I put wayyyy too much Hollytone on my red hybrid this summer and it shed all its leaves, then put on the most amazing flowering display all over the branches I’ve ever seen, and then all the flowers fell off. My leaves still haven’t grown back but the branches always stayed green and now there’s tiny new buds forming. After realizing I put too much fert I drenched it trying to leach out any excess fert that was in there. Not sure if it helped or not but the tree is starting to bounce back. Good luck!