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Food

In Chinese, water spinach is ‘empty heart vegetable.’ Here’s the story behind the name.

Nov 06, 2019

Chinese water spinach, sometimes called morning glory, is used in all sorts of dishes across Asia. But in the West, it’s considered a weed.

“What the Plant?” is Clarissa’s weekly column where she dives into the origins, legends, and misconceptions surrounding some of the most beloved ingredients in Chinese cuisine. First up is Ipomoea aquatica, better known in the West as Chinese water spinach.


If you grew up in Asia—or have had some exposure to its food—you’ve most definitely encountered the Chinese water spinach, sometimes called morning glory.

A long, crunchy vegetable with a hollow stem, it’s usually served as a side dish, draped with a blanket of minced garlic, water, a pinch of salt, and a touch of umami (usually from MSG).

Chinese water spinach stir-fried with chili and shrimp paste. (Yes, that is a plate shaped like a shovel.)
Chinese water spinach stir-fried with chili and shrimp paste. (Yes, that is a plate shaped like a shovel.) / Photo: Xiaomei Chen/SCMP

In Southeast Asia, where the vegetable is most prevalent, the simple garlic and water slurry is elevated with chili, shrimp paste, and fermented bean sauce.

Despite its name, the Chinese water spinach is not actually a spinach.

Despite its name, Chinese water spinach is not actually a spinach. It’s not even in the same plant family, and the misnomer might be the fault of grocers, who tend to assign the word to anything miscellaneously leafy and green.

(Read more: Like the avocado, this expensive vegetable has become a symbol of bougieness in China)

The Chinese water spinach, or Ipomoea aquatica, is part of the morning glory genus, called so because of their trumpet-shaped flowers that peak at full bloom in the morning.

The flower of Ipomoea aquatica, or morning glory.
The flower of Ipomoea aquatica, or morning glory. / Photo: Shutterstock

But when it comes to the Chinese water spinach, the stem is the main attraction.

The stalks are thick, hollow, crunchy things that are great at absorbing flavor. As a kid, I would spend evenings with my mom kneeled over a colander full of spinach to pick out the most tender stems.

In Chinese, its name comes from a tragic love story

I know water spinach by the Chinese name kongxincai 空心菜, which literally means “empty heart vegetable.”

The poetic moniker comes from a 16th-century fable about a government minister who is forced to gouge out his heart after one of the king’s wives tires of his advice.

The poetic moniker comes from a 16th-century fable about a government minister who is forced to gouge out his heart after one of the king’s wives tires of his advice. His tomb notably had just one single plant growing: the kongxincai, or empty heart vegetable.

(Read more: All tea, whether it’s green, black, or oolong, comes from the same plant)

Historical records going back to the Ming Dynasty (1368-1644) say the vegetable came to China by way of tropical Southeast Asia, where it’s known as kang kong, or swamp cabbage, because it can grow on both land and water.

Some farmers plant it directly in wet soil; others choose to let the hollow stems float on top of nutrient-rich ponds.

Chinese water spinach growing in a pond.
Chinese water spinach growing in a pond. / Photo: Shutterstock

Another Chinese name for the vegetable is 蕹菜, pronounced ong choy in Cantonese, and it comes from this method of raising the plants.

The first character 蕹 refers to the simple propagation technique: taking a cutting and packing the bottom of the stem in moist soil.

But in the West, it’s considered a weed

Europeans records of the Chinese water spinach date back as early as the 16th century, and in particular, they note the plant’s extreme productivity.

(Read more: We picked and ate some wild plants in Hong Kong’s countryside)

Under optimal conditions, it can produce up to 84 tons of food per acre in nine months, growing at a rate of 4 inches per day.

That’s great if you need a lot of food, less so if you’re trying to keep your land clear.

The state of Florida banned the cultivation of Chinese water spinach because it began spreading across ponds.

In 1973, the state of Florida banned the cultivation of Chinese water spinach, which had been brought in as a non-native food crop, because it began spreading across ponds, clogging waterways, and obstructing boats.

Federal regulators then classified it as a noxious weed, and to this day, some states still prohibit the sale of Chinese water spinach, while others have allowed farmers to grow them only with permits.

In 2003, 90% of commercial water spinach in the United States was grown in northern California, according to a Portland State University report.

Chinese water spinach on sale at a market in Thailand.
Chinese water spinach on sale at a market in Thailand. / Photo: Shutterstock

In Asia, the water spinach is far from demonized, and in Asian supermarkets across the States, it remains an irreplaceable grocery item. Some communities where it’s banned are even willing to smuggle them in.

Because a weed, after all, is in the eye of the beholder, and the Chinese water spinach has been overlooked for its most redeeming quality: a food source that grows indefinitely in wet environments, and a tasty perennial that keeps on giving.

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