My pumpkin fruits are blossoming, but they reach the size of a 'golf ball' and then they dry up and die out. There's been several pumpkin fruits of this same vine in the past 2 months where this mishap has occurred up to the present day. Is there something I am not doing right with my pumpkin plant, watering, or soil maintenance? Also, it's my first time growing a pumpkin plant. Also, I have this same pumpkin plant growing in with other vegetable plants in the same row. Any tips? 