? I'd assume decent given the trifoliate parentage.

Apparently they can handle brief dips below 10°F but I think it's less hardy than a citrange or citrumelo. We're testing some out in the field here so we'll see how they fair this coming Winter.
Title: Re: Cold hardy lemons
Post by: Mulberry0126 on March 04, 2024, 03:13:49 PM
Good morning.  One of my goals in my crosses was to generate "cold-resistant versions of Lemon" and as the largest tree and with 33% Zygotic seeds 👌🤗, it was my Genoa lemon I started with this one.  I have Genoa and Lima Rampurg x Poncirus plants.  but then also cross with Seville bitter orange (since it is a cold-resistant plant. Also "Orangequat" is a very good parent, it is always juicy, thin skin and terribly acidic!! it is monoembryonic and resists cold, and one that does not I know if it will be resistant it is Genoa lemon x calamondin. This year I will have seeds from an even more complex work of: Meyer x Poncirus, orangequat x (Buddha's hand and Poncirus), lemon x (Citrange troyer and Yuzu), nagami x Buddha's hand kumquat Nagami x Poncirus, chinotto x (Poncirus and etrog), Pummelo x (Poncirus, Citrange troyer and key lime, buddha's hand and calamondin)

Wow that's a lot of different combinations! Lemon x Yuzu would probably taste/smell delightful.
Title: Re: Cold hardy lemons
Post by: SoCal2warm on March 16, 2024, 01:45:57 AM
I can share my experiences of an Ichang lemon growing in the U.S. Pacific Northwest climate region, climate zone 8a.

It started off in a container outside.
One year, during a cold winter, the plant was severely damaged and suffered much die-back. It was much more damaged than two Bloomsweet grapefruit plants that were right next to it. So I thought this showed that Ichang lemon was not very freeze tolerant.
But then another year it went through a winter colder than the first, and the Ichang lemon seemed to survive through it well, while the two Bloomsweet grapefruit plants ended up being killed.
The plants growing in containers were not far from the house, and got only moderate sun exposure during the winter.

Then I put the Ichang lemon in the ground, in a very sheltered spot on the south-facing side of the house, up against a wall. It was not covered or otherwise protected in any way. It was a moderate winter, with mild temperatures most of the time, but three days of moderate freeze, outside temperatures probably going down to maybe around 13.5 to 14.5 °F ( -10 °C).
It seems to have survived well, and as of March 15, the leaves are not looking too unhealthy, looks like it will do well and grow a lot this year.

I can also point out I planted two small Ichang papeda plants in the ground, further away from the house, and both of them did not end up surviving. Declined a little bit after going through the first winter, and then were finally killed by the second winter, even though the second winter was not as cold as the first. Yuzu seems to grow faster and recover better than Ichang papeda here, but Yuzu can also show decline and be killed.
In this climate, it seems very important to plant in a protected spot, very close to a house, in an area that is not as open and will not get much wind blowing across.
Title: Re: Cold hardy lemons
Post by: a_Vivaldi on March 16, 2024, 02:02:20 PM
I'm similarly in 8a, though probably closer to 8b than SoCal2warm. And I'm 8a in the South, which is a whole lot of different from the PNW.

My ichang lemon was purchased as a seedling last year. It was about 10 inches tall and quite yellow from neglect at the nursery.

Planted in spring, it put on good growth, reaching 2 ½ feet by late fall. A really early hard frost defoliated the top leaves, and by the end of winter it was mostly defoliated. The winter was pretty mild but had a few solid freezes. The low was 17 F.

It's now flushing new growth, the first of my plants to do so. Nearly had a late frost this week which would've been trouble with it growing so early.

As an interesting comparison, the keraji seedling I also got grew faster, reaching an impressive 3 ft 4 inches, but was winter killed. It almost survived by the like of things, the stems showed signs of life until February. A somewhat larger changsha put on almost no growth, remained yellow through the whole year despite adequate fertilization, and died after the first frost. Not representative I suspect.

Anyway, here's my ichang lemon.


(https://i.postimg.cc/cvwjDTP2/IMG-20240316-102336679.jpg) (https://postimg.cc/cvwjDTP2)
Title: Re: Cold hardy lemons
Post by: caladri on March 16, 2024, 11:56:55 PM
How old was the keraji seedling when killed?
Title: Re: Cold hardy lemons
Post by: a_Vivaldi on March 17, 2024, 02:01:30 PM
I had it for one year, but I bought it as a one gallon pot. I'm guessing it was about one year old, so it would have been two years old. Might have been two years old when I bought it, in which case it would have been three when it died.