Cabbage and kin

Wild cabbage is a plant of sea cliffs. It is a perennial with a bare, woody stem, a tuft of waxy blue-green leaves and tall stalks of yellow flowers, and it is said to live for ten years or more.12,11 It grows on limestone and chalk along the Atlantic coasts of Spain, France and Britain, in small colonies cut off from one another.36,12,11

It has close relatives around the Mediterranean, most of them cliff plants too. Brassica cretica grows on Crete and the coasts of Greece. Others are confined to Sicily, to Corsica, or to one mountain range in Cyprus. 56,125756,58,5756,5756,57

All of them share the crops' 18 chromosomes, and all can be crossed with the crops. 56,126,36 That makes it hard to say which one the crops came from.

For a long time the Atlantic cliff plant was taken to be the ancestor. Genetics has shaken that. A 2021 study of 224 plants found the crops closest to Brassica cretica of the Aegean, and concluded that they were domesticated once, in the eastern Mediterranean. The Atlantic plants looked like escaped crops. 4,94,1,54,11,10

Others disagree. A 2023 study argues that B. cretica only seems close because the crops have bred back into it. A 2022 study sees two lines of domestication, with kales perhaps carried east from Atlantic Europe. 4,94,1,559,4

Hard evidence is thin. Leaves do not survive in the ground, and Brassica seeds are hard to tell apart. 55,60 The oldest seed claimed for the species is a single burned one from Tell Tweini in Syria, about 3,200 years old.22,4

The plant enters writing as a word. Greek poets of the 6th century BCE swore oaths by the krambē.1,7 It is missing from the older vegetable lists of Egypt and Mesopotamia.1

Theophrastus, born about 370 BCE, described three kinds: curly-leaved, smooth-leaved and wild.37,7,5,37 In Rome, about 160 BCE, Cato listed much the same three and declared that cabbage "surpasses all other vegetables". 23,2523,5 These are leafy plants. The Greek texts record no head at all.5

By the 1st century CE there was more variety. Columella named a dozen Italian towns for their cabbages, and Pliny described seven kinds, some with a large "head". 24,525,5 Whether those were true cabbages cannot be settled from his words.5,1

Kale, cabbage, kohlrabi, broccoli, cauliflower and Brussels sprouts are one species. They cross freely and their offspring are fertile.1,2

What differs is the part of the plant that was enlarged. In kale it is the leaves. In cabbage it is the bud at the tip of the stem, folded into a head. In Brussels sprouts it is the buds along the side. In kohlrabi it is the stem itself, and in broccoli and cauliflower it is the flower head.1,2,3

In 1821 the botanist De Candolle sorted the whole species into six races by form, the first formal scheme in the sources cited here.33

No single gene has yet been shown to make any of these shapes. A mutation long tied to the cauliflower's head also turns up in kale and in wild plants. 6338,64,65,1038,10

One form grew up far from the others. Chinese kale is the only crop of the species that took shape in Asia.4,54

A Chinese study of old texts and pictures, as later authors report it, concluded that the plant reached China around the 5th to 6th centuries CE and was reshaped in Guangdong. No archaeological find supports this, and we have not read the study itself.19,4

Its place in the family is unsettled. One genetic study makes it the sister of all the other crops. Another ties it to broccoli and cauliflower, and a third reads it as a hybrid.4,38

In medieval northern Europe the cole in the pot was still mostly leaves. Cooking pots from England, 750 to 850 years old, are reported to hold wax from its boiled leaves.4

The head has a word of its own. Medieval Latin caputium, from caput, head, gave English cabbage, French cabus and German Kappes. It has no Greek ancestor.1

The first clear description we have read is from 1542. Leonhart Fuchs pictured a kind whose leaves fold into a head, and said people in Bavaria ate it daily.28 By 1570 the Low Countries grew white and red cabbage in bulk and shipped it to Germany, England and Spain.8,16 In the same years a looser, more tender kind had a new name: Savoy.8,16

