Great it passed the scratch-test! Rarely
will that happen in situations such as you started with, VERY rarely
At this point, be VERY careful using any
ferts as it is likely putting out the fine (and super-tender) hairy feeder roots which are super-easy to burn with any type of fert, 'organics' included. There has likely been very little uptake, and if you have not been 'flushing' soil, probably enough there for a little while as tree gets back 'online'. If you do go with 'organics', watch for 'fungus gnats' as they can wreak havoc with root-area (some species anyways) and your mental health, LOL - I *hate* seeing them things crawling around in the soil-mix! Not a huge issue, however.
Do you know specifically what type/species of Juniper it is
? Care can vary a tad with some of them, but at this point its unlikely to really matter, IMO. And dying branches do not 'give energy' into other areas - dead is dead and no sap flows to carry the 'energy' (chemicals within that are generally characterized as 'energy') to other parts of tissue-structures. I am still going to remain a bit pessimistic on this, but optimistically pessimistic
I've had junipers struggle for almost a year before finally giving up the ghost - keep them fingers crossed by all means and do as everyone's been saying, of course. Recovery *will* take a long time, possibly a few years for full vigor to resume. It'd be best to allow it to grow 'wildly' for a few seasons, even putting in-ground for better root re-establishment, IME. If its in a small root-restrictive pot (??), it's as if its being choked as it tries to do its thing. Something to think about there
Fwiw, junipers can take VERY cold temps as long as roots are at least semi-protected, and usually fare better than most species when winter hits harder than usual/expected. Its not like seasons are predictable lately, 'eh?!