SiNguyen

Hi Jersanct, I have a couple of questions:
1. When was it collected or dug up from the ground?
2. When was its root last chopped before you repotted it?
3. What did you use in your soil mix?
4. How do you know that you removed only half of the rootage if you left the other half of the root ball in the old clay dirt? (There might not be any root in that old dirt ball in the beginning).
5. How much did you fertilize it?
These questions might help you decide on what to do next.

To me, you have 2 options:
1. Do nothing more. Just put in shade, water very little, and do not fertilize any more for a long time. Just wait and see.

2. Do everything now. Defoliate, remove all soil, wash and prune roots to clean healthy edges, place in airy 100% inorganic mix like pumice, use rooting hormone or Willow water, add mycorrhiza, mist tree, and do not fertilize for at least a year or more. This is what I would do. Your chances are 50/50 I think.

If you had used a commercial potting mix (like from Homedepot or garden centers) or if you had fertilized it too strongly, then you should remove the soil now (Option #2). The commercial potting mix frequently have added manure for fertilizer. New roots can't take too much nitrogen. Leaving your tree in this soil will just kill it slowly. Most of the roots would be dead by now anyway, so repotting it won't do any more harm. If your tree is already in a very loose well-drained soil mix, then you could possibly soak and wash the fertilizer out of the root ball, but you don't seem to have that.

One possibility is that you might have effectively removed most or all of the good roots when you repotted it six weeks ago. Eventhough you had left some of the old clay dirt attached, this old portion might not have any small feeder roots in it. It still might recover if this is the case, but you will have to reduce foliage to match root strength.

Another possibility, and a very likely one, is that the tree was dying all along, ever since it was first dug up (if this was recent and if they did not potted it up correctly). These junipers can take a long time to look dead, up to a year even. Even when it was pushing out the last few buds, it was on its last sap of energy. People who collects alot of junipers from the wild can vouch for this.

If only the old foliage was turning brown, and not this year's new growth, then the tree would probably be OK, then you don't have to do anything more (option 1).

When the foliage looks like what you have, then the roots must be damaged (ie. overwatered, root fungus, root rot, too much fertilizer, too much roots removed, etc). You just have to decide how bad the roots are and how much you have to do to correct it.

You only need one or two live branch on this tree to style it anyway. So don't worry too much about how it will look, as long it is still alive somewhere. Good luck!
Si