Whether you have scale or not, these trees will shed older foliage in the fall. The question is, how to prevent or control that?
In my case, I bought a nice sized hinoki at the National show last September (2018). The tree had been dug/collected in the spring, but looked very healthy and vigorous. I was advised to not do much to it since it was recently collected, so my plan was to just let it be and then either repot or cut back this spring. Then I watched in horror as about a month later (October) a massive amount of the older and interior growth - growth that I was counting on being able to use to build a design - turned yellow and dropped off. I don't know if it was something I did - maybe the tree dried out too much at some point, maybe it should have been cut back sooner - still trying to figure that out.
I did speak to the grower and he said this variety (can't recall which one) will backbud well compared to others, so he recommended wiring out the main branches to allow more light inside. I did that and contemplated repotting or cutting back the existing growth, but chose to do neither. I didn't get any backbudding and now I'm getting another round of fall yellowing (which will lead to foliage dropping) which will push the existing growth even further away from the trunk. So I think I'm going to do a slip-pot to give the roots a little more room to expand, then probably do a hard cut-back next summer and cross my fingers. The other option would be to try grafting foliage further back on those bare branches, but I haven't done much grafting so that might be hit and miss.
I know Sergio (
@MACH5 ) bought a similar hinoki from the same person, and I know he mentioned also losing a bunch of inner growth, but I'm not sure what happened after that. Any updates, Sergio?