Some pumpkins are ready to be harvested. According to Iowa State University Extension and Outreach, pumpkins can be picked when they have developed a uniform, deep orange color and the rind is hard or they can be left until the vines are killed by a light frost or freeze. It is recommended to leave several inches of a stem attached to each pumpkin, as they are less likely to rot.
To cure a pumpkin, put them at a temperature of 80 to 85 degrees and 80 percent relative humidity for 10 days to help harden their skins. Also, when storing pumpkins, place them in a single layer with space for air circulation to slow the growth of fungi and bacteria that may result in rot.