Type: Roots & Stems
Difficulty: Moderate
Season: Fall
Sowing: Root division

Roots & Stems

King Solomon's seal

Polygonatum sibiricum

Polysaccharides and steroidal saponins · a rhizome steamed and dried nine times

Hwangjeong is the rhizome of a perennial in the same group as Korean Solomon's seal. Its leaves look like bamboo leaves, which is why the old Korean name recorded for it means the root of the bamboo-leaved plant. It is a different species from Polygonatum odoratum, the one behind the familiar dungulle tea, though they share a genus, so it is worth reading the name on the packet. The raw rhizome is bitter and harsh, so it is blanched to take that out and then steamed and dried over and over. The Herb section of the Donguibogam enters it as 黃精, its nature level, its taste sweet, with no toxicity, and records 仙人飯 as another name. Shoots rise in the third lunar month to a foot or two, the entry says, with short bamboo-like leaves set in opposite pairs, and the root looks like young ginger and runs yellow. Roots were dug in the second and eighth lunar months and dried in the sun, and for long keeping the text says to blanch them in boiling water to remove the bitterness, then steam nine times and sun-dry nine times. It also draws a distinction: the kind with opposite leaves was 黃精, the kind without was 偏精.

Year-Round Calendar

Sowing

Harvest

Where It Grows

Main producer Wild population Latitudes at 15–22℃ Zoom and pan to explore · temperatures are rough zonal averages

Main producer It grows wild in the mountains of Hebei, Shanxi and Inner Mongolia, and is farmed in quantity in Guizhou, Hunan and elsewhere. Most of the huangjing on the market comes from here.
Wild population It grows wild, though rarely, in the mountains from the central region northward, and is grown in small amounts in the uplands of Gangwon and North Gyeongsang.
Wild population It grows wild in the east, where grassland meets forest.
Wild population It grows wild in the forests of southern Siberia and Primorye.

King Solomon's seal (Polygonatum sibiricum) is native to the northern temperate forests spanning northern China and Mongolia, southern Siberia and Primorye in Russia, and the northern Korean Peninsula. The dunggulle used in the familiar dunggulle tea (P. odoratum) is a different species in the same genus, and in China several species (P. sibiricum, P. kingianum, P. cyrtonema) are handled together under the single name huangjing, so this map should not be read as the distribution of one species.

Optimum: 15~22℃
Range: 5~25℃
Hardiness: Hardy

It grows at the edge of woodland in partial shade, on well-drained ground under a covering of leaf litter. In midsummer, direct sun scorches the leaves, and where water sits the rhizome rots. In winter the top growth dies back, and the plant comes up again from the rhizome, carrying on for many years.

Harvested 3–4 years after planting. Rhizomes are divided and planted in March–April, grown on for three or four years, then lifted in October–November. There is nothing to lift in the year of planting, so the year of planting and the year of harvest are not the same.

In Korea Nationwide

Growers pick a partly shaded spot at the edge of woodland to plant in. Wild stands are scarce in the mountains from the central region northward, and cultivation is in the uplands of Gangwon and North Gyeongsang.

How to grow

Light: Part shade with filtered light. A forest-edge spot that catches only the morning sun suits it; midsummer sun scorches the leaves
Soil and depth: Free-draining soil with leaf mould worked in, at least 30cm deep. Standing water rots the rhizome
Spacing: 25 to 30cm between plants. The rhizome creeps sideways and widens its ground, so allow for it from the start
Watering: Watch it only through the first year. Once settled it largely carries itself on rainfall, and in the rainy season it wants a channel cut to take water away instead
Feeding: Lay leaf mould or well-rotted compost around the crown after leaf fall. Heavy chemical fertiliser softens the rhizome
Harvest: October and November, lifted once the foliage dies back. It takes three or four years from planting for the rhizome to thicken. The Donguibogam records digging in the second and eighth lunar months

What makes the difference. Wash the lifted rhizome, blanch it in boiling water to draw off the bitterness, then steam and dry it repeatedly. The mark to work to is a deepening dark colour with the sweetness forward

Why this one is harder. There is nothing to lift in the year you plant. Three or four years are needed for the rhizome to thicken, so it pays to lift on one side while planting the other and stagger the years. As you lift, cut the front section carrying the buds and bury it again; it carries on from there

Common problems

Root rot You will see Shoots fail to appear in spring, or start and then wilt What to do Avoid spots where water sits and raise the bed. Dig out rotted crowns and do not replant in the same place
Leaf blight You will see Leaves brown off from the tips after the rains and the damage spreads What to do It spreads when wet weather lingers. Take affected leaves off the plot and thin the planting for airflow
Chafer grubs You will see Holes bored into the rhizome, found at lifting What to do Do not dig in half-rotted compost. Pick the grubs out as you lift, and rest badly affected ground for a season

