Pumpkins are actually a type of winter squash, with a hard rind.
They are a warm season crop, and usually need about three to four months of warm growing days with temperatures above 75 degrees to set fruit and grow to a large size, according to Ross Penhallegon, horticulture agent with the Oregon State University Extension Service. To grow a giant pumpkin, you will need to select a pumpkin variety with the potential to grow to a large size. This variety regularly tops 200 pounds, says Nichol's seed catalog. Plant your pumpkin seeds after the danger of frost has passed and the soil is thoroughly warm. Or start your seeds indoors and transplant outside when the soil warms up above 55 degrees.