Miracle grow is ok. I use 10-10-10 on all my plants and epson salt for magnesium. Bananas need a fertilizer high in nitrogen

You probably shouldn't fertilize with granular at this point, it should be done earlier in the spring if at all because you don't want less hardy new growth going into winter. I use organics. I use a combo of chicken manure and Espoma plan-tone. Liquid I used fish emulsion, along with liquid kelp when I planted. Miracle grow won't hurt them fertilizer wise, but I believe in organic ferts.

Peach-wise, I just asked the same question but I only discussed organics. I was told Captain jack's dead bug is good in the summer, dormant oil in the winter.