Common Name: Water Spinach, Kangkong, River Spinach, Water Morning Glory, Ong Choy, Water Convolvulus, Swamp Cabbage
Scientific Name: Ipomoea aquatica
Family: Convolvulaceae (the Morning Glory or Bindweed family)
Common Names (I did the best I could considering I speak none of these languages!):
- Bengali = kalmi shaak or kalami
- Burmese = gazun ywet or kan-swun
- Cantonese (Jyutping) = weng cai or tung coi or ong tsoi or ung coi (sometimes transliterated as ong choy)
- Chinese (Mandarin) = kōng xīn cài or toongsin tsai
- Chinese (Hokkien) = eng ca
- Dutch = waterspinazie
- Filipino and Tagalog = kangkóng or cancong
- Hindi = kalmua or kalmi or kalmisaag
- Japanese = asagaona or ensai or kankon or kuushin sai or stuu sai
- Khmer (in Cambodia) = trâkuön
- Korean = kong sim chae or da yeon chae
- Laotian = pak bong or bongz
- Malay and Indonesian = kangkung or ballel
- Thai = phak bung or pak hung or phak thotyot
- Vietnamese = rau muống
Description:
My first experience with this plant was in the Asian supermarkets while I was living in Minnesota. I was very curious about it, but it took many trips before I got up the nerve to sample the bright green leaves. I had no idea what the vegetable was called, but it was quite good. It came as no surprise when I heard it called Water Spinach, as it really does taste like “regular” spinach; althought Water Spinach has a bit nuttier taste.
While the plants I normally highlight on this site are perennial and well suited to cool or cold climates, I do make exceptions for exceptional plants, and Water Spinach (or Kangkong) is one of them. It is common in Southeast Asia and grows with almost no care in many waterways. Unfortunately, because it grows so easily, it has been named an “invasive” in many parts of the United States. In warmer locations, it can be grown as a perennial. In cool to cold locations, it can be grown as an annual or as a greenhouse plant. It grows so fast and easily, and tastes so good, that I think everyone in a Temperate Climate should be growing this plant indoors in the Winters and outside in the Summers.
History:
Botanists are unsure where Water Spinach originated, but it likely came from somewhere in eastern India to Southeast Asia. It was first documented in 304 AD with the Chin Dynasty in China. Currently it is found throughout tropical and subtropical regions around the world, but is a common ingredient in Southeast Asian cuisine.
Trivia:
- Water Spinach (Ipomoea aquatica) is closely related to Sweet Potatoes (Ipomoea batatas) and Common Morning Glories (Ipomoea purpurea)
- Water Spinach has two major forms: Red-Stemmed (with pink to purple flowers) and White-Stemmed (with white flowers).
- White-Stemmed Water Spinach as a number of cultivars that can roughly be categorized as long-leaf (or narrow-leaf), broad-leaf, white-stemmed (pak quat), green-stemmed (ching quat), etc. There is no formal classification that I can find.
- Some consider the white-stemmed variety (pak quat) of the white-stemmed form as better tasting than others.
- There is growing research showing that the red-stemmed form has more health benefits.
- Each variety and cultivar has different culture characteristics as well… some can grow in moist soil, while others need to grow in water, and some can grow in both conditions.
- Water Spinach grows fast… up to 4 inches (10 cm) in a day!
- Water Spinach stems are hollow and can float.
- Water Spinach will root at the nodes on the stem, and these roots can establish new plants if the stems break.
- Water Spinach usually likes full sun, but can be a great herbaceous groundcover in very hot locations.
- Water Spinach is considered an invasive weed in the United States. But almost no one is eating it!
USING THIS PLANT
- Edible Shoots – typically only the young and tender shoots are eaten, usually cooked.
- Edible Stems – typically only the young and tender stems are eaten, usually cooked. These stems are hollow and are crunchy when cooked. The stems require only a little bit longer cooking time than the leaves.
