Pumpkins

A fruit, botanically, and a large one.

A pumpkin is the fruit of certain Cucurbita species — botanically a fruit, specifically a berry called a pepo, since it develops from the ovary and contains seeds. The culinary classification as a vegetable is about how it is used, not what it is.

Growing

Pumpkins are warm-season annuals needing full sun, rich soil and a long frost-free period. Plants produce separate male and female flowers; the female is identifiable by the small immature fruit at its base. Fruit sets only if pollen moves between them, usually by bees, which is why poor pollination is the most common cause of fruit that starts and then shrivels.

Giant pumpkins

Competition varieties, almost all derived from Atlantic Giant, exceed a tonne. Growers leave a single fruit per plant so all resources go to it, and peak growth can exceed 20 kg a day. At that rate the skin can split if growth outpaces it, which ends the attempt.

The jack-o'-lantern

The tradition is Irish and Scottish and originally used turnips and large beets, carved with faces and lit to ward off spirits at Samhain. Irish immigrants to North America found pumpkins native, larger and far easier to carve, and the pumpkin replaced the turnip. The name comes from a folk tale about a man named Jack condemned to wander with a lit coal.