Cauliflower and broccoli are flower heads, eaten before they bloom.1,2,3

A farming book from 12th-century Seville describes a "Syrian cabbage" of two kinds, one compact and one branching. Its translator took it for cauliflower. 2929 The sure records come later. In 1570–71 Lobel described a foreign cabbage with dense white clusters, called Cauliflore in Italian. Others named it the Cyprus cabbage. 830,31

Broccoli is harder to pin down, because the word first meant the tender shoots of any cole, as eaten around Naples.16 It was new to England about 1720.18

Which came first? A 2024 genome study has cauliflower bred from broccoli, by way of Romanesco. Other studies find separate origins, or a hybrid one.9,53,1

In 1554 Mattioli described a cabbage in Italian gardens whose stem swells like a turnip. He could find no earlier writer who mentioned it.17,18 Lobel, in 1570–71, called it a foreign plant that had come from the Greeks, and saw it at Florence and Padua.8,16 A list of plants for Charlemagne's estates has a word, ravacaulos, that means turnip-cabbage, but nothing shows it was this plant.68,69,18

Brussels sprouts are the last to appear. In 1587 Dalechamps pictured a rare cabbage with many heads, which may or may not be one.31,33 The first certain account is from 1821, when De Candolle wrote that it was "very commonly cultivated" in Belgium.33

The forms traveled with European ships. Kale is reported from Virginia in 1669.18 In 1672 John Josselyn listed the English garden plants that did well in New England, and put cabbage first: it "growes there exceeding well".34

Cabbage also traveled pickled. James Cook carried "Sour Krout" in quantity on the Resolution, served a pound to each man twice a week, and judged it "highly antiscorbutic". Whether it really kept scurvy away cannot be shown, because he used other remedies too. 7071,70

Japan is said to have received leafy kinds in the Edo period and head cabbage at the start of the Meiji era. It took decades to enter Japanese cooking. 7273

On Jersey a giant kale grew stems so long that islanders made them into walking sticks, 30,000 a year by one account. 33,18

In 1935 the species was fitted into a larger pattern, known as the Triangle of U. Three species, among them Brassica oleracea and the turnip's species B. rapa, crossed in pairs to give three more. Rapeseed is the child of those two. 76,77,7879

The genome of a cabbage was read in 2014.13,14 Every main form has been sequenced since, and the family tree has grown less tidy, not more.64,38 Kale is not one branch but several, near the root.6,4,38,39 Cabbage, collards and Brussels sprouts sit together.4,6,38,9 Kohlrabi lands somewhere different in each study.38,4

One reason is that the forms never stopped crossing with each other.38,4 The tree on this page shows the best-supported lines of descent, and most of them are drawn dashed or dotted for that reason.

Modern breeding began with an oddity: these plants mostly cannot fertilize themselves. Breeders, chiefly in Japan, turned that into a way of making uniform hybrid seed, and one Japanese seed company says it announced the first hybrid cabbage in 1940. 11,8072

Color came by chance. Orange cauliflower and purple cauliflower each go back to a mutation in a single gene.66,67

Taste was pursued on purpose. In the 1990s researchers at a Dutch seed firm showed that two compounds make Brussels sprouts bitter, and that people object only above a threshold. 35,3535 Breeders were by then selecting milder sprouts with the help of taste panels.81

Broccoli's rise is recent too. The supply of fresh broccoli in the United States was half a pound a person in 1970 and six and a half pounds in 2020.82

The world grew 75 million metric tons of what FAO counts as cabbages in 2024, and another 27 million metric tons of cauliflower and broccoli. 1515 China and India grow most of both.15

The cabbage figure needs care. It appears to take in Chinese cabbage and pak choi as well, which belong to another species, Brassica rapa. 83,1579

Tastes keep shifting. In the United States the supply of cabbage has fallen since 2000, while that of Brussels sprouts has risen about fivefold since 2010. 8282 In the highlands of Kenya a tall leafy kind, sukuma wiki, is the most important leaf vegetable.84

It is still one species, and gardeners are still changing it. 1,281