- Edible Leaves – can be eated raw or cooked (stir-fried, sauteed, boiled, parboiled, etc.). The older leaves are more fibrous and are generally avoided. The leaves are used much like “regular” spinach in Western cuisines, but there are many Asian recipes that look delicious…
- Recipes (I don’t normally list recipes, but since many Westerners are unfamiliar with this plant, I thought it would be a fun idea):
Secondary Uses:
- General insect (especially bees) nectar plant
- Ornamental Plant – beautiful flowers
- Animal Fodder – older leaves and fibrous stems are used as animal feed in tropical climates. But in any area where this plant is growing too fast, it would make a great ancillary feed source.
- Biomass Plant – the fast growing nature of this plant could allow it to be harvested and used as mulch or in compost
Yield: Variable.
Harvesting: Best harvested before flowering. Often harvested 30-60 days after sowing, depending on climate and culture – earlier if fully aquatic and later if semi-aquatic. Water Spinach can be harvested completely or in a cut-and-come-back-again manner – secondary shoots will form and grow. Harvest in the coolest part of the day to prevent moisture loss and wilting.
Storage: Water Spinach is very perishable… it does not store well. It only stores well in the refrigerator for about a day, but occasionally can make it 2-3 days. This is why we should grow our own!
DESIGNING WITH THIS PLANT
AHS Heat Zone: 12-6
Chill Requirement: Unlikely, but no reliable information is available.
Plant Type: Aquatic or Wetland Plant
Leaf Type: Perennial in warm climates. Annual or greenhouse plant in colder climates.
Forest Garden Use: Aquatic/Wetland Layer, Herbaceous Layer, Groundcover Layer
Cultivars/Varieties: There are a number of varieties available for this plant.
Pollination: Self-fertile
Flowering: Warmer months (usually Summer)
Life Span: No good information available. Considering that the plants grow so fast and can be propagated from cuttings so easily, an individual’s life span is likely irrelevant.
PHYSICAL CHARACTERISTICS OF THIS PLANT
Roots: Fibrous. Stems can root at the nodes.
Growth Rate: Very fast
GROWING CONDITIONS FOR THIS PLANT
Shade: Tolerates light shade
Moisture: Moist to wet soils or fully aquatic conditions (still or flowing waters)
pH: 5.5-7.0 (but it can tolerate a wide range of soil conditions)
Special Considerations for Growing:
- If you live in a warmer climate, consider the fast-growing nature of this plant.
- Since this is an aquatic or semi-aquatic plant, there is always the question of how to grow it in water. Briefly, the seedling or rooted cutting is placed in very wet soil. This can be “puddled soil” like a rice paddy or at the pond’s edge or in a floating island (like Geoff Lawton) and allowed to grow into the water from there. See Propagation section below.
Propagation:
Can be grown from seed, often soaked for 24 hours before sowing. Can be easily propagated from cuttings just below a node; Water Spinach freely roots at the node. One source explains that commercial operations will take cuttings approximately 12 inches (30 cm) in length (which will have 7-8 nodes) and plant them 6-7.5 inches (15-20 cm) deep.
Maintenance:
Minimal. You may need to keep it from spreading too much if you live in warmer locations. Harvesting for human and/or animal consumption is the best method, by far!
Concerns:
- When eaten raw in Southeast Asia, there is a chance it can carry the parasite Fasciolopsis buski, the largest intestinal fluke in humans… it is best to cook it if in this area of the world!
- Listed as an Invasive in many places, especially in the United States. It is illegal in some parts of the United States to even be in possession of it! Please check with your local state laws!
