A Roman emperor wheeled his cucumbers into the sun every day
Tiberius wanted cucumbers at every meal, winter included. According to Pliny the Elder, his gardeners planted them in raised beds mounted on wheels, rolled them out into full sunshine, then pulled them back under frames glazed with a clear stone, probably sheet mica. It was an early greenhouse built for one man's salad.
The plant behind that obsession, Cucumis sativus, was domesticated in India from a wild variety called hardwickii, and has been farmed for at least 3,000 years. Its native range runs from India, Nepal and Bangladesh through southern China into northern Thailand. East Asian types split off from Indian ones around 2,500 years ago, and Greeks or Romans probably carried it west. Charlemagne grew it in his gardens; England got it in the early 1300s, lost it, and had to reintroduce it about 250 years later. Columbus's Spanish expedition brought it to Haiti in 1494, and by 1535 Jacques Cartier saw "very great cucumbers" at the site of present-day Montreal.
Botanically, a cucumber is a pepo, a kind of berry with a rind, even though cooks treat it as a vegetable. It is 95% water, and 100 grams supply just 16 kilocalories, with vitamin K the only nutrient present in any notable amount. The faint melon scent comes from aldehydes such as 2-nonenal, while bitterness in the peel comes from cucurbitacins, compounds that may help fend off insects and other grazers.
Growing them depends heavily on insects. Most seeded varieties cannot fertilise themselves and need pollen from another plant, so thousands of honeybee hives are trucked into fields just before flowering each year. Older varieties open male flowers first and then roughly equal numbers of female ones; modern gynoecious hybrids bear almost only female blossoms, though temperature swings can still coax out a few males. Seedless greenhouse types set fruit without pollination, and those long, thin-skinned "burpless" cucumbers, up to 60 cm, are often sold shrink-wrapped.
Gherkins are simply small cucumbers, 2.5 to 12.5 cm long, named from an early modern Dutch word for a little pickled one. China dominates the crop today, growing 78% of the 88 million tonnes of cucumbers and gherkins harvested in 2024. In Thai kitchens even the shoots get eaten, often with crab meat sauce.
Source: Cucumber
