The last time I have ghts, I had 20 trees to plant. Dug the holes and dropped in some in each hole (luckly had got 10 eyes the day before and another 10 the morning of.) Otherwise it goes In my grass clipping pile. I live out in the country.
Thought I would give an update with a lesson learned. Was mowing the lawn this weekend when I notice that 10 or so of the trees I had place the fish carcases under appeared to have been incorrectly packed. They had what looked like sink holes. Upon going back and trying to fill them in, it was not in fact from piss poor compaction, but a mental issue of the planter. A (or multiple) coons decided they wanted the remains more than I thought the trees needed them. I had buried the remains 18-24 inches deep.
So I do NOT recommend placing these under seedlings. Maybe a big balled trees. I don't know if the trees that had the vermin issues will survive.