of 1.1 Ton Pumpkin (Time lapse video)

One thing they do is removing all the other flowers, so the plant puts everything into one fruit. I think the grower also tries to develop roots on the arms of the plant, so they help a bit putting them back into the ground. You also see in the vid that they use sand to support the pumkins weight a bit. The tent is there to protect the pumpkin from sunburn. It also looks like they start very early in the growing season, using a heater to protect from the cold at night. (and many other things...)