Of course, and I’ve long since conceded that. All I’m suggesting is that there may be more than one strain of Mt. Royal or Hilltop was selling the wrong thing under that name.
That debate is over and I conceded your point- you win and I’m grateful for learning from you. But I want to know if your Mt Royal bears every year for you the way my Hilltop version did for me and the round version has not.
My Mt. Royal bears every year. One year heavily, the next moderately but I don’t have to worry about a drastic drop of production like mirabelles have been.
How did you come on it… I’m not clear although I probably should be. Did you order a Valor from Adams?
The Valor/Mt. Royal debate/mystery/resolution needs no rehash.
I find plums very mysterious in how they respond to different sites in terms of reliable cropping. My current version of Mt. Royal seems an unreliable cropper even when surrounded by many potential pollinators. True Valor is less variable for me, but at some sites still less dependable than others. Empress, Castleton and Stanley are the most reliable prune-plums I work with.
A possible discussion point on Mt. Royal however-
A non grafted Mt. Royal from the reading is a natural semi-dwarfing tree. And in turn sends up and gives suckers
I believe that St Lawrence sells them this way… whereas other nurseries and most folks reviews on here have been from grafted examples.
Raintree i think lied in their Q and A of this plum.
I only bring this up because Stephan tends to make videos of interesting things and he did a video of digging up Mt Royal suckers and planting them in new rows.
So a few points to ponder is that this may be a good tree to have not only for the great fruit… but sending up suckers that are true are nice for folks that want more semi dwarf trees… but possibly also nice for folks that want a semi dwarfing hardy rootstock.
It may have been discussed already but… i have seen old writings of various plum rootstocks that discussed ‘consistant crop’ such as Lovell. I have not read enough nor have the experience to compare and contrast whether if one person has Myrobalan and another has Citation that one gets better or more consistant crops.
The variation in Mt Royal is that some folks may have it on its own rootstock… which i am also not sure if that makes it more or less ‘consistant’.
If one person on here has ‘consistant’ crops then i think there may be knowledge in which rootstock gives them that. As well as vice-versa.
I dont mean this to be investigative or a debate…but just curious if there is knowledge to be had.
Interesting… I asked CHAT about creating new trees by stooling. Doesn’t seem easy. CHAT isn’t reliably accurate, but it certainly accesses a lot of accurate information. If it is right about this, own root Mt. Royals are likely rare. As far as rootstock and reliability, I have observed no difference between Myro and Citation- although this is not based on careful evaluation. .
Yes — Mount Royal will stool, but it’s not a naturally strong stooling genotype.
You will get some rooted shoots, but nowhere near the productivity of classic clonal rootstocks.
Mount Royal sits in the “doable but not commercially efficient” category.
Nurseries historically avoided stooling most Euro-plum cultivars because:
Mount Royal behaves like a typical P. domestica dessert plum: you can coax it, but it won’t behave like Myro.
You’ve hit on something that I never observed or understood, but could be important to plum growers and an issue with varying annual production of Mt Royal. Bear with this long CHAT explanation and thank you for contributing to my fruit tree education.
Yes, but only through the rootstock’s effects on:
Rootstocks for plums do not directly impose “biennial vs. annual” bearing tendencies the way they do in apples (M9 vs seedling, etc.).
But they strongly modulate the conditions that create reliable cropping.
This matters especially for Japanese plums and pluots, which are far more sensitive than European plums to:
All of these are influenced by vigor → which rootstock controls.
3. How plum rootstocks differ in their effect on croppingHere’s what matters for annual reliability in plums, in order of importance:
Excess vigor → reduced flower bud initiation.
This is why people get maddening variability in varieties like:
A highly vigorous rootstock pushes:
Rootstocks ranked by vigor influence (approximate):
Very vigorous
Moderate
Moderate-to-weak
For Japanese plums and pluots, the more vigorous rootstocks reduce cropping regularity; moderate vigor stocks improve it.
This matches your orchard experience:
When you keep canopy open, light penetration deep, and vigor in check → annual cropping improves dramatically.
Rootstock contributes a lot to that baseline.
Larger trees (both seedling and vigorous clonal stocks) store more carbohydrates, which:
A big Japanese plum on a semi-vigorous rootstock is more frost-tolerant cropping-wise than a small tree on Krymsk 1.
This is why Mount Royal as a rootstock can give reliability:
decent vigor → good storage → more “insurance.”
Some rootstocks push a variety into bearing before the wood architecture is stable.
This can create biennial issues if the tree sets a huge crop too young.
Plums with early-bearing rootstocks (like Krymsk 1):
If you thin them well, annual cropping is good.
If you don’t → they swing wildly.
If the scion–stock combination is slightly incompatible (not common, but it happens):
Flavor Supreme is notorious for acting differently on different stocks.
Some pluots behave almost like they are mismatched grafts.
Rootstock affects:
A vigorous, water-pushing rootstock can advance flowering slightly, which can reduce reliability in cold pockets (your property is perfect for observing this).
4. Where Mount Royal fitsMount Royal used as a rootstock gives:
Thus, it tends to produce fairly reliable annual cropping, assuming the scion is not innately biennial…
Chat does suggest that the issue is much more important with J’s than E’s.
I’m surprised to see Marianna in the Very vigorous category. My own search returns:
The above says Marianna and St Julian are both 10-15 ft, though it also says St Julian is 12-17’. On the other hand, Raintree says Marianna is 80% size and St Julian is 75%. Seems about the same.
This question has some relevance to me, as there are a number of suckers from a Marianna 2624 tree in my yard that I am planning to dig up and establish a new planting from, at another property. I’ll be either transplanting or eliminating the mother tree, so I should be able to get a lot of roots with the suckers, hopefully giving the trees a faster start than whatever rootstocks I could buy online.
Another possibility I have is to take some of the roots (there are always some broken ones, no matter how careful…) when transplanting a plum on Krymsk 1 and graft scions directly to the root. I haven’t tried that with plums before, but it has worked well with jujubes. At least for good sized root sections- just a few inches isn’t enough, but 8-12"+ works well.
