Turnips
In the Western world, the turnip (Brassica rapa) is best known as a root vegetable. However, in China and Asia, Brassica rapa was bred into many different vegetables, giving rise to leafy, heading, and oilseed varieties, as well as other root varieties. These plants are less commonly cultivated here, but are excellent crops for our region, especially the Northwest Coast.
As with many other crops that were domesticated early on by humans, the exact origins of Brassica rapa are uncertain, but it appears to have been native to Central Asia and the nearby Himalayan Mountains. From there, the domesticated plant was taken both east and west, where it was separately developed into the many varieties we have today.
Note on taxonomy
The taxonomy for the various cultivated varieties of turnips (as well as other Brassicaceae family plants, such as coles, rayas, rutabagas, and other mustards, is still somewhat murky and under considerable debate. There is still a lot of uncertainty about these plants, but fortuntaely, ongoing genetic analysis is providing more and more answers over time.
Because of the current situation, I’ve opted to avoid using cultivar group names and to focus on arranging information about the mustard family based on how they’re used, and how they were developed historically or regionally. I will update these articles as research provides more clarity.
Species and varieties
Turnips
Turnip (Brassica rapa)
Root selections
European turnips
Nabiza
Japanese turnips
Pan choy
Leaf selections
Chinese turnip greens
Bok choy
Tat choy
Napa cabbages
Mizuna
‘Mibuna’
‘Komatsuna’
Stem selections
Rapini and grelos
Yu choy
Seed selections
European rapeseed
Chinese rapeseed
Indian rapeseed (sarson)
Yellow sarson
Brown sarson
Toria sarson
Root selections
These turnips, selected for their enlarged storage roots, are the best-known type in the US.
Root turnips are among the oldest turnip varieties. European, Chinese, and Tibetan turnips all share genetic similarity; those from Japan appear to have a slightly different origin and are derived from Afghan turnips. Root turnips were a common food in both ancient Rome and China, but European and Asian varieties were mostly bred separately from each other.
Most root turnips have globe-shaped roots, but there are also turnips with longer roots. The leaves from all root turnip varieties are also perfectly edible. There are varieties with white, purple, red, and yellow skin. Many turnip roots develop green or purple tops where they come in contact with the sun while growing.
As with others species in the Brassica genus, turnips are a cool weather crop that dislikes warm soil and tends to bolt in summer. Their flavor deteriorates with summer weather. They can be planted for two growing seasons; either harvested in late spring, when they reach a usable size, or planted in fall. Turnip roots are an excellent fall crop that can be pulled and stored over winter. There are some varieties that can also make it through winter in the Northwest Coast region.
European turnips were grown primarily for their roots and were often selected for their storage qualities. There is a fair amount of genetic similarity between Chinese, Tibetan, and European turnips, but the exact relationship between these is still uncertain.
In northern Spain and Portugal, tender, small turnip greens, known as “nabizas” (Spain) or “nabiças” (Portgual), are also harvested.
Japanese turnips tend to have smaller taproots and have a different leaf structure than European turnips, but are otherwise similar. Many of the smaller varieties are excellent eaten raw.
The “pancai” (or “pan choy” if going by Cantonese pronunciation) is an ancient root cultivar that produces large, squat turnips roots with a very mild flavor.
Leaf selections
Often called “Chinese cabbages” in English, these related turnip varieties are excellent crops for our region. Selected for their leaves and stalks, they grow negligible storage roots.
Fast-growing, they can, depending on the exact variety, be harvested from mid-spring into summer or planted for a fall or winter harvest. Most varieties overwinter successfully in the Northwest Coast region.
Chinese turnip greens
Bok choy is a leafy turnip green with enlarged petioles (lower stalks, basically). The name we use in the US is derived from the Cantonese name for the vegetable, meaning “white vegetable”. Bok choy is sold in a range of sizes and there are numerous varieties, with white, green, and dwarf forms.
