The Tropical Fruit Forum

I'm going to create a dedicated topic for this one since it's been mentioned a few times in other posts.

I had four seeds recently germinate and can confirm that it's generally monoembryonic but of those four one was polyembryonic.

Ten years later....

I'd like to bump this topic and see what people's updated records are for cold hardy Eugenias and related plants.

Currently, I have some CORG outdoors that seem to be handling mid-twenties F without issue. Some Psidium cattleianum var lucidum out there as well that don't appear to be taking any damage. Next winter I'll test the Psidium under more exposed conditions to see if an in ground Psidium cattleianum var lucidum can survive mid-to-upper teens (assuming we get those temperatures, we usually do), and I may also test Psidium robustom and Psidium longipetiolatum, though honestly I'll probably wait until next year with those two.

Myrcianthes pungens will go outside in ground as well. I have high hopes for that one. Feijoa have been in ground for several years and are completely hardy in zone 8, zero issues.

In later years I'd like to test out Psidium salutare (from Cordoba province if possible, but that'll be hard to find), Eugenia uniflora var. Dasyblasta and perhaps some of the other Eugenias.

I've seen research that var lucidum produces apomitic seed, so it might not work as the mother. It produces lots of pollen though so it should be a good male parent.

I'm growing out Psidium robustum and longipetiolatum and plan on pollinating then with P. cattleyanum var lucidum and with each other. I think I'm about two years away from the first cross though as only my var lucidum are large enough to flower and fruit.

There is some weirdness with ploidy in the Psidium genus, but that's not always a 100% barrier.

yeah seems 7b is too generous

Agreed, though maybe possible if you got very lucky. An F2 from Meyer x Morton very much could though (Meyer as the mother).

Meyer x trifoliate would surely be hardy to 7b, or at least the majority of such seedlings would be I'd expect. If Poncirus Plus blooms for me this spring I'll be attempting that cross among a few others (among them Ichang Papeda x Poncirus Plus).

Oh, I'd love to jump in on this one! Do you know if these are the diploid or tetraploid ones?

Yes, I have lots of ideas for future crosses, and I think a Morton x Bishop cross could be very good. Here's a small list of some crosses I may attempt next season:
Calamondin x Citrandarin (942, 1279, Bishop)
Kumquat x Citrandarin
Kumquat x Tai Tri
Clem-yuz x Citrandarin (942, 1279, Bishop)
Yuzu x Poncirus
Yuzu + Trifoliate (Carolina Chimera)
Yuzu x Tai Tri
Ichang Papeda x Poncirus
Ichang Papeda x Tai Tri
Ichang Papeda x Citrandarin (942, 1279, Bishop)
Your crosses sound very interesting, I'm looking forward to seeing them in the future!

Very cool!

I just collected seed from a Thomasville x clementine cross, waiting for germination on them. I don't think they'll be any more hardy than a satsuma, but they're the only cross I made that didn't drop when it failed to rain for the entire month of June...

My own 1279 graft looks to have a delayed failure of some kind so the crosses I was planning with it are going to have to wait. The same thing happened to the Bishop citradarin I had, but none of my other grafts, so something weird is going on with those two. In the meantime I'll likely be able to try some of:

Meyer lemon x Ichang papeda
Meyer lemon x Dunstan
Meyer lemon x Poncirus+
Ichang papeda x Ichang lemon (if the latter blooms, which it might)
Clementine x Dunstan
Clementine x US-802 (looks like it might bloom this spring)
Clementine x Poncirus+
Marumi x Dunstan
Marumi x Ichang papeda
Marumi x US-802 (if it blooms)
Marumi x Thomasville

Not sure these are the exact crosses I'll make, depends on bloom times and such, but that's the general idea. Bloomsweet, Ten Degree Tangerine, Poorman Orange, US-1516, US-852, and Taiwanica are all in the works to make crosses with as well, but I don't think they'll bloom this spring. A few others are on the list but won't be happening any time soon. I might pick up a 1279 and a Bishop citandarin from you if/when you offer them for sale again.

I've considered getting Excaliber Red Lime, SugarBelle (not sure about patents on that one though), Kiyomi, Cara Cara (pollen could be an issue though...) Eremo x Shek, Kishu, Ujikitsu, and Mineola for breeding with, but I doubt I ever actually will. If my satsumas ever actually produce pollen I'll be sure to try and mix them in with something, but again, I don't know if that'll ever actually happen.

Thank you Boris for doing this analysis, it's quite interesting to read about even if those varieties will probably never make it all the way over here in the US.

"A plant from the village of Chestnuts, near the city of Chosta, Krasnodar Territory. "
Kashtany (Каштаны) near   Khosta ( Хоста) ?

I suspect that's the case.

Yeah it's definitely now zone 8a out in your direction (much like over here we're now zone 8b even though the 1990 map put us in 7b). But NC is weird. Because of the Appalachians blocking some but not all cold fronts, and more importantly because of the gulf stream and the way that NC juts out into the Atlantic ocean compared to SC or GA, the typical winter is pretty mild. But with the latitude being pretty high (large parts of NC are north of Missouri's southern border, and parts of NC's zone 8 are north parts of zone 6 in Kansas and even parts of zone 5 in Colorado), big cold waves do sometimes plunge the temperatures way, way down. Despite seeing several "zone 9a" type winters recently, I have seen single digit temperatures multiple times in the last two decades, to say nothing of the below zero temps we had as recently as the 80s.

It's for sure a climate where you either have to grow only stuff that's hardy to Pennsylvania at least, or stuff that you're willing to replant every ten years or so.

The Tri Clem Yuz might price to be very hardy if I had to take a wild guess. Most trifoliate hybrids are hardy to something between 0 F and 15 F depending on the variety, but they pretty much all have parents that are hardy only to twenty or the upper teens. This new one has Clem Yuz as a parent, and it's hardy to something around 10 F already. Combine that with trifoliate and the odds of getting something hardy to sub zero temperatures start getting decent. Not guaranteed, but possible.

Not being deciduous though will still be problematic for really pushing the hardiness. I'm not aware of any first gen trifoliate hybrids that are deciduous. Evergreen leaves can cause issues and extra stress on the plant in very cold weather, especially in dry, windy weather and if the soil freezes.

But regardless, this cross has the potential to be very, very hardy.

My 2¢ anyway. I'll be following the Mulberries YouTube channel for updates as time goes by.

Yes, thank you, I meant Joro spider.

I think he meant citrus that don't have trifoliate parentage.

The naturalized trifoliate that grow around here are intensely bitter according to my brother who's tried them. I'd guess they're descended from some of the very early introductions since they've been growing wild for decades at this point.

Here's that thread manfromyard mentioned.

https://growingfruit.org/t/what-pineapple-guava-cultivars-produce-good-fruit-in-the-u-s-south

It's a loooong thread.

The tl;dr is that they do just fine in the South, but that is better to get mid to late season varieties. And they grow best with plenty of fertilization. Pollination doesn't seem to be much of a problem for most folks.