- Type
- Leafy Greens
- Difficulty
- Easy
- Season
- Spring
- Sowing
- From rhizome
Japanese bindweed
Calystegia pubescens
Calystegines and starch · a pink trumpet vine over the field bank
Japanese bindweed is a common perennial vine of field banks, open ground and river levees. Pale pink trumpet flowers open through the middle of the day, and the leaves are long and arrow-shaped. Morning glory opens at dawn and fades by midday; bindweed stays open through the day, so the hour of flowering alone separates them. The young spring shoot is blanched and dressed as a green, and the white rhizome running underground was steamed and eaten. The Donguibogam lists it in the Herb section as 旋花 and records the Korean name as metggot, describing a climbing habit, leaves like Chinese yam but narrower and longer, and flowers of red and white. The root has no hairs or joints, the entry adds, and is worth steaming and tastes sweet — a line that says plainly it was famine food. Once it enters a plot, though, it comes back however often it is pulled, and the original text says the same: nothing is harder to weed out.
Year-Round Calendar
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 3
- 4
- 4
- 5
- 10
Where It Grows
-
Wild population
Common nationwide on field banks, paddy banks, riverbanks, and roadsides. Harvest April, May, October
- 4
- 5
- 10
- Wild population Grows widely in fields and along waterways in the central and northeastern regions.
- Wild population Common in fields and on embankments from Honshu to Kyushu.
Because this plant grows wild in the temperate fields of East Asia and no commercial production statistics exist, the table below is divided into three rows by countries with wild populations rather than by output. Hedge bindweed (Calystegia sepium), similar in name and appearance, is a different species spread widely across Eurasia and North America, so this map shows only the distribution of Japanese bindweed (Calystegia pubescens), the East Asian species.
- Optimum
- 18~28℃
- Range
- 5~35℃
- Hardiness
- Hardy
This is a perennial climbing vine found in sunny fields and on embankments. It overwinters via its underground rhizomes and comes up again the following spring, and because it tolerates heat and drought well, it keeps sending out vines all through summer. It is not fussy about soil, and once it takes hold it does not give ground easily.
Harvested 1–2 years after planting. If rhizomes are buried in March–April, the vines run and young shoots can be picked from that very year, but rhizomes thick enough to be worth digging come from plants that have grown for a year or two. Being a perennial, it comes up again the following year even if only a fragment of rhizome remains.
In Korea Nationwide
This is a plant gathered from where it grows wild rather than planted and raised. The young shoots are picked in April–May, before the vines start to run, and the white rhizomes spreading underground are dug in October, once the leaves have withered. Because it is hard to clear out once it gets into a field, in home gardens it is planted confined in a large pot.
How to grow
- Light
- Full sun. It will run in shade but flowers sparsely
- Soil and depth
- Not fussy, though soft, stone-free ground is better if you mean to dig the rhizome
- Spacing
- 50cm or more between plants, and always fix the boundary with a pot or a barrier. The rhizome travels a long way underground
- Watering
- It manages without watering. Watch it only through the first summer
- Feeding
- No feeding. Rich ground only gives more vine to deal with
- Harvest
- Pick young shoots in April and May while they are still soft, before the vine runs. Dig the rhizome in October once the leaves have died back
What makes the difference. Blanch the shoots and rinse them in cold water; peel the rhizome and steam it through. Neither is eaten raw
Why this one is harder. The real difficulty is not growing it but stopping it. A fragment of rhizome is enough to bring it back, and once it is in a plot it is hard to clear. The Donguibogam text says the same: nothing is harder to weed out. In a small plot, put it in a large pot from the start
Common problems
- Aphids You will see They mass on vine tips and flower buds What to do Wash them off with a jet of water. Use nothing on plants whose shoots you will pick
- Leaf beetles You will see Holes and grazed patches across the leaves What to do Pick them off as you see them. The vine is vigorous enough to grow through ordinary damage
- Powdery mildew You will see A white dust settles on the leaves after the rainy season What to do Thin the vine for airflow and remove affected leaves
This page describes how a crop is grown and used. It does not claim health effects for any food, nor is it intended to prevent or treat disease. Component and study notes are references only and do not mean the same result occurs in people. Consult a medical professional about health concerns.