Tat choy, also known as “tatsoi” and “rosette bok choy”, is a winter-hardy green that has thinner leaf stalks than bok choy but is otherwise very similar. It grows in a flatter and more open form than bok choy. I prefer to use the name “tat choy” to stay consistent with other Cantonese-derived vegetable names.
Napa cabbage
The napa cabbage appears to have been created by crossing a Chinese leaf turnip with a Chinese root turnip. Napa cabbage is the turnip equivalent of heading colewort, cabbage, having been selected for its ability to form a tight bundle of leaves. Also known as “dai bok choy” (big bok choy). The name “napa cabbage” comes from the Japanese word “nappa”, meaning “leafy vegetable”. They’re commonly grown in Japan, Korea, and northern China, especially for fermenting. There are green and purple varieties.
Napa cabbages do best as fall crops in the Northwest Coast. They can be pulled in late fall and stored in winter. Although they can handle some amount of freezing temperatures, they’re not as cold-hardy as cole cabbages.
Mizuna
Mizuna are a sizable group of winter-hardy turnip green varieties from Japan with serrated leaves and a peppery flavor.
These greens appear to be more closely related to oilseed turnip varieties from India and Japanese root turnips rather than other Asian turnip greens.
The leaf stalks are not as emphasized as on Chinese leaf turnips. Mizuna is often incorrectly labeled as a variety of Brassica juncea. Mizunas usually have white stalks and green leaves but many purple varieties also exist.
‘Mibuna’ is a Japanese variety that looks like komatsuna, but with more slender leaves.
‘Komatsuna’ turnip greens are Japanese leaf turnip varieties with spoon-shaped green leaves and thin stalks.
Stem selections
These turnip varieties were bred specifically for their flowering stems.
They are the equivalent to gai lan, broccoli, and broccolini, which are cole shoots from the Brassica oleracea plant.
The leaves, flower buds, and enlarged stems are eaten for their pronounced bitter flavor. Rapini are popular in Italy and in northern Spain and Portugal, where they are known as “grelos”. These varieties were developed from European root turnips, independently from Asian varieties.
They’re often referred to as “broccoli rabe” in the US; unfortunately, this name can cause confusion as to what the plant is. The name broccoli rabe is an invented marketing name derived from “broccoli di rapa”, Italian for “little turnip shoots”. The other Italian name often used is “cime di rapa”, or “turnip tops”.
Rapini can be harvested in both spring and fall, and are fairly cold-hardy in the Northwest Coast region.
Yu choy, meaning “oil vegetable”, is the Chinese counterpart to European rapini and grelos, developed from Chinese turnip green varieties. This turnip shoot variety was likewise selected for its enlarged stems, small leaves, and flower buds. It is less bitter than rapini, but it still has a pronounced mustard flavor.
Yu choy is also widely called “choy sum” or “yu choy sum” in English. “Choy sum” means “vegetable heart” in Cantonese and it’s a general term that refers to the flowering stem of any mustard, cole, or turnip, not just yu choy.
Other turnip shoots
All turnips varieties will eventually bolt and attempt to flower and go to seed. The resulting flowering shoots that appear can be harvested and eaten.
The most common of these of these are bok choy shoots, known as “bok choy sum”, but napa cabbage shoots, tat choy shoots, and so forth are all fair game.
Seed selections
The turnip has been cultivated since ancient times to produce oil from its seeds.
Turnips were selected for oil production in three separate regions: Europe, China, and India. These are known in English as “turnip rape”. The seeds are known as “rapeseed”. This unfortunate name is also used for the oilseeds of several other mustard species, but today mostly refers to Brassica napus varieties, which have supplanted the turnip varieties in many places. See the article on rutabagas for more information.
In India, Brassica rapa was selected primarily to produce oil. Brassica rapa oilseed is an important commercial crop there, where it is known as “sarson”. Recent studies indicated that there are three distinct subspecies of sarson: yellow sarson, brown sarson, and toria sarson.
In addition to their use as oil crops, sarsons are also cultivated for their leafy greens, especially in the north of India, where they are a common cool-season crop. Interestingly, sarsons appear to be closely related to Japanese mizunas.