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 — hwangjeong (黃精). The Donguibogam lists it in the Herb section as 黃精 under an old Korean name meaning the root of the bamboo-leaved plant. Its nature is set down as level, its taste as sweet, with no toxicity, and 仙人飯 is recorded as another name. Shoots rise in the third lunar month to a foot or two, with short bamboo-like leaves set in opposite pairs; the stem is soft and resembles a peach branch, yellow at the base and red at the tip. Fine greenish-white flowers open in the fourth lunar month, the seed is white like millet, and some plants set none. The root looks like young ginger and runs yellow, dug in the second and eighth lunar months and dried in the sun. The entry distinguishes the kind with opposite leaves as 黃精 and the kind without as 偏精, and for long keeping it says to blanch in boiling water to remove the bitterness, then steam nine times and sun-dry nine times. What an old medical text wrote differs from how it is judged today.

Compounds of the genus Polygonatum. Repeated analyses report polysaccharides and steroidal saponins isolated from the rhizomes of Polygonatum species. The same work reports that the profile shifts through steaming and drying. This is an analysis of composition.

Names and species. Botanical classification confirms that what is traded as hwangjeong is mainly Polygonatum sibiricum while the dungulle of the familiar tea is Polygonatum odoratum, two species within one genus. This is a record of how the names are used.

Nutrition

Polysaccharides (stored in the rhizome) — storage compounds whose profile shifts through steaming and drying
Steroidal saponins (reported across the genus Polygonatum) — compounds discussed alongside the harshness of the raw rhizome
Mucilage (seeps stickily from a cut surface) — the source of the slippery texture of the rhizome

Raw it is bitter and harsh The raw rhizome is bitter and harsh and is never used as it comes. The standard preparation is to blanch it in boiling water to draw that out, then steam and dry it repeatedly, and the Donguibogam likewise sets down nine steamings and nine dryings in the sun. Through that process it darkens and the sweetness comes forward.

Polysaccharides and saponins Polysaccharides and steroidal saponins are reported in the rhizomes of the genus Polygonatum. Analyses also report that their profile shifts through steaming and drying. This entry stays with the compositional record.

Not the same species as dungulle tea The familiar dungulle tea is Polygonatum odoratum, while what is traded as hwangjeong is Polygonatum sibiricum. Same genus, different species, and prepared differently. Read the name and the botanical name on the packet together.

Brewing it Put the steamed and dried pieces in water and draw them out over low heat. Hard boiling brings a dull, heavy note forward. A large batch sours, so brew only what will be drunk and refrigerate what is left once cool.

Pairings

○ Brewed with jujube and ginger — Add a few jujubes and a little ginger to the steamed, dried rhizome and draw it out over low heat. The jujube brings sweetness, the ginger settles the finish. Do not boil it hard; drop the heat once steam rises and let it steep. Jujube

○ With roasted grain — Brewed with roasted barley or corn, the toasted note leads and it drinks easily. A small amount of hwangjeong gives both colour and sweetness. In summer, brew it, cool it and refrigerate.

○ Young spring shoots as a green — The young shoots that rise in early spring are blanched and dressed. Blanch briefly, rinse cold, squeeze dry and dress with doenjang or perilla oil. Taking every shoot leaves the rhizome no growth for the year, so cut only a few.

△ Confusion with lily of the valley — The real hazard when picking young shoots in early spring is lily of the valley. Its leaves resemble the young shoots of the Solomon's seal group and it carries cardiac glycosides, behind repeated poisonings reported in Korea. Lily of the valley puts up two or three leaves clustered at the base with a separate leafless flower stalk rising between them, while the Solomon's seal group carries its leaves in sequence along a single stem. If you are not certain, do not pick.

△ Do not brew it raw — The raw rhizome is bitter and harsh enough to irritate the throat. What you dig is washed, blanched to remove the bitterness, then steamed and dried. Even dried pieces that look pale and taste of nothing are under-steamed, and want steaming and drying again.

△ Do not set a medicinal dose yourself — Hwangjeong is sold as a drug in the herbal markets. Drinking it as a weak tea and taking it as a decoction differ in both purpose and quantity, so do not decide the amount from an old record. If you are pregnant or taking medication, check with a practitioner or pharmacist first.

Varieties

Polygonatum sibiricum (rhizome) — The species traded as hwangjeong. Leaves whorled, their tips curling like hooks
Polygonatum falcatum (rhizome) — A species native to Korean hills. Records show it handled as hwangjeong alongside the first
Polygonatum odoratum (rhizome) — The species behind the familiar dungulle tea. Same genus, different species from hwangjeong

Source: Donguibogam, Herb Section 黃精