Resurrecting this discussion again, as the last one I pulled up from a year or so ago seems to have wandered all over the place and I never saw a definitive answer or concensus.
Was at Lowe's today over the noon hour... they had a bunch of potted mulberries with the label 'Dwarf Everbearing; Morus nigra'. I'll admit that I don't know who the supplier was... though our Lowe's is selling a bunch of Monrovia stuff this year.
Multiple stems in each pot. No graft union that I can see. Looks like a M.alba to me.
Was there ever a concensus reached as to whether or not these mass-marketed 'Dwarf Everbearing' plants are actually M.nigra... or are they just a purple/black-fruited M.alba, and the sellers figure 99.999% of folks won't have a clue...?
I bought three true M.nigras from Lucille Whitman this spring, 'cause my wife loves them and I'm committed to TRYING to grow them here for her, even though everything I've ever read suggests that they won't like the climate here in Tuckessee.
I'm not inclined to plant a trashy M.alba when I've got superior fruiting selections grafted and producing here, but if this is indeed, a M.nigra... 12 bucks isn't too much to pay to try another one.