Ume grow strongly, but tend to have the most viable buds out toward the tips of branches. That tends to make trunk-chopping nerve-wracking. Coupled with the relatively limited information about timing and severity of chopping, and it’s a dicey proposition.
Here is an Ume seedling I bought from Brent back in 2009ish as a pencil-thick trunk. It’s been in the ground for 7 years, but not in a prime spot, so it’s been slowish. I dug it in 2015 and moved it to an Anderson flat for the big move. Without a dedicated spot to ground-grow trees, I just set them on the ground and roots have escaped.
Anyway, I wanted to tidy up Ume had grown to about 6′ and I really wanted a bud somewhere low on the next section. Playing it safe again, I left some low branches, but trimmed each back to a leaf or two, and chopped the trunk down to about 10″
Here is a bad shot of the sacrifice leader:
3 buds to choose from! Of course, I want the lowest on, both to compact the trunk, and to add more movement. Difficult to see, but I did reduce the trunk to the lowest of the three buds, this photo taken 2 months after the initial chop in May: