Looks like about six different people on this thread claimed to be experts. As usual, the experts here disagree.
DijonG is the only one who quoted a source, so I’m going to disregard all the other “experts” unless and until they can provide something better than “trust me bro, I used an AI” or “trust me bro, I used to teach entry level classes in a completely unrelated subject.”
@a_Vivaldi
The reality is that I have offered corrections to many statements regarding logic and botany, and the only one under contention is the taxonomy of M. rubra.
For justification, the proponents of the alternate theory offer (1) extrapolation and (2) an 18th century opinion from C. Linnaeus. You however, have chosen to engage in a personal attack. It has no merit.
I’m guessing you didn’t bother to read the source DijonG provided.
That paper showed that, even as long ago as the 18th century, it was known that Morus rubra is not purely dioecious. This is still the current scientific opinion. Nowhere in that paper do they add that “Linnaeus, however, was wrong. Morus rubra is in fact dioecious” or anything to that effect.
So DijonG provided evidence that this claim:
Is wrong.
Some other papers also showing it to be wrong:
Both M. alba and M. rubra are reported to be dioecious or monoecious (Berg, 2001;A. Whittemore pers. comm.)
Systematics and Reproductive Biology of the Genus Morus L. (Moraceae)
Nepal, Madhav P. Kansas State University 2008. 3325640.
This study presents findings on sex expression and sex ratio variation in two congeneric tree species, the native Morus rubra and the exotic M. alba, in the Flint Hills region of the Great Plains in the United States. Both species exhibited a subdioecious breeding system (with male, female and hermaphrodite individuals co-occurring within populations)
BREEDING SYSTEM AND SEX RATIO VARIATION IN MULBERRIES (MORUS, MORACEAE)
Madhav P. Nepal, Carolyn J. Ferguson and Mark H. Mayfield
Journal of the Botanical Research Institute of Texas
Vol. 9, No. 2 (30 NOVEMBER 2015), pp. 383-395 (13 pages)
Morus rubra L. and M. alba L. (Moraceae) male and female plants, located in Denton, Texas, USA, were used for this work. Although mulberry is dioecious, it is not uncommon for an individual plant to bear both staminate and carpellate flowers
Phytoestrogens and floral development in dioecious Maclura pomifera (Raf.) Schneid. and Morus rubra L. (Moraceae)
Camelia Gabriela-Anca Maier, Kent Dean Chapman, Don Wiley Smith
We have found populations of both M. alba and M. rubra in the eastern
Great Plains to be subdioecious, with the majority of individuals producing catkins of a single sex but with some (ca. 10%) being hermaphrodites
Identification of Eastern North American Morus (Moraceae): Taxonomic Status of M. murrayana
MP NEPAL, MH MAYFIELD, CJ FERGUSON - Phytoneuron, 2012
Well but THOSE “rubras” were all actually hybrids because all of these observations were after Alba came and turned everything into a hybrid /s
I believe you’re reading intention into mere statements of fact. I simply reiterated your own justification. When pressed, you provided your experience as a math instructor to back up your credentials. Here:
That was your justification. But as you know, engaging in pedagogy isn’t an exercise of the scientific method. Nor does it constitute a credential. Hence why I then rated that justification as the same as relying on an AI: it’s unsubstantiated.
In other words, feel free to provide evidence for your opinion. Until then, I will continue to treat it for what it is: your opinion. Nothing less, nothing more.
That’s just how science works mate. If you find that to be a personal attack, I’m not sure I can do much for you. I’m a data scientist, this is how it works.
I’ll readily agree that the rubras do not approach the ‘everbearing’ hybrids for productivity.
That said, I don’t know that I’ve ever sampled a ‘bad’ M.rubra berry - though some are notably better than others.
I had an east-central AL (z8) M.rubra selection (‘Dumpster Delight’) that I would put up against any everbearing hybrid I’ve grown for berry size, flavor, and juiciness, but alas, it either was not reliably winter hardy or incompatible long-term with alba or hybrid rootstock… died out on 3 different occasions, and the ortet was dead the last time I visited it, some years ago.
(Darrel - Our mutual acquaintance, Mr. Hardy, at Rogersville, has sent me photos of M.rubra trees on his farms, so some still exist in Lauderdale Co.)
