If there is no actual "Evergreen" tree parts inside of the bag, then it should be good to use with the mix you listed. Is it just the brand name or does it actually have composted evergreen tree inside of it? If you are unsure I'd call the company to ask. Just make sure the manure part is not chicken manure.
yeah Evergreen was the name. However, it also had evergreen flakes, hardwood flakes, chicken and cow manure. I'm going to just go with pure horse manure and mix with other two parts and call it a day lol.
Yeah gonna go with some horse manure, high quality potting soil mixed with it, and then the decayed wood along with the leaves. Probably add in some fish food.
You can feed them fish food occasionally, but don't mix a bunch into the substrate to start things off, that's a really bad idea, you'd get so many mites, and probably too much mold growth for your larva to be comfortable...