- Type
- Herbs & Aromatics
- Difficulty
- Easy
- Season
- Spring
- Sowing
- Transplant
Marsh wormwood
Artemisia selengensis
Essential oils, fibre · the mugwort of wet ground
Marsh wormwood grows in dense stands wherever the ground stays wet, along streams and rice-paddy banks. The part taken as a vegetable is not the leaf but the rhizome: in early spring the soil is opened up and the white, plump underground stems are blanched and dressed. It carries mugwort scent, but far lighter than medicinal mugwort, and the crisp texture comes first, so it is handled like a vegetable in soups and salads alike. The Donguibogam lists it in the Vegetable section as Nuho, glossed in Korean as mulssuk, and calls the taste sweet and pungent, fragrant and crisp to eat. It adds where the plant is found and what it looks like: standing water, resembling mugwort, green with a whitish cast.
Year-Round Calendar
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Where It Grows
- Main producer Known as louhao, it is grown as a spring vegetable along the rivers and lakeshores of Hubei, Jiangxi and Jiangsu.
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Wild population
It grows in dense stands along streamsides, paddy banks and river flats. More of it is dug from wild stands than is planted. Harvest March, April, May
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- Wild population It grows at the water's edge on Honshu and is gathered as a wild green.
- Wild population It is found along the watersides of eastern Siberia and the Amur River basin.
It is native to the watersides of East Asia, from the Korean Peninsula through China and Japan to eastern Siberia. Along the middle and lower Yangtze in China it is a crop in its own right, planted in fields and sold as a spring vegetable; in Korea and Japan it remains mostly a spring green dug from wild waterside stands.
- Optimum
- 15~25℃
- Range
- 5~30℃
- Hardiness
- Hardy
A perennial that grows in dense stands along streamsides and paddy banks, in ground that stays damp. It is cold-hardy, overwintering as rhizomes and sending up its shoots early in spring, ahead of other plants. If the soil dries out the shoots come up thin, and past May the stems turn tough.
Harvested 1–2 years after planting. If you plant divided rhizomes, the first year goes to settling the clumps and harvesting begins the following spring. Once it has taken hold, it comes up in the same place year after year.
In Korea Nationwide
It grows in dense stands where the ground stays damp — streamsides, paddy banks, river flats. From March to May the white rhizomes and young shoots are dug.
How to grow
- Light
- Four hours of sun or more. It survives in part shade but the shoots come thin
- Soil and depth
- Ground that holds moisture. In a pot, stand it in a saucer of water so it never dries out
- Spacing
- 30cm between plants. It spreads in every direction by rhizome, so give it room from the start
- Watering
- It must not dry out. Pots need water daily in summer, and even planted ground needs it in a dry spell
- Feeding
- A spadeful of finished compost in spring is enough. Too much nitrogen makes it leggy and thins the scent
- Harvest
- From March to May, open the soil and lift the white rhizomes; cut young shoots at around 15cm. Never take a whole clump, leave half. Past May the stems go stringy
What makes the difference. Division beats seed. In March or April, cut the white rhizome into 10cm lengths and lay them 5cm deep; they establish the same year
Why this one is harder. Vigour is the problem. Planted loose in the ground it takes over a corner of the plot within a few years. Sink a large bottomless pot, or set a 30cm-deep board barrier around it
Common problems
- Aphids You will see Black aphids packed onto the tips of new shoots What to do Wash them off with a jet of water, and cut shoots often in spring so new growth is not all in one flush
- Mugwort leaf beetle You will see Leaves reduced to lacework, with glossy blue-black beetles on them What to do Hand-pick in the morning. Remove any leaf carrying an egg cluster
- Powdery mildew You will see White dust on the upper leaf surface, spreading outward What to do Thin the clump for airflow and clear away the older lower 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 Donguibogam record — taste and appearance. The Donguibogam lists marsh wormwood in the Vegetable section as Nuho, glossed in Korean as mulssuk. It calls the taste sweet and pungent, and says it eats fragrant and crisp. Made into soup or dressed as a green, it is good either way, and the entry adds that the plant grows in standing water, resembles mugwort, and is green with a whitish cast. This is an old medical record and differs from modern medical judgement.