I’m not sure of her source, or if it’s just anecdotal, but Eliza Greenman, at the Savanna Institute has posited that hybrids with M.rubra as the pollen parent are more ‘fit’ than the reciprocal cross… I’m not sure if she’s referring to overall vigor, fruit production, fruit quality, or what…
The team working on the M.rubra SARE grant did not (yet) fully sequence the M.rubra genome, but felt comfortable that they were reasonably able to differentiate M.rubra, M.alba, and hybrids, based upon the current state of their genetic analysis… which continues to be honed.
Final (current) report, linked below, with embedded links to protocols, etc.
https://projects.sare.org/project-reports/fnc22-1338/
I realize this thread was started with the subject being cold hardy to stuff like USDA zone 6 or 5, but I’d be curious to get people’s thoughts regarding say zone 8 or 7.
There are a lot of really nice mulberries that aren’t reliable or simply can’t be grown even in most of zone 8. Morus nigra sounds like a dead end given it’s wild ploidy and other issues. Anyone have thoughts on strategies for getting better hardiness from other subtropical mulberries?
I think the very high quality pure Albas from eastern Europe are very promising, Shelli, Black prince, and Galicia aka Galicija
Potentially Taylor #1 as well
Cross those with Lucky’s Daugherty #2 or Dijon’s mostly female mulberry and I like your chances
Lucky, I agree that M. rubra tends to have decent flavor. Production is the missing component most of the time. I don’t have enough experience with mulberry yet, definitely need to find more trees and sample more fruit. That doesn’t mean I haven’t sampled some that were worth eating.
Evidence in the form of tons of trees growing in this region suggest that pure M. rubra is better adapted to this climate than M. alba. I could definitely see a rubra parent having a positive effect on cold tolerance in crosses with other species.
Re cold tolerance, there are several options for making crosses that would produce varieties capable of producing in zones 5 to 3. IMO, the best cold tolerant alba crossed with a rubra from northern tier states would have excellent chances. But as with many things genetic, this is just a guess.
My original idea was to cross subtropical varieties with rubras from the north, but I had some personal & mechanical issues that left me stranded in Florida this year.
One challenge with that route seems to be keeping the mother trees isolated from other sources of pollen, especially since M. rubra is known to produce far less pollen than albas & hybrids.
It’s too soon to really tell, but most of the seedlings from my hand pollinations with M. rubra look identical to those hand pollinated with male ‘P2-SG’ catkins - only two of the seedlings are a flatter, darker green with a rough texture to the leaves. I also experimented with planting seeds from flowers I didn’t hand pollinate, & open pollination between ‘Himalayan FSP’ & ‘P2-SG’ seems to have occurred. Which brings me to the potential downfall of “my” variety: it flowers (and leafs out) in sync with the subtropical mother, & probably isn’t much, if any, more cold hardy.
I think we ought to be growing subtropical mulbs up north, in greenhouses or in pots, for breeding purposes. Although, sadly, crossing them with northern rubra populations may require preserving pollen from the previous year - and keeping the mother trees in total isolation from other pollen sources. Unless we can find more varieties like ‘Siam Jumbo’ that can be made to flower any time of year (‘Skinner’ also does this somewhat, but is one of the least cold hardy varieties I’m aware of…).
I have a few small own-root ‘Himalayan FSP’ trees if anyone would like to attempt this route & is willing to cover the shipping.
Here are my photos of the leaves of Daugherty #2, the monoecious Morus rubra. I’m tired of arguing against Richard’s opinion where he refuses to provide any evidence whatsoever for his claims. You can judge for yourself whether this is a Morus rubra, or if it’s a hybrid. I see no elements of alba ancestry here. To claim otherwise puts the burden of proof on the one making that claim.
I’ve had some success getting Valdosta to flower a second time. I don’t know what the genetics of Valdosta are, if it’s alba or macroura or a hybrid (and honestly I don’t care much either way since the distinctions between a lot of the Morus populations seems to be mostly academic/useless). I haven’t tested it yet, but I’d be reasonably confidant that for a lot of the early blooming mulberries just stripping the first flush of flowers would force them to reflush–which would align them with more temperate mulberries’ flowering times.
