[Offwego]

I've got a builders ton bag full of manure ready for next year,it's well rotted. My question is could I direct plant a pumpkin in it?

Simply trying to make it look more tidy

[LotuSeed]

Absolutely!

[New shoot]

I'd use just a bit of MP compost in the planting holes to bed them in, plant one each side and let them trail over.  You will need to keep them watered.  It is surprising how even a big bag of stuff like that dries out once the plants get going