Asparagus

• 1. Introduction

  ›

  Asparagus has been on the human menu since at least the 1st century AD, when a Roman cookbook recorded how to cook it. Emperor Augustus himself is said to have used the phrase "faster than cooking asparagus" as a byword for speed. What began as a plant native to Eurasia now fills fields across the world, led by China, which produces 87% of the global harvest. But this common vegetable carries surprising secrets: a medieval nickname so popular it embarrassed the Latin name, a smell scientists only began tracing in 1891, and a variety developed in Italy that turns from purple to green on the stove. How did a feathery perennial plant from the coasts of Europe become one of the world's most cultivated vegetables, and what does it mean that eating it changes how our bodies smell? Those are the threads this documentary follows.

• 2. The Name and the Plant

  ›

  John Walker wrote in 1791 that "Sparrowgrass is so general that asparagus has an air of stiffness and pedantry." The folk corruption of the plant's name into "sparrow grass" was so widespread that the classical Latin term felt almost foreign to ordinary speakers. The name itself traces back through Medieval Latin "sparagus" to the Greek "aspáragos," whose provenance remains uncertain. One proposal links it to a Proto-Indo-European root meaning "to jerk, scatter," possibly arriving via a Persian word meaning "twig, branch." Another possibility is that the Ancient Greek word, which meant "gully, chasm," is simply Pre-Greek in origin. The nickname "sparrow grass" persisted in rural East Anglia well into the twentieth century.

  Physically, the plant that hides behind these names is a feathery perennial. Its stems can grow as tall as 3.5 m, with needle-like structures called cladodes, which are modified stems rather than true leaves, ranging from 6 to 32 mm long and just 1 mm broad. These cladodes cluster together in groups of up to fifteen, arranged in a rose-like shape. The flowers are small, bell-shaped, and greenish-white to yellowish, measuring 4.5 to 6.5 mm long. The plant is usually dioecious, meaning male and female flowers grow on separate plants, though hermaphrodite flowers do sometimes appear. The fruit is a small red berry, and it is toxic to humans.

• 3. Cultivation and Varieties

  ›

  Asparagus has an unusual relationship with salt. Because it originates in maritime habitats, it thrives in soils too saline for most weeds, and gardeners traditionally added a little salt to asparagus beds to keep weeds down. The drawback is that salted soil cannot support other crops. Crowns, as the root systems are called, go into the ground in winter, and the first shoots emerge in spring. Those first pickings are known as sprue asparagus, identifiable by their thin stems.

  Purple asparagus, originally developed near the Italian city of Albenga and sold under the variety name "Violetto d'Albenga," differs from green and white types in having high sugar and low fibre levels. It can turn green when cooked, because heat affects its pigment. In early 2011, a UK grower announced an early-season variety that can be harvested two months ahead of the normal schedule. Unlike standard asparagus, this breed does not need to lie dormant; it blooms at 7 degrees Celsius rather than the usual 9 degrees Celsius.

  White asparagus is created not by breeding but by technique. As the shoots grow, soil is mounded over them so they receive no sunlight. Without photosynthesis, the shoots stay white. In Germany, where white asparagus is sold as "white gold" or "edible ivory" and called "the royal vegetable," the season traditionally ends on the 24th of June. During this Spargelsaison, roadside stands and open-air markets account for roughly half the country's consumption of white asparagus.

• 4. History at the Table

  ›

  A recipe for asparagus appears in De re coquinaria, a collection compiled by the writer known as Apicius in the 1st century AD, making it one of the oldest surviving culinary records. In the 2nd century AD, the Greek physician Galen described asparagus as a beneficial herb. When Roman influence faded, written mentions of asparagus faded with it, though the plant remained popular in the Byzantine Empire.

  Asparagus crossed the Atlantic with European settlers by at least 1655. Adriaen van der Donck, a Dutch immigrant to the colony of New Netherlant, included asparagus in his account of Dutch farming in the New World. In 1685, William Penn listed asparagus among the crops thriving in Pennsylvania in an advertisement aimed at prospective settlers. The French court also held asparagus in high regard: the pointed tips, called "love tips" or points d'amour, were served as a delicacy to Madame de Pompadour, who lived from 1721 to 1764.

  In Europe today, the UK asparagus season traditionally opens on the 23rd of April and closes on Midsummer Day. Asparagus dishes are advertised outside restaurants from late April to June. The French style favours boiling or steaming and serving with Hollandaise sauce, white sauce, or melted butter. Dedicated tall, narrow pots let the shoots be steamed with their tips above the water. In Cantonese restaurants in the United States, asparagus is often stir-fried with chicken, shrimp, or beef.

• 5. The Smell

  ›

  Louis Lemery noted in his 1702 Treatise of All Sorts of Foods that asparagus causes "a powerful and disagreeable smell in the urine, as everybody knows." John Arbuthnot, writing in 1735, observed that the effect was especially strong when asparagus was cut while still white. Marcel Proust, who lived from 1871 to 1922, offered a more colourful verdict: asparagus "transforms my chamber-pot into a flask of perfume."

  The first systematic investigation of the smell came in 1891, when a researcher named Marceli Nencki attributed it to methanethiol. Later science confirmed a broader set of culprits: the sulfur-containing compounds produced when the body digests asparagusic acid include methanethiol, dimethyl sulfide, dimethyl disulfide, bis(methylthio)methane, dimethyl sulfoxide, and dimethyl sulfone. Because asparagusic acid and its derivatives are the only sulfur compounds unique to asparagus, they are considered the source. Young asparagus contains more of these compounds, which matches the long-standing observation that the smell is stronger after eating younger shoots.

  The smell appears quickly and fades slowly. It can be detected as soon as 15 to 30 minutes after eating, and it declines with a half-life of roughly four hours. Interestingly, the link between asparagus and odorous urine was not widely noted until the late 17th century, when sulfur-rich fertilisers began to be used in agriculture. Studies have found that somewhere between 40% and 79% of people produce the characteristic smell, but among those who do not seem to, some may simply lack the ability to detect it. The difference in detection traces to a single-nucleotide polymorphism in a cluster of olfactory receptors.

• 6. Global Harvest and Celebration

  ›

  World production of asparagus reached 8.6 million tonnes in 2023, with China supplying 87% of that total. The scale of Chinese production has shifted asparagus from seasonal luxury to year-round import commodity. In Europe, high local prices during the short growing season reflect strong demand and limited supply, but imports are also common.

  In the western Himalayan regions of Nepal and north-western India, a plant called Ornithogalum pyrenaicum is harvested as a wild seasonal delicacy. Known locally as kurilo or jhijhirkani, it is called "wild asparagus" though it is a distinct species.

  Communities that grow asparagus tend to celebrate it. Oceana County in Michigan, which calls itself the asparagus capital of the world, hosts an annual festival. The Vale of Evesham in Worcestershire, which makes the same claim for Britain, holds an annual British Asparagus Festival, including auctions of the best crop, an "Asparagus Run" modelled on the Beaujolais Run, and a weekend music event called Asparafest. In Germany, many cities hold an annual Spargelfest for the white asparagus harvest. Schwetzingen, Germany, also claims the title of Asparagus Capital of the World. The contest over that title, spread across three countries, says something about how deeply this plant has rooted itself in local identities.