Rich orange pumpkins are a mainstay of fall traditions. They sit on porches and windowsills as temperatures drop, keeping the last of the summer sunlight within their bronzed rinds. However, white pumpkins are carving out their own niche as an eye-catching novelty. Their ghostly pale rind stands out among their orange brethren, adding interest to standard displays. Because their rinds remain white, however, you may have difficulty knowing when these pumpkins ripen.
Keep track of your planting dates, and tuck the original seed packet into your planting journal or tape the empty packet to a fall month on your calendar. The seed packet has a "Days to Harvest" number, and knowing this time window gives you a general time frame to expect ripe pumpkins. When this ripening window rolls around, start checking your white pumpkins for cues to harvest. The popular Casper pumpkin generally ripens in 105 days.
Pumpkin vines don't age gracefully. As the pumpkins ripen, the vines lose their green color and become dry and woody. Watch the pumpkin leaves and vines for wilting, drying and age-related decline. Light frosts usually wilt any remaining leaves but do not harm a ripe pumpkin. Hard frosts, however, may damage your pale pumpkins. If the forecast calls for a hard freeze, harvest the pumpkins. Always leave 2 to 6 inches of stem.
Your thumbnail can give you a good idea of a white pumpkin's harvest readiness. Press your thumbnail against the rind. If the rind is hard and difficult to cut, the pumpkin is ripe and ready to add to your fall display. If the rind gives under your thumbnail or cuts easily, give the plant more time. Sunlight also helps harden a rind. Carefully rotate the pumpkin to expose all sides and to prevent soft spots.
If your white pumpkin is close to harvest but a hard frost threatens, go ahead and harvest it. Place it in a sunny spot to ripen fully, rotating it as needed. Once ripe, white pumpkins are edible, but they are not as sweet or rich-tasting as pie pumpkins. If you choose to save your white pumpkin's seeds for next year, keep in mind that pumpkins cross-pollinate, and your seeds may produce orange pumpkins.