Hi everyone from sunny south-west Wales!
I have a question on interstem grafts I hope you can help with.
I have some M9 maidens which I grafted last year. Since then, I have realised that my site is not overly suitable for M9s, and I really should have gone with M9>MM111.
So my question is - has anyone ever tried to take a maiden tree entering its second year, cut it at its base and graft it onto another rootstock? I'm thinking such a graft would want the scion growth cutting back and would need support until the join healed.
I want to salute Paul Robeson singing to the striking Welsh coal miners.
I can try to answer your question as I understand it. I've done a bit of this. After grafting a rootstock, I have chopped it so that the remainder will be small, easy to graft and go straight up. Then I have grafted onto that. What I just mentioned works. I don't know if that answered your question, because I don't know what a maiden tree is.
I am pretty sure the mention if followed correctly is that the ultimate goal is to have an apple cultivar grafted on M111 with a M9 interstem. I think the part he says in the last sentence is way over thinking it so if you leave that part out then it's appropriate to say that - his cultivar that's joined to the M9 can be treated as a single section of scion wood just the same as if it were never grafted at all.
M9 has universal compatibility with all known apples that I know of, at least it's put out that way. Another known fact is that the longer the interstem of M9 is, the more dwarfing your cultivar becomes.
This year I want to do something in double grafting in one shot. I want my Peach scion to graft to another plum that needs Toka plum as an Interstem in order to guarantee the Peach has the most compatible plum under it, and peaches are known in California experiments at least, that Peaches there do well on Toka. So I have taken Toka and my Peach scionwood already in the dormancy so as that no buds were seen popping. I will essentially be doing the same thing this year that I think you are going to get accomplished. ...and I have done this in the past with lots of previous worries of incompatibilities too but this double way of grafting worked reliably for me the first time.
Thanks for the replies - I'll try to be more clear.
A 'maiden' is a year-old tree that was grafted last season. The M9 maidens I'm talking about were rootstocks last winter, and I grafted scions on to them. Now they have had a year to grow and are about to enter their second year.
I want to cut them at the base and graft them onto an MM111 rootstock, which is much more suited to my site.
As Rooney says, the goal is to have an apple cultivar, MM111 rootstock with an M9 interstem (to create solid root systems without the 4/5 metre high tree).
I'm unsure if this will work, because:
1. The scions will be fairly large and the M9 will likely be thicker than the new MM111 rootstock!
2. The M9 rootstock will now be entering its third year of growth (one year at the nursery which cloned it and a second year after I grafted onto it). I have been told that scions should be a year old... but I'm not sure that's true.
Asking this question to try and not waste time (and trees!) in a misadventure.
John - I'll be checking out the film The Proud Valley now I've read up on Robeson.
The main concern would be the size of the scion combination and the combined juvenile state of the combination. Nobody that I have seen had put out any reasoning behind this that I have ever seen but here we go:
The more mass and more maturity of any grafting on the upper side amounts to a more mature immune system that with the extra mass is very capable of learning and acting that there are enough unrecognizable differences in the underneath point of contact and quickly isolate it as it would an infection.
Lots of this is still a hypothesis but this seems to be what I recognize of it. It's likely your cultivar is mature because scions are commonly taken from high at the point of flowering (ie. maturity). It's likely your MM111 is juvenile because it most likely originated from Tissue Culture (TC). Same with the M9.
Thus I think the biggest challenge is surface and water loss at this point the way I understand this to be. Then reduction of the upper portions and also complete coverage of the scion area to be grafted is essential so that the scion won't dry out before a union is accomplished.
The notion that scions need to be a year old or less stems from an accumulation of diseases, which is less common in apple than stone fruits.
A faster recovery and less dehydration will occur if the wood is compressed tightly. But it's your turn so I won't delve into the recommendation of grafting methods at this point quite yet.
I have been grafting dwarf interstems onto apple seedling rootstock, as I'm getting older and may not always want to climb on tall ladders. Plus, I'm trying to graft some edible crabs onto a tree to bring to school so the kids can eat them and not remove all the fruit in one day.
Yes, one year scions are best. The most important thing is to get the same diameter of new scion onto hopefully a one year growth of rootstock, so the cambium layers can match. When I notice that a rootstock has grown too big, I often chop it and try again the next year, or budding in the summer.
The case he is illustrating is a thicker scion than the rootstock John, which then needs compensation in some way or another. A method I know of which has been copied over in propagation practices is to bench graft and submerge the whole thing after grafting in peatmoss.
The method and temperature requirements etc are disclosed inside of a two page document. The only applicable part here is in the right hand side of the page-1 of the document of using these in a google search engine:
site:arnoldia.arboretum.harvard.edu "well+covered+with" high+level+of+bottom+heat
Since peatmoss is a clean substance then there will be no disease to trigger an immune attack and so it's best to never seal it so that it can heal faster in the presence of the most oxygen. The heat source is intended to be far enough away from the top and to prevent an immune response from the more mature parts that need to remain cool.
When after about maybe 6 weeks then Doc Farwells sealing compound is one of the things that is okay because it's a product stiff and durable enough to possibly add enough strength to the union you will need prior to planting it in your whole and staking it.