I’ll have to keep an eye on Valdosta and Siam Jumbo’s flowers to see if there are any males. If not, since I’ve got a lot of wild/feral mulberries around which produce pollen, any second flush flowers that set seed should produce hybrids Does Himalayan FSP have male flowers or is it purely female? Granted, it’s not that hard to remove male flowers anyway, at least for smaller, potted plants. So long as it’s mostly female, I think I’d be willing to give it a go (and can cover shipping for sure, potentially I can return the favor once I get more Siam Jumbo going, or Valdosta if you’d like that one).
Alternatively, I could force a potted male temperate mulberry to bloom earlier. That might be easier.
hmmm
Clark, if you want, I can “borrow” some cuttings of one of your improved males and put them to work fertilizing my Valdosta/Siam Jumbo/potentially Himilayan SFP and then send you half the seeds I obtain?
Someone… I’ve forgotten whom… in this thread or another one, earlier this year… observed that, in their locality, that M.alba and M.rubra do not bloom in concert, so hybridization between the two is uncommon, at best, there.
I do not have a known male M.alba anywhere about, though there are some hybrid males from the bundle of 100 ‘Red Mulberry’ seedlings purchased from the state forestry nursery some years ago (there were NO M.rubra in the bundle, and I came to find out that the forester in charge of sourcing fruit/seed made no effort to confirm identity - he just gathered from any fruiting mulberry he could find). That said, the one M.alba female I’ve not gotten around to destroying, fruits well in advance of M.rubra or the hybrids here, so even if it pushes some staminate flowers (I’ve not noticed any), it’s not likely to be generating hybrids with the M.rubra growing next to it.
Seedlings popping up here around the orchard/yard/farmstead are a mix of hybrids and those that appear to be pure M.rubra.
‘Corral’, a seedling that popped up in my blueberries is so similar to Illinois Everbearing that I initially suspected that it was an IE seedling… until someone told me it was a triploid, but if that information is erroneous, and IE is indeed diploid, then it may well be that some of the good hybrid seedlings I’m finding here are, indeed seedlings of IE, Lawson Dawson, or other hybrids which I’ve been growing for 20-30 years.
I have seen mulberries ‘switch genders’. There is one M.rubra on the farm here that was a fruiting female when I first noticed it. Visits in subsequent years found it producing only male/staminate blooms.
Just to add to the discussion, here is a leaf from a large rubra tree about 100 yards from my house. It is growing near a spring fed stream which is typical of mulberry in this region.
I was responding to Alan’s statement that AI was needed to wade through logical arguments.
Yeah, ‘Sixth Street’ blooms slightly after a heavy pruning or when a hurricane strips it bare too. I found some berries on the ortet last November, post Helene & whatever that other storm was that rolled through after it.
I’ve never noticed male flowers on ‘FSP’, & all the seeds from the FL Fruitgeek’s trees were duds (he only has females at his nursery). We have a small ‘Siam Jumbo’ at the nursery I’m living at, & I still have ‘Valdosta’ budwood in the fridge I haven’t been able to find the enthusiasm to graft.
Is ‘Valdosta’ actually a remarkable variety that I’m sleeping on?
@a_Vivaldi Definitely shoot me a dm so we can workout shipping a tree your way.
In your zone it might not be very unique. It’s a good partially subtropical mulberry that’s very vigorous and produces moderately large fruit with good flavor. So far it’s been mostly reliable for me here in Eastern NC zone 8a/b, which is more than I can say about the “zone 7 hardy” Pakistan.
At least one person in this thread has provided leaf samples to M.P. Nepal’s research program in South Dakota. The endangered nature of M. rubra is a tenet of his grant funding.
The AI quote I provided about the the wide dispersal of pure Rubra listed the source- USDA PLANTS Profile – Morus rubra
If you ask, chat will provide its sources. Is this enough?
please provide other sources for the claim Rubra is common in these states
Absolutely! Here are reliable sources confirming that red mulberry (Morus rubra) is common and widespread across Tennessee and the broader central/southeastern U.S.:
USDA Forest Service (Silvics of North America)
USDA Forest Service – Fire Effects Information System (FEIS)
Trees and Shrubs Online
North Carolina Extension Gardener Plant Toolbox
Tennessee‑Kentucky Plant Atlas
Additional Context – Widespread Use and Presence
SummarySo yes—red mulberry is indeed thriving and widely distributed in Tennessee, supported by both regional herbarium data and federal plant distribution publications.
