scource the seed as a starter, from a known giant variety if possible. Start them off in a frost free place, plant out when all danger of frost has gone into very well manured rich soil which must be matured. Watering & feeding are then essential to achieve as big a pumpkin as possible. Reduce the fruit to one or two young pumpkins per plant. I have actually heard some years ago that someone intraveniously fed a sugar/solution directly into the stem of the fruit in order to super-boost growth ??? Sounds horrible & not entirely sure this is'nt some urban horticultural myth. Mindyou, I would'nt want to mess with the competition growers, I value my green fingers & want them to stay firmly stuck to my hands ;-)) Good luck & I'm pretty sure there will be some excellent tips popping up here for your perusal.