when to dig ground for pumpkins help please

When the ground is thawed out and not too claggy to dig is about the right time to add manure etc .

I tend to just spread it on the top of the soil right now and let the worms help out with incorpoarting it into  the soil. 

Hlepful little devils, worms 

I would fork it in as blackbirds have a habit of throwing your muck about as they search for food so it gets disturbed as will your plants as the muck gets flung far and wide. I found this to my cost when all my bean and pumpkin plants got grubbed up and they died on the surface. So, next time I made sure that I covered the muck with soil to hide the manure. I patted it down with the back of the spade too 

OK THANKS