Analyses of Artemisia essential oils. Analyses of essential oils across Artemisia species report cineole, camphor and thujone detected in different proportions depending on the species and the time of gathering. Marsh wormwood has been measured lower in essential oils than the mugwort used medicinally. This is a record of composition and nothing should be read past it.
Nutrition
- Essential oils (cineole, thujone and others) (the volatiles behind the Artemisia scent) — volatile compounds that carry the aroma
- Dietary fibre (in the rhizomes and young shoots) — fibre that gives the crisp bite
- Polyphenols (chlorogenic acid and others) (commonly reported across Artemisia) — compounds behind astringency and browning
The part eaten is the white rhizome The main ingredient in a marsh wormwood dish is not the leaf but the white rhizome running through the soil. Dig it, wash off the soil, strip the tough outer skin, cut to finger length and blanch. Young shoots are blanched separately; they are more astringent. Because each part needs different handling, they are not mixed in one pot.
The volatile oils The scent of Artemisia comes from volatiles such as cineole and thujone. Marsh wormwood measures lower in these than the mugwort used medicinally, which is why it reads as a vegetable rather than a herb. Being volatile, the aroma leaves with long boiling, so add it to soup at the end. The blanching water carries off astringency along with scent and gets discarded.
Astringency and how to draw it out Freshly dug marsh wormwood is astringent and a little harsh. Two or three minutes in salted boiling water, then half an hour in cold water, takes out most of it. Changing that cold water once helps further. Skip the step and the finish stays muddy no matter how it is dressed.
Pairings
○ Gochujang and vinegar — Once blanched and soaked, it is most often dressed with gochujang, vinegar and a little sugar. The sharp seasoning covers whatever astringency is left. Squeeze the water out by hand before dressing. Chili Pepper (Gochu)
○ Tofu — Blanched marsh wormwood mashed together with tofu turns soft and mild. Press the water out of the tofu first. Season with soup soy sauce rather than salt to keep the colour clean.
○ Pan-fried in batter — Chop it into a thin flour batter and fry it flat. Heat spreads the aroma gently through the pancake. A thick batter kills the crispness, so keep it thin.
△ Toxic plants of the same wet ground — The marshes where marsh wormwood is dug also hold marsh marigold (Caltha palustris) and Japanese buttercup (Ranunculus japonicus). Neither is eaten, and in early spring, judging by shoots alone, they end up in the basket. Marsh marigold has rounded heart-shaped leaves, toothed and glossy; marsh wormwood has deeply cut leaves with white hair underneath. Anything whose leaf shape has not been checked stays in the ground.
△ Strong decoctions and large quantities — Artemisia species contain thujone among other volatile oils, so eating large amounts at once or drinking strong decoctions is not the way to use this plant. Blanched, as one side dish, is the form with a long record behind it. Anyone pregnant or on medication should ask their doctor or pharmacist first.
△ Ditches and paddy banks — The wet ground marsh wormwood likes is also where agricultural chemicals and household runoff collect. Skip ditches below livestock sheds, roadside drains, and paddy banks just after spraying. Setting aside a corner of the plot that stays damp and moving a few plants there means eating only what has a known origin.
Varieties
- Marsh wormwood (division) — Grows at the water's edge. Deeply cut leaves, white underneath; the white rhizome is what gets eaten
- Korean mugwort (division) — The common one. Dry ground, strong scent, used in rice cakes and soups
- Capillary wormwood (injin-ssuk) (division) — Sandy ground, stems persisting through winter. Not dressed as a table green
- Sweet wormwood (gaettong-ssuk) (seed) — Very finely divided leaves and an unusually strong scent. An annual
Source: Donguibogam, Vegetable Section 蔞蒿 · Rural Development Administration (Nongsaro) · Korea National Arboretum species database