Ashmead's Kernel apple tree with splitting crotch

[boundtothesoil]

I need advice please. I have a ten year old Ashmead's Kernel on MM106 with a terminally splitting crotch. The situation is entirely my fault, because I pruned it experimentally (wrongly) from the start. Hence, I've ended up with a 'huge narrow- angled crotch' right at the heart of the tree's structure. I'm quite proud of it in some ways as it is such a 'text book' case.
(see photos)

It was two years ago that the crotch began to split, so I tied it together with sash window cord. This seemed to work as both limbs of the tree have grown on strongly. But I had to retie the crotch this winter as the cord was strangling the trunk. Now I am wondering what to do to in the best interests of the tree, both in the short and long term.
As far as I see it I could:-
1) Keep the tie in place, retying each year until the crotch finally splits.
2) Cut off one of the two limbs (leaving a major, major scar). Which limb?
3) Cut the entire crotch off and top graft, or try to retrain the tree from one of the very low branches I mistakenly left in place a few years ago.

The tree fruits surprisingly well, despite my efforts to thwart it.

They say that you learn by your mistakes.

[orangepippin]

I vote for option 3.

[FB.]

I think you have to cut off the top, below the split.
You might be able to cleft-graft some of its own scions onto what remains (i.e. in the area just below the binding) in order to rebuild the top in the next few years.
If you cleft-graft, do two grafts with a good angle (shape the graftwood appropriately using a knife).

[Glutton4...]

If you wrap something round the branches to protect the bark, you can tie them together higher up, to keep the split closed, and support each other. You can then bandage round and over the split area with something like muslin/hessian sacking strips, to keep any foreign bodies out. You will need to loosen (undo and re-wrap) the bandage, say twice a year, to avoid damaging the tree.

I'm certainly not a tree expert, but have helped do this in the past to the limb of a tree that a customer didn't want to lose. As far as I know it was successful. Although it wasn't a fruit tree. Good luck.

[FB.]

The problem is that there are too many branches originating from one point. Branches need strong anchorage into the trunk and there just isn't room for all of them to be well-anchored into such a small area.
Where branches join the trunk, the grain of the wood changes (a "knot") and too many "knots" in one area make a weak point - and it splits just like your fence panels tend to split near to knots, or, in this case, the tree splits.

It might be possible to do as Glutton4... says, but most of the top branches will have to be cut out completely to allow the others to eventually form a better junction with the top of the trunk.

[yummersetter]

Bite the bullet. Get rid of the mess.It'll always be a problem. Go for #3

[boundtothesoil]

Split crotch resolved

Thanks for the advice. I grasped the nettle as suggested, cut the trunk back to below the split and did three oblique-cleft grafts across the 4 inch diameter.The photos show the dodgy result.



I had never done one of these grafts before and, foolishly, being too impatient, didn't practise it first, hence ran into the following problems:-
1. Not having a special tool for splitting/clefting the trunk (in three places at an angle of about 45o to the edge), I tried to use my grafting knife. Not only couldn't I make the split much deeper than 1.5 cm, but I couldn't wedge it open wide enough to insert the scions easily.
2. Because I couldn't insert the scions deeply enough, matching up the cambiums was difficult and I think I only managed very limited contact.
3. I forgot to make sure that the uppermost bud on the scion was outward facing (still I can cut them back to one if they take), and the general orientation of the scions was inwards not outwards.
4. The clefts didn't close and hold the scions tightly enough.
5. I used grafting wax not only to seal all the surfaces but to secure the scions into the clefts. However, I'd never used wax before (having only grafted onto thin rootstocks etc), and didn't have a good way of either carrying it, keeping it molten or applying it to the wounds. Consequently, the first time I simply poured it on and it just ran down the trunk. By the time I'd sorted this out the stuff had set too stiffly to apply and work gently, causing me to knock two of the scions out of their clefts .

Oh yes, and I cut across the trunk right opposite an old pruning scar, so couldn't insert a scion on the side I really wanted to. All in all I suppose it was what is referred to as 'a learning incident.'

[boundtothesoil]

I thought I'd post an update on this graft - no take on any of the three scions.



They say a bad workman blames his tools. That's me. I definitely didn't have the right tool -a clefting tool. I'm pretty sure that I didn't split the trunk sufficiently deeply, hence couldn't insert the scions properly.

Looking at the lush new growth coming from previously long dormant buds just beneath the cut, I probably needn't have bothered grafting anyway. As FB notes in another thread on this variety, it can be uncharacteristically vigorous. This seems to be the case when grown on MM106 rootstock.

[boundtothesoil]

Nature comes to the rescue?

As a final update on my failed attempt to cleft graft my Ashmead's Kernel, after suffering from a split crotch, in spring 2013, I thought I'd post a sequence of photos, ending on a hopeful note. They may be of use to other members of the 'failed cleft grafters club'.

During early summer, following the failure of the scions to 'take', the tree produced a number of strong new shoots from just beneath the horizontal cut I'd made across the main trunk. They've grown several feet in length in the last few months and could form the basis of a decent framework. However, I'm not sure how many of these shoots to keep. I'm aware that some may have stronger unions with the trunk than others - hence be less liable to split away when larger.

[Bill HH]

Wearing my mechanic's hat, I would have drilled through the split trunk and bolted it together using threaded stainless bar with a plate and nut on either side. I wonder if it would have worked? If it did it would be the first apple tree to have nuts on it.

[seneca196]

on the subject of Ashmeads kernel - what do people make of training it as an espalier? It's widely available on most nursery websites, but never heard it recommended as a suitable variety to train, either as espalier or cordon. Is this down to it's weak and unreliable cropping habit, or is there something else (ie. not freely spurring or compact enough.) I'd be interested in any opinions on the matter.

[boundtothesoil]

on the subject of Ashmeads kernel - what do people make of training it as an espalier? It's widely available on most nursery websites, but never heard it recommended as a suitable variety to train, either as espalier or cordon. Is this down to it's weak and unreliable cropping habit, or is there something else (ie. not freely spurring or compact enough.) I'd be interested in any opinions on the matter.

I think it is due to it being a very vigorous grower (a triploid, see FB's posts on their vigour) ). This is certainly the case when grown as a bush on MM106 rootstock under my soil conditions. The new extension growth can be several feet every year and the internode distance (between successive leaves) is greater than most of the other varieties I grow. This means one doesn't get many fruiting opportunities (i.e. spurs) per foot of stem. Lateral shoot production in general seems a bit on the meagre side. I don't grow any espalier apple trees, but I imagine that keeping the growth of an Ashmead's Kernel in check could be quite challenging.

[seneca196]

So it's unsuitability would be due to the actual espalier form ie. too vigorous so would produce more wooden growth rather than fruiting spurs. In a way, it would need to be enormous for it to produce the expected amount of fruit of a more suitable variety (that would give same amount at half the size.) In terms of space I might be able to accommodate 2 -2.5m height and around 4.5m total width (both sides.) Perhaps that space would give a few more opportunities for spurs, but maybe still only producing a comparatively small amount. That would account for the "poor/weak cropping." So, whilst it is possible to espalier it, it is not the most suitable way to grow it.
I don't have the space for a large tree, so had thought about growing it against a fence, as there is room there. I could have put a cordon in there, but thought this would be more productive. Then again, I wasn't after a bumper harvest, as there's only so many I could eat. This is where it's keeping ability would come in, which along with my cold and not too sunny conditions would work out. Also, it's meant to be a pretty hardy, disease resistant variety. May need to reconsider, but then I had kind of based my plans around it.