- Type
- Herbs & Aromatics
- Difficulty
- Hard
- Season
- Spring
- Sowing
- Division
Korean Epimedium
Epimedium koreanum
Icariin · three branches, nine leaves
Korean epimedium is a perennial of the shaded mountain woodland floor. The Korean name comes straight from the form — the stem divides into three, and each division carries three leaflets, nine in all. The leafy stems have long been picked in spring and dried for tea or steeped in liquor, and herb markets sell them under the name eumyanggwak. Icariin, a glycoside, was isolated from the leaves and now serves as its marker compound. Long collection has made it scarce in the wild, so a plant found on a hillside is better left where it stands. The Donguibogam lists it in the Herb section as eumyanggwak (淫羊藿), also called seonryeongbi (仙靈脾), and notes that people commonly call it samjigu-yeopcho, the three-branch nine-leaf herb. It records a warm nature, with a note that some call it neutral, a pungent taste, with a note that some call it sweet, and no toxicity. It sets down the form — growing in hills and fields, leaves like apricot leaves, a stem like a millet stalk — and records picking the leaves in the fifth lunar month to dry in the sun, grading highest those grown where the sound of water cannot be heard.
Year-Round Calendar
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Where It Grows
- Main producer The plant known in Korean as samjiguyeopcho (Epimedium koreanum) grows wild in the mountains of Jilin and Liaoning, where it is harvested as a medicinal herb. Most of what is traded in China as eumyanggwak, however, is other species such as E. brevicornu and E. sagittatum.
- Wild population It grows wild under the broadleaf forests of northern Gyeonggi and Gangwon. Long years of digging have reduced its wild habitats.
- Wild population The same species grows wild in the mountains of northern Honshu and Hokkaido.
The species' range is the northern temperate forest zone stretching across the central and northern Korean Peninsula, northeastern China, and northern Japan. Since no single country can be named as its place of origin, we have not included an origin row. What circulates in markets under the name eumyanggwak (yin yang huo, the herbal name for epimedium) is a mix of several species, so when shading it on a map the species must be specified.
- Optimum
- 15~22℃
- Range
- 5~28℃
- Hardiness
- Hardy
It grows beneath broadleaf forests in mountains where summers stay cool. It handles winter cold well, overwintering — surviving the winter — through its roots, but direct midday sun and summer heat scorch its leaf tips. The best sites are in partial shade where fallen leaves pile up and hold moisture.
Harvested 2–3 years after planting. In the first year after divided clumps are planted, no leaves are picked. Plants take a couple of years to settle in, and from then on the leafy stems are harvested each year in May–June.
In Korea Mountain areas
Its known wild habitats lie beneath broadleaf forests in the limestone country of northern Gyeonggi and Gangwon. The clumps persist only in partial shade where summers are cool and leaf litter builds up thick.
How to grow
- Light
- Part shade that closes over in summer. Midday sun straight on the leaves scorches them
- Soil and depth
- Free-draining soil with leaf mould worked in, at least 25cm deep. Mix grit and leaf mould together
- Spacing
- 25 to 30cm between plants. The rhizomes run sideways and fill the space within a few years
- Watering
- Water when the surface dries. Left dry in summer the leaf tips scorch
- Feeding
- A thin mulch of leaf mould in early spring and again in autumn. Keep chemical fertiliser light
- Harvest
- May and June. Cut the leafy stems at the base once the leaves have opened fully but not yet thickened. Take no more than half the leaves from a plant. The old text records picking the leaves in the fifth lunar month and drying them in the sun
What makes the difference. Dry the cut stems spread in a breezy shaded spot. Anything stored damp goes mouldy, so seal them only once fully dry
Why this one is harder. Long collection has made this plant scarce in the wild. Do not dig one from a hillside; buy a nursery-raised division instead. Even then it takes two or three seasons to settle, so take no leaves in the first year
Common problems
- Slugs You will see Holes in the new spring leaves What to do Collect them by hand in the evening and ring the plant with diatomaceous earth
- Leaf scorch You will see Leaf tips brown, starting where midday sun reaches them What to do Shade the position or move the plant. Cut off the scorched leaves
- Root rot You will see Shoots fail to appear in spring, or start and then wilt What to do Mix in grit and raise the bed so water does not sit. Dig out rotted crowns and do not replant in the same place
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
What the Donguibogam records — eumyanggwak (淫羊藿). The Donguibogam lists the plant in its Herb section as eumyanggwak (淫羊藿), also called seonryeongbi (仙靈脾), noting that people commonly call it samjigu-yeopcho. It records a warm nature, with a note that some call it neutral, a pungent taste, with a note that some call it sweet, and no toxicity. It sets down the form — growing in hills and fields, leaves like apricot leaves with seed borne above them, a stem like a millet stalk. The leaves are picked in the fifth lunar month and dried in the sun, and those grown where the sound of water cannot be heard are graded highest. This is a historical medical record and differs from modern medical judgment.
Where the name came from. The old text sets down the history of the name as well: it says the name eumyanggwak arose from the habit of sheep browsing this plant. It is a name explanation handed down in an old text and differs from how the plant is judged today.
Analyses of icariin. The flavone glycoside icariin was isolated from the leaves and is taken as the marker compound in herbal material standards. These are compositional analyses and have nothing to do with preventing or treating disease.
Nutrition
- Icariin (isolated from the leaves) — the flavone glycoside used as the marker compound for this material
- Flavonoid glycosides (present in leaves and stems) — the group of glycosides reported alongside icariin
- Tannins (present in the dried leaf) — compounds discussed alongside the astringency of the infusion
Not a namul Korean epimedium is not a green to blanch and dress. The leafy stems are dried for an infusion or steeped in liquor. Everything said here about composition refers to that dried leaf and is not an instruction to brew one at home.
Icariin The flavone glycoside icariin was isolated from the leaves and serves as the marker compound in herbal material standards. This entry stays with the compositional record.
Drying and steeping Dry the leafy stems spread in a breezy shaded spot. Long exposure to sun fades them, and anything stored damp goes mouldy. A long boil brings the astringency forward.
Pairings
○ Dried jujube — The infusion runs astringent, so dried jujube often goes into the pot with it. A little sweetness makes it easier to drink. Jujube
○ Shade drying — Dry the picked stems spread in a breezy shaded spot. Once fully dry, seal them in a container and keep them somewhere cool.
○ A shaded bed under deciduous trees — It settles well under deciduous trees that cast summer shade. Many people plant it for the reddish flush of the new leaves in early spring.
△ Digging it from the wild — Long collection has made this plant scarce where it grows wild. If you find one on a hillside, leave it where it stands. To grow it, buy a nursery-raised division.
△ Brewing and drinking it long-term on your own — Do not decoct the dried leaf and drink it over any length of time on your own. That goes double during pregnancy or breastfeeding, or alongside any prescribed medication. Where it is needed as medicine, discuss it with a practitioner.
△ Drinking a lot of the steeped liquor — Do not regard liquor steeped with this plant as medicine and drink freely. Steeped liquor is still liquor, and the amount is counted as alcohol.
△ Confusion with look-alike plants — Several mountain plants divide their leaves in threes, so leaf shape alone will not separate them. Meadow rue and its relatives grow in the same places with similar foliage. If you are not certain, do not pick.
Varieties
- Korean epimedium (division) — The species native to Korean mountains. The stem divides into three and carries nine leaflets
- Chinese source species (distinction) — Market material sometimes arrives mixed with Chinese species whose leaf shape differs
Source: Donguibogam, Herb Section 淫羊藿 · Korea National Arboretum, Korean Plant Names Index