What I did in the fall was this : I made a pit and mixed the soil with a mixture of dried cow/chicken manure(pellets), mulched
birch leaves and grass, that's all.
I thought the "chicken part" could be too strong but not so. I have a small empty chicken coop since february(fox!)
in which I seeded some "normal" pumpkins with not much hope of success because it was really a layer of chicken manure
on the ground. But two plants made it and they are really exploding now. I have 3 pumpkins bigger than a basketball and
one already stopped growing, so pumpkin soup in august?
Just to say you can't predict what is the best at that particular
place with that particular soil and that particular fertilizer, and then I'm not even mentioning wheather conditions.
Now I think I simply will go with the 16-9-20 fertilizer (disolvable in water) I already have and see what happens.
Thanks for the advice guys!