Hi Clark,
What is so attractive to you for this fruit variety? Is it the strength of rootstock or the fruit itself? The fruit appears very small but perhaps it makes a good jelly? From @TRAV recent posting it appears that many plum varieties are compatible so if that turns out to be true then I would think that Adara and most of the Prunus cerasifera varieties would be good interstems for grafting most other stone fruits. I have been using these two interstems to topwork my mature sweet cherry trees with various plum and pluot varieties and have found them both to be very compatible. I look forward to your response so I understand the significance of your goal. Personally I want to find a source of Montmorency cherry scions but it’s a hard one to locate a source.
Dennis
Kent, wa
In the case of serotina, I can’t help but wonder if the fact that many phenotypes have the potential to form a ~80ft tall 3ft + diameter tree might be slightly problematic when used at rootstock. I have seen dwarf forms growing in secondary dunes on the Atlantic shoreline here in the northeast, though I’m not sure that their forms reflects unique genetics or, more likely is just a result of severe site conditions- salt, wind, drought, lack of N or many available nutrients.
I think @clarkinks and others, myself included, were sort of riffing on the potential for improvement, given that as wild foods go, black cherries are already sorta pretty good.
Central New York State, zone 5b more or less.
On both prunus Serotina and prunus Padus, the only ones really doing well are the little round sweet yellow plum from a friend, I’m pretty sure a myrobalan cultivar plum and American plum is doing really well on a prunus Padus (possibly actually Virginiana, I will double check). But the American plum on prunus Serotina is doing alright despite the late grafting and heat, maybe it will catch up in a week or two.
Myrobalan is apparently your Serotina interstem if anything is. An easy aspect of the that is you can buy a myrobalan rootstock and use the top as interstems, you might even get 3 interstems out of one rootstock, and of course one rootstock for grafting, which could be gifted, sold, or planted.
So in the end the Santa Rosa plum sort of worked along with red haven peach, growing very slowly.
But the good myrobalan cultivar plum I have (or hopefully it’s actually a Mirabelle) is doing great on prunus Serotina and prunus Padus.
Here is the plum I was talking about myrobalan cultivar probably, I couldn’t find a new picture, but it was grafted very late and has at least 2 gree shoots a foot long each, and on a 3" top worked prunus Padus I have a graft that’s huge 3 feet of new growth lots of branching, maybe even 3 months of growth vs one and a half though.
100% Successful:
Myrobalan cultivar (or whatever this pingpong ball plum is) on Padus is doing great, And on prunus Serotina the only winner in my test. Both survived (100%) and are growing quickly.
The might possibly work out:
1 Japanese plum and 1 peach scion survived out of ~30 scions on 3 trees.
All plums leafed out on both prunus Serotina frankentrees and on a larger topworked prunus Padus.
All peaches except one scrawny scion are leafing out well.
Almonds, I had terrible grafting material but they leafed out and grew a bit before dying, which was pretty good for the scrawny twigs trimmed off newly bought trees from the nursery.
Japanese plums: Santa Rosa (1 survived on the small Serotina) and Burbank (got eaten by ducks or turkeys)
Bush plum, specifically Nanking cherries, most died from an unidentified mold.
American plums: sweet unknown variety
Peaches - Red Haven (1 survived, the rest of the peaches failed on 2 trees), Belle of Georgia, and I believe Hale Haven
Some hope:
Almond NC-1seedling is growing well, all in one almond does not look like its working but it was bad material pruned off a just planted tree.
Cherries
Some cherry grafts died immediately some layer longer then died on the Frankenprunus trees which are Serotina. Some Survived on the prunus Virginiana along with American plum.
Just plain dead:
Apricots: Red-Yellow and Ilona varieties, all 7 grafts shriveled and died, granted the material was not great, again pruned off of just planted trees, but looks like a solid no for apricot on Serotina.
Note:
I think my apricot and almond grafting material was pretty bad so there might be hope for them.
I see the Attraction to Prunus Serotina. It is like a weed here. It would be nice to be able to graft something on it.
Woot - thanks for all the great info on p serotina rootstock here! Esp to @Trav and his frankentree! I will try sticking some p maritima scionwood on a serotina rootstock or two this season - was hoping there was already positive data/experience with north american plum varieties grafted on serotina rootstock but oh well. Let’s see how it likes beach plums next. Will post later in the spring after I dig a few seedlings up and get them stabilized. Stay tuned if interested.
-Pete
In the end my recommendation is:
Use an interstem! Mirabelle plum (it could actually be a myrobalan plum cultivar) is definitely the best!
Whip and tongue to the interstem and then graft the interstem to the tree how ever works best is a great method in my opinion and experience!
Using any rootstock variety as an interstem would be a good idea if you don’t have either of these. If you know a nurseryman he probably would be happy to give you tops off his rootstock trees, but he might not want to sort carefully. 
I should be embarrassed about the lack of pruning, but I am in Russia now and getting back and forth from the US is not easy.
In any case you should be able to see from this recent photo my father sent me that the branch above the yellow flag is still holding leaves, and obviously different from all the other branches.
I believe it is Mirabelle, and it’s definitely on prunus Serotina, again a popular variety on top of the interstem should surpress growth more.
If you’re cutting the tree down to a stump or grafting a young tree down low, i would keep the interstem a little longer, 6+ inches it might offer dwarfing properties between the two.
This was almost 2 seasons of growth, not any care since July 2023.
Mirabelle on prunus Serotina:
(Possibly a myrobalan cultivar)
Trav, are you getting to visit any interesting nursery’s?
The bark on the trunk of this tree is wrong for Prunus serotina.
That’s what I thought initially too, but I checked multiple times; it is.
I thought it would be pin cherry prunus Pennsylvanica, but no and I don’t think we have any there, then prunus Virginia, but I saw that’s very suckering and more of a bush, and I found a prunus Padus and also Grafted that with Mirabelle plum, much prettier than this: 4 feet of well branched growth in less than one season.
I probably have a close up of the leaves before grafting, I’ll look.
But I made a video of entirely frameworking the tree, so it might be too far away.
Feel free to identify it correctly for me, but I’ve checked and checked, and that’s what young bark on timber cherry usually looks like.
If you have an up close picture of the bark on the main trunk that will help us.
Black cherry has those very elongated lenticels on the younger bark and is usually not quite that shade.
I’m more leaning toward virginiana without a close up though
Virginiana and Padus are nearly indistinguishable by the leaves, Virginiana is almost useless as a rootstocks since it suckers like nobody’s business.
This is not Virginiana and we have them, and a Padus up by my parents’ house.
This is the Prunus Padus also Grafted with Mirabelle plum.
@Phlogopite
Unfortunately I haven’t but I have found interesting fruit like:
Truly cold hardy:
I found a redflesh apple that’s quit good, not reliably red fleshed, but it’s Moscow! It’s about a Zone 4 here. So it’s amazing how red it is, I didn’t think you could get real redflesh in colder than zone 7. I will be getting scions ans hopefully grafting it in the south of Russia this year.
Wild hazels everywhere here, ripe in the end of July.
Caucasian persimmon, cherry sized abundant, but hard to pick ripe, so it often falls on the ground after a few days of being finally sweet and soft on the tree, cold hardy to Zone 5, I would not recommend it over American persimmon for anything other than rootstock though, pleas don’t plant them outside their range, they could invade where American persimmons are or should be.
Sochi area
Butia: one of the most cold hardy Palm trees growing all over Sochi, a delicious Mango-ey flavored palm fruit but stringier.
Bitter dates, also hardy to about 20 F*, some are quite good.
Loquat is delicious, and one of the more cold hardy leafy evergreens.