Trunk chop-Multiple vs one large chop

[crab apple]

I see ppl talking about chopping multiple times over the years instead of just waiting for your desired trunk size and just chopping once, I can see the benefit of not doing one large chop with the scaring and everything but just in an effort to get the procedure down correctly, when doing the multiple chop method are you still chopping as low as you would if you would have done a single chop later? and are subsequent chops ever below an earlier chop or are you really just doing the exact same cutts but doing them earlier in the trees development? I'm not really talking about pines. I know they are different but mostly asking about deciduous trees.

 

[Shibui]

First need to remember that most of this is aimed at deciduous trees that sprout well on bare wood. Need a modified version when developing conifers and species that don't bud well on bare wood.

Everybody will have their own favourite methods but the way I do it is make the first chop quite low - probably around where I would like the first branch to be on the trunk but there's no real spot for the first chop. First chop could be 1-3 years old depending how thick/big I plan to make the tree and how fast it has grown.

As a result of that first chop I get 3-6 new shoots all growing up from the stump. I let those grow as tall as they can in one year then assess next winter. One of these new trunks will give a better trunk line than the others so chop the spares right down to the trunk and shorten the chosen one a few nodes higher than the original chop. You'll now have a much thicker base and a reasonable thickness new section so you already have some taper and hopefully a nice bend.

Next spring more new shoots will emerge from around the cuts where you removed the surplus trunks and from the new chosen extension. Let them all grow as tall as they can for a year and assess in winter as before, removing less attractive lines and keeping another short section above the previous chop. The base should be thicker again, the second section will also have thickened and now should taper nicely into the base. The new section is a but thinner than previous sections so even more taper as the height increases.

Continue for as many years as needed to get the desired trunk thickness.

Move the tree into a grow pot to reduce growth a little while growing the next few sections of trunk. You may also be able to start developing some branches now but beware of keeping long internodes as they defeat good ramification. Reduced growth rates allows the previous sections to merge reducing obvious shoulders at chops. It also develops new sections with shorter internodes so branching toward the top of the tree will be closer together to make the apex.

At some stage you can prune new leaders a couple of times through summer to reduce new sections even more and promote more ramification and branching.
With strong growing species you may need to transplant to a bonsai pot to control strong growth and long internodes in the final stages.

Through that method I end up with trunks that have already healed most of the earlier chops. If done well I get great taper in the trunks and nice bends which reduces the years needed after chop to get all those things.

Usually subsequent chops are a bit above the previous because that helps with the taper and trunk bends but occasionally I'll find a much better new trunk line through one of the new shoots in which case I will chop lower. The downside of chopping lower is we lose some of the trunk taper and have a much bigger 'shoulder' that needs time to merge the thinner new section into the thicker lower section but that just means a couple more years of grow and chop to rectify.