Photo References:
- http://www.payer.de/amarakosa/amara02760.jpg
- http://upload.wikimedia.org/wikipedia/commons/4/49/Ipomoea_aquatica.jpg
- http://ppcdn.500px.org/7390354/1063ffb474cc139f6d212a214bc6a2ab8acf47a0/5.jpg
- http://upload.wikimedia.org/wikipedia/commons/c/c3/Ipomoea_aquatica_Nksw_1.jpg
- http://upload.wikimedia.org/wikipedia/commons/f/f1/Starr_080530-4636_Ipomoea_aquatica.jpg
- http://farm1.staticflickr.com/171/418033533_e2804ad31a_o.jpg
- http://www.lushplants.com.au/~lushplan/images/stories/virtuemart/product/kang-kong-ipomoea-aquatica.jpg
- http://www.flickr.com/photos/manggy/2620247365/sizes/l/in/photostream/
- http://farm9.staticflickr.com/8026/7385708312_df5c9346af_o.jpg
- http://www.clovegarden.com/ingred/img/mg_ongwat01g.jpg
- http://www.ecofilms.com.au/wp-content/uploads/2014/01/Permaculture-Fish-Pond-2.jpg
- http://2.bp.blogspot.com/-dUbFZXFOcGk/T6PA59E9kYI/AAAAAAAAAOg/DI3YPQJvYZ4/s1600/IMG_0720.JPG
- http://www.worldngayon.com/wp-content/uploads/2012/07/DSC_0331.jpg
- http://lifestyle.inquirer.net/files/2012/05/t0531louie-cruz_feat2_2.jpg
- http://blog.seasonwithspice.com/2012/05/malaysian-sambal-belacan-kangkung.html
This plant is very invasive and is on the USA Federal invasive species list. If it gets a chance to go feral, it will croud out native species and do a lot of damage to the ecosystem. For as interesting and useful as it is, it should never be introduced into a new area and doing so in the US is illegal.
Water spinach is not listed as a noxious plant in Idaho. Possibly because the climate limits its growth to the point where it wouldn’t survive outside beyond summer. Interestingly though, water chestnut is listed as a noxious weed, so must have an ongoing presence. I wondered if this is the same water chestnut that can be bought in cans for Chinese stir fry. If so, I might look for places where it is invasively growing anyway to harvest some. Any chance you might add water chestnut to your list (with all the caveats about not introducing it)?
This would be a great plant to grow in Aquaponics in a temperate area so it wouldn’t be invasive. Many people say autumn olive is invasive and it is back east with rainy summers but it is not here in the west with dry summers.
John S
PDX OR
Paul – I’m not sure where you got your information but here in the Free-State of Texas we settled this issue back in 2009. It is legal to purchase and grow it for personal consumption and to grow it commercially with permit. Now – I just need to find some.
Try going to a Houston or Dallas Asian market & grab a bunch from the produce dept. It is truly easy to sprout (much like those house ivy). Just don’t buy seeds online from EBay. Texas department of Ag. will absolutely come confiscate).
can you send cutting through the mail? it says it is cultivated in my state but i cant find any. i also cant find a source for seeds of the different varieties if you have any info it would be helpful
ebay sells seed of several different kinds.
& can Paul please tell us where it’s become invasive? I think I should like to move to that town. Seems like we could harvest all this unwanted food & distribute it amongst the impoverished. There is no excuse to waste a known food source. If one has enough knowledge to research the status of a plant, they should have enough knowledge to research palatable ways to prepare it for consumption…
Try using it in the Filipino dish sinagong. It is the best Filipino food!
I’ve been growing this in pots in the arid zone for about three years. It’s so prolific and such a beautiful and versatile plant. I pick it daily for our chickens to eat (they love it), and my family eats it all the time. I’m cultivating more now to sell/swap with other local gardeners. In our winters it dies back, but comes back to life in spring.
Thanks for this interesting article!
I was wondering how much of the chickens diet is the water chestnut? Chickens might be in my future & I love the idea that I can grow what they eat!
The plant on the US invasive species list is the
European water chestnut Trapa natans L.
http://www.invasivespeciesinfo.gov/aquatics/waterchestnut.shtml
The plant we are talking about here is the
Asian water chestnut Ipomea aquatica.
That being said I still believe care should be taken to contain this plant since it isn’t native to the US.
Thanks for the article!
We use this vegetable in alot of different ways
In Sinigang (Tamarind soup) or stir fry with some garlic and a little soy sauce
This vegetable is also great steamed and served with some shrimp paste. There are lots of recipes online you for this delicious nutritious vegetable
This is a very tasty vegetable used in Thai and other Asian cuisine. Stir fried with garlic and soy/oyster sauce is my favourite. I was also interested in it’s potential use as a water purifier and found this research from Vietnam, which, given the culinary uses, would make it preferable to Water hyacinth in reed beds! “The role of aquatic plants and microorganisms in domestic wastewater treatment” (https://www.scopus.com/record/display.uri?eid=2-s2.0-84926334368&origin=inward&txGid=ddaadc5e2dda8e4aef2fd7ec419ba58c)