Monitor the nighttime temperatures to see if they go below freezing. The prime picking time is after the first couple of frosts.
Notice the color and the firmness of the pumpkin. It should be bright orange and hard.
Knock the pumpkin. If it sounds hollow, the pumpkin is ready to be picked.
Inspect the stock at the stem of the pumpkin. It should be woody and hard.
Put the pumpkin in a greenhouse or in the house for two or three days to cure it. Pumpkins will last for three or four months.