Required Vigor for KGB Pruning/Training

Last year I planted some tart cherries somewhat close to my house, so I would like to suppress a good deal of their vigor going forward. For what I can see, the Kym Green Bush (KGB) method should work well with vigorous trees (http://msue.anr.msu.edu/uploads/resources/pdfs/Cherry_Training_Systems_(E3247).pdf ). I have a Montmorency on “Standard” rootstock (probably Mazzard), which I think would do well with this system. However, I also have a Meteor tart cherry on K7 (~90% of Mazzard)… but Meteor is naturally a semidwarf. Would that be too little vigor for system like KGB?

Any other suggestions for training systems to limit the size of these trees? The trees were planted as large whips last year and headed at 3 feet (yes, that is high for KGB, but it was not part of the plan then). There are several branches now on each tree with narrow crotch angles (despite my efforts to spread the branches).

Does Montmorency have a different growing habit than other tart cherries have? Montmorency is not grown here. But most tart cherries I know have a rather dropping growing habit. I have difficulties to imagine KGB working for that. It would be difficult to establish those vertical shoots able to carry high yields. Maybe the spanish bush system is more apropriate for that?

I am very fine with a simple spindle tree with my tart cherries. I have some young apricot seedlings I try to train to KGB. First flower buds on them might develop this season.

No, you should adjust the amount of fruiting wood. The Gisela videos on KGB go into it a touch more. With dwarfing rootstock you can reduce the amount of fruiting branches With sweet cherry on Gisela 5 you want about 20 upright fruiting branches, with Mazzard maybe 30. So decrease fruiting wood to maintain vigor on dwarfing rootstocks.

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@carot This is my first experience with tart cherries, so the general habit is not clear to me. Between the two varieties, the shoots are very different (going into second leaf). Meteor has a only a few strong shoots that have narrow crotch angles but then start to broaden as they rise- perhaps these branches will eventually droop. Montmorency is quite the opposite: many weaker shoots with a wide crotch angle that turns upward after several inches of lateral growth.

I admit that I glossed over the information on the Spanish Bush system. I will give it a second look for sure.

@Drew51 Thanks for the video Drew. That was one of the videos that helped me think KGB may be appropriate for what I want. You make a good point about limiting the number of shoots. With a pretty vigorous rootstock and not-so vigorous tree, I may have to spend a few years to find the right balance.

Yes, like medicine it’s a practice. Spellman in his last DWN video mentions one never stops pruning and that is true. I’m finding that for me about 20 shoots is not enough, my sweet cherry is on Gisela 5 I was out there today looking at my trees and thinking about pruning. I want to do the large pruning cuts while I can see the structure well, but most will be done once growing as it seems the safest way.

For those utilizing KGB, do you get lateral shoots on the uprights? What do you do with them?

I topped some of the longer shoots from last season and this spring there are 2-3 shoots from those tips. Generally 1-2 of each are at wide angles to the upright. As I understand it, there aren’t laterals on KGB, so do I use thinning cuts? Wouldn’t it be a Spanish bush if i stub them back?

I gave up on the KGB method before I got started. I did not give it a fair chance.

Yes, well they keep the laterals. You can have too many branches, and I think that is why they remove them. It depends on rootstock the number of branches. I started my tree with this system, but altered it as I wanted to change part of the tree to another cultivar. I can still do it, I graft the stubs, but next time I will have to leave enough not to remove the graft. Which is five years away I’ll worry about it then.