Trident Maple Help

I did an emergency repot after getting this back from a friend who was caring for it whil I was away. Help?? What's happening and how do I fix it?

It is called repot stress. It happens more or less to any tree that is repotted. The best way to minimize It includes repotting in the right time of the year and only repot perfectly healthy trees. It seems like you got panic and failed on both.

I do not think that you were awai long enough for the soil to degrade to the point where repotting got urgent or that your friend changed soil when you were away. 

Good aftercare after repotting can limit the problem. It includes shaded position and focus on watering.

What made you think it needed to be re potted so urgently? If it was not stressed before it is now. Keep it out of the sun and watered well, and hope you have not killed it. It may lose all leaves and then come back, it may wait until next year.

I apologize for not expounding further. She had given it osmocote and the high nitrogen was burning the leaves and stunting growth. I tried simply rinsing the salts out, but that didn’t work. I knew I needed to get the osmocote out.  While it pushed new growth at first, the same heavy leaf burn happened. I could see what I thought were signs of root rot, the blackening on the branches. After examining the roots, I could see the root ball was caked full of clay. They couldn’t breath and were staying wet. While the outer soil appeared dry the inner was staying soggy. I did clean the caked clay from the roots when repotting. Those pictures were from several days ago. It has lost a couple branches completely since. I wanted to know if it appeared to be fungal as well? If so, would a hydrogen peroxide soak help? 

The soil in the rootball was like clay, and it couldn’t breath. It wasn’t drying out at all.

Osmacote is a slow release fertiliser and unlikely to cause leaf burn, more likely it was dry at some point which will show leaf damage quite quickly. High nitrogen will not stunt growth, in fact the opposite would happen. You could have improved drainage by making holes in the soil and the re potted at the appropriate time, as in the heat we have had this year it has caused severe stress now and will take a long time to recover. No hydrogen peroxide will not help.