Health Benefits
The old record — seonhwa (旋花). The Donguibogam lists the plant in its Herb section as 旋花 and gives the Korean name as metggot. It records a warm nature, a sweet taste and no toxicity. Another name, 鼔子花, is explained by the flower's resemblance to a drum, and the flowers are picked in the fifth lunar month and dried in the shade. It describes a climbing habit, leaves like Chinese yam but narrower and longer, flowers of red and white, and a root without hairs or joints that is worth steaming and tastes sweet. It grows in fields, is found everywhere, and is the hardest thing to weed out. What an old medical text wrote differs from how it is judged today.
Calystegines of the bindweed family. Alkaloids called calystegines were isolated from the genus Calystegia, and the genus name became the name of the compound. Analyses report them widely across the bindweed family. These are compositional analyses.
Told apart by the hour of flowering. Bindweed stays open through the middle of the day; morning glory opens at dawn and fades by midday. Separating the two vines by flowering time is a standard field observation. This is a record of behaviour.
Nutrition
- Calystegines (distributed in the rhizome and shoots) — a group of alkaloids first isolated from the genus Calystegia, which gave them their name
- Starch (stored in the thick rhizome) — the compound behind the faint sweetness when it is steamed
- Dietary fibre (present in shoots and rhizome) — the fibre behind the stringy texture
Starch in the rhizome The white rhizome running underground stores starch. Steamed, it has a faint sweetness, and it appears across the records as famine food. The Donguibogam likewise notes the root is worth steaming and tastes sweet.
Alkaloids of the bindweed family Alkaloids called calystegines were isolated from the genus Calystegia, and the genus name became the name of the compound. Analyses report them widely across the bindweed family. This entry stays with the compositional record, and it is the reason the plant is cooked and eaten only as a side dish.
Preparing the young shoot Blanch the young shoots in boiling water, rinse in cold and dress. Throw the blanching water away. Once the vine has run out long the shoots are too tough to use.
Never raw Both the shoot and the rhizome are cooked. Wash the rhizome, peel it and steam it thoroughly. Undercooked, a harsh note stays.
Pairings
○ Steamed with a pinch of salt — Peel the rhizome, steam it through and salt it lightly. The faint sweetness comes forward. It is drier than potato or sweet potato, so serve something with liquid alongside.
○ Dressed with doenjang — Dress the blanched shoots with doenjang. The flavour is mild, so a little garlic is needed to give it an edge.
○ Mixed with stronger spring greens — Too mild to carry a dish alone. It was used mixed with more aromatic spring greens to stretch the amount.
△ Eating it raw — Neither the shoot nor the rhizome is eaten raw. Alkaloids called calystegines are reported in the genus, so the plant is blanched or steamed through and eaten only as a side dish. Do not juice it or chew it raw.
△ No seed from any bindweed family vine — Morning glory seed, from the same family, was long handled separately and is not eaten as food. Morning glory and ivyleaf morning glory routinely grow mixed in with bindweed, so no seed of any of them is eaten. What is eaten is the young shoot and the white rhizome, nothing else.
△ Where you dig — Do not dig on plot banks, paddy edges or roadsides, where herbicide may have been sprayed. Bindweed is treated as a field weed and is sprayed directly more often than most plants. Dig the rhizome only where last year's vine and flowering position can be confirmed.
Varieties
- Japanese bindweed (rhizome) — The commonest species. Pale pink flowers open at midday
- Hedge bindweed (Calystegia sepium) (rhizome) — Larger in leaf and flower, found on levees and in rough grass
- Aegimekkot (Calystegia hederacea) (rhizome) — A smaller species whose leaf base flares out to either side
- Sea bindweed (Calystegia soldanella) (rhizome) — A coastal species of sand, with thick round leaves
Source: Donguibogam, Herb Section 旋花 · Korea National Arboretum, Korean Plant Names Index