|Growing Pumpkins (source)
When to Plant
Most varieties will take between 85 - 125 days to mature. The larger variety of pumpkin, usually will take the longest time to mature.
Choose a full sun location with 20-30 feet for the vines to grow. Your site also should have good drainage.
Try working some compost into the area where you'll be planting your pumpkins. This will create a nice, rich soil bed.
Plant your seeds 1 - 2 inches deep. Germination usually takes place within 7 - 10 days, and once they do, add a little bit more compost around your seedling. This will help keep weeds down and help to retain moisture.
When the stem starts to twist and dry, or the shell has started to harden, it's most likely time to harvest. Try piercing the shell of the pumpkin with your fingernail. If the shell is hard, your pumpkin is ready to cut from the vine. Leave about 3 inches of the stem on the pumpkin when removing it from the vine.