hey sorry to hear about your rabbit, im new here as well and im just starting too so ill give you some of the links ive saved.
I have a juniper and just bought a boxwood. I have only taken care of the juniper so far but i build a grow box for it to help the roots and trunk develop, which i would recoment you do as well if you are looking to grow your plants.
This link is about grow boxes. and
here
ok growbox is done now the soil. I was pointed to
this link
Which helped me a lot. I got from lowe the aquatic soil and orchid bark, which is a fir blend. I would say not to use the miracle grow stuff, in order for these trees to develop root systems fast and strong there needs to be good drainage and air in your soil.
Again im new as well, ive just been doing tons of research and saving websites i have found helpfull.
-Mitch aka scumm