Can someone share their experience of growing apricots on Krymsk-1 or recommend a dwarfing rootstock compatible for Harglow, Sweetheart, and Zard (the three varieties I am trying to grow)? ChatGPT recommends Krymsk-1, but I actually got a Sugar Pearls on Krymsk-1 from an acquaintance gardener here and added Zard, Harglow, and Sweetheart grafts to it – and have not had a good experience: And after one year of growing well, the Sugar Pearls branch died off (shortly after leafing out in Spring last year), then this Spring the Harglow branch did not wake up (again, in its third leaf-year, after growing like crazy in its first leaf-year and struggling in its second). And how Zard seems to be not doing well (after producing its first nice crop last year and having grown beautifully, this year the leafs look dry and curled into tubes, just like Harglow looked last year before dying this Spring). The Sweetheart still looks fine, but it’s the youngest, only in its second leaf – at this stage Zard also looked great. So, I don’t know - perhaps my friend misidentified his rootstock, or perhaps Krymsk-1 is not as compatible as they say it is…
I have Harostar on Krymsk 86 and it’s doing good so far in terms of growth and winter hardiness. Zard on citation, planted right besides Harostar, did not survive late frost and died. I believe citation rootstock is a main cause of a sudden death, roots seems to be dead.
You might try grafting your cots to Nanking cherry -prunus tomentosa. It’s severely dwarfing for stone fruit.
My only experience with it, though, is grafting an unknown apricot to the prune plum that I have grafted to tomentosa. That appears to be working well, with a few fruit on second year growth, but it’s too early to tell much for sure.
Harostar was planted in spring 2024. I got one apricot this year despite the late hard frost (26°F and 22°F on April 8-9) that wiped out the large bloom the tree had.
I also have two peaches (Contender and Redhaven) on Krymsk 86, planted in spring 2024. They’re growing really well too.
Others have noted compatibility issues with manchurian-armeniaca hybrids like the harrow series and morden series on krymst 1. Krymst 86 and 99 don’t seem to have these issues, but they are very vigorous (not dwarfing). Tomentosa and Besseyi are severely dwarfing, resulting in shrubs, not trees. Maybe citation would work?
Your tree looks beautiful, but not enough time has passed to judge. I hope yours stays like that. Mine grew almost as nice for the first couple years, and then started struggling. (As I mentioned, Harglow didn’t wake up this Spring, and Zard is following its footsteps but year behind. I expect it to die next year.)
Interesting information, thanks! Could you expand on your message a bit for a novice like me – which one of Zard, Harglow, or Sweetheart is Manchurian-Armeniaca hybrind and which one is a morden series? (Did you mean “modern”?). And thanks a lot for the tips on Tomentosa and Besseyi. I will look into them (shrubs are OK by me, I think).
None of yours are from the Morden, Manitoba (not modern, actually pretty old) breeding program, which incorporated a large percentage of Manchurian parentage, which is likely where the incompatibility with K1 comes from, but Harglow is from the the Harrow program with included Morden varieties as parents. I don’t think anyone has done rigorous testing on this, and apricots can be difficult to graft, so you may want to try a few more times with K1, but be quick to give up if you keep having issues.
Ouch… Each try is a multi-year proposition because the issues transpire after 2-3 years from grafting (again, it’s not that my grafts did not take but that the branches they produced eventually failed). I just turned 70 this July, I don’t think I have a sufficient time horizon for multiple tries! I was hoping to ride on someone else’s experiences rather than creating my own :).
Oh, and one further thought on this: are there apricot cultivars that are proven to be compatible with Krymsk-1? And if so, would it make sense to use that compatible cultivar X as an inter-stem graft, and then graft the questionable cultivars I want (Zard, Harglow and Sweetheart) to Krymsk-1 through X? Would this solve the compatibility issues? (By the way, the reason I am focusing on those three cultivars is because, from my reading up on them, they seem both among the most frost-tolerant and best-tasting apricots available (I am in NE Ohio, so late frosts are definitely an issue.)
You could also use a compatible rootstock as an interstem, especially if you still have the established krymst 1s alive in the ground. Krymst 86 or 99 would work well, and their vigor would be limited because they wouldn’t have roots.
Other favorite late-blooming great-tasting apricots of members here include Orangered and Tomcot. Sweetheart dosen’t seem very popular here and Zard can be sometimes take a long time (8+ year) to produce well. Harglow is very late blooming and can acheive good size and quality if well thinned.
Thanks, @MinnesotaApricot, for all your helpful information! Sounds like I do have some options. It’s interesting to see how experiences vary from one orchard to the next. You said Zard is a late producer, but for me, it fruited on its second leaf, along the entire length of the shoot that grew the previous year! (That was last year, and this year it dropped all the fruitlets and, as I mentioned, seems to be dying.) I heard lots of good things about Tomcot but from what I read the three I am trying to grow are later still. (And from a brief look on the Internet, Orangered is in a similar category, later than most but not by much.)
I did not really keep records, mostly because I could never figure out which point conventionally signifies the blooming time – the pink bud or the first fully unfolded blossom or the peak bloom. What I can say is that the one year when I had Sugar Pearls, Harglow, and Zard all bloomed, there was a substantial overlap of all three (I remember thinking they can all pollinate each other), so whatever differences were between them, they were not significant, your observation of couple days sounds about right.
Hi again, @MinnesotaApricot - To follow up on your interstem suggestion, do I put both the interstep graft and then Harglow on top at the same time or should I wait a year for the interstem to take and only then graft the Harglow to it the next year?
Yes Thanks @MinnesotaApricot good information. I do enjoy a little background.
I have read on the internet probably, possibly on GF that apricots do best on plum rootstock. If you have plum bud to it then graft to K1. That is my plan. If I remember correctly compatibility with peach is shorter term than plum. And peach compatibility on K1 is questionable at best.
