Huanglian is a commonly used medicinal herb for clearing heat and drying dampness. It consists of the dried rhizomes of Coptis chinensis Franch., Coptis deltoidea C.Y. Cheng et Hsiao, or Coptis teeta Wall.—all belonging to the genus Coptis in the Ranunculaceae family. These three species are commonly known as “Weilian,” “Yilian,” and “Yunlian,” respectively.Weilian and Yalian are primarily produced in Sichuan and Hubei. Yunlian is primarily produced in Yunnan. It has the effects of clearing heat, drying dampness, purging fire, and detoxifying.When taken internally, it is used to treat damp-heat-induced fullness and distension, vomiting and regurgitation of acid, diarrhea and dysentery, jaundice, high fever with mental confusion, excessive heart fire, restlessness and insomnia, palpitations, blood-heat-induced vomiting and nosebleeds, red eyes, toothache, diabetes, and abscesses, boils, and carbuncles;When applied topically, it can treat eczema, damp sores, and purulent discharge from the ear canal.
Coptis
Huanglian is a commonly used medicinal herb for clearing heat and drying dampness. It consists of the dried rhizomes of Coptis chinensis Franch., Coptis deltoidea C.Y. Cheng et Hsiao, or Coptis teeta Wall.—all belonging to the genus Coptis in the Ranunculaceae family. These three species are commonly known as “Weilian,” “Yilian,” and “Yunlian,” respectively.Weilian and Yalian are primarily produced in Sichuan and Hubei. Yunlian is primarily produced in Yunnan. It has the effects of clearing heat, drying dampness, purging fire, and detoxifying.When taken internally, it is used to treat damp-heat-induced fullness and distension, vomiting and regurgitation of acid, diarrhea and dysentery, jaundice, high fever with mental confusion, excessive heart fire, restlessness and insomnia, palpitations, blood-heat-induced vomiting and nosebleeds, red eyes, toothache, diabetes, and abscesses, boils, and carbuncles;When applied topically, it can treat eczema, damp sores, and purulent discharge from the ear canal.
Chinese Name : 黄连
Latin Name : Coptidis Rhizoma
Aliases : Wanglian, Zhilian
Authentic Producing Area : Weilian and Yilian are primarily produced in Sichuan and Hubei; Yunlian is primarily produced in Yunnan
Nature, Flavor & Meridian Tropism : Bitter in taste, cold in nature; enters the Heart, Spleen, Stomach, Liver, Gallbladder, and Large Intestine meridians
Benefits & Efficacy
Benefits
Clears heat and dries dampness; purges fire and detoxifies.
Indications
For internal use, it is primarily used to treat damp-heat-induced fullness and distension, vomiting and regurgitation of acid, diarrhea and dysentery, jaundice, high fever with mental confusion, excessive heart fire, restlessness and insomnia, palpitations, blood heat-induced vomiting and epistaxis, red eyes, toothache, diabetes, and abscesses, swellings, and carbuncles; for external use, it is primarily used to treat eczema, damp sores, and purulent discharge from the ear canal.
Usage and Dosage
Internal use: Decoct and take 2–5 g. External use: Apply as needed.
Precautions
1. Contraindications for Combining with Chinese and Western Medicines (1) It may reduce the activity of trypsin and pepsin; therefore, concurrent use is not recommended. (2) The injection solution is extremely unstable when combined with penicillin; therefore, concurrent use is not recommended. (3) Berberine is a strongly basic alkaloid that can form precipitates with various acidic drugs; therefore, it should not be combined for injection. (4) Reserpine may inhibit the antihypertensive effect of Coptis; concurrent use is not recommended. (5) Propranolol hydrochloride may significantly inhibit the antihypertensive effect of Coptis; concurrent use is not recommended. (6) Concurrent use with digitalis glycosides is not recommended, as it may lead to elevated blood concentrations of digitalis glycosides and increase the risk of digitalis toxicity. (7)It should not be used in combination with Western alkaloid drugs such as atropine, theophylline, and caffeine, as this may increase drug toxicity and lead to drug poisoning. (8) It should not be combined with iodine-containing preparations, strongly alkaline Western medicines such as sodium bicarbonate, or heavy metal drugs such as ferrous sulfate, magnesium sulfate, and aluminum hydroxide. 2. Dietary Contraindications Avoid pork and cold water.
Chemical Constituents
It primarily contains alkaloids such as berberine, coptisine, methylcoptisine, parmatine, yagenine, africanophylline, epiberberine, berberamine, and magnoline. Among these, berberine has the highest content, accounting for 40%–50% of the total alkaloid content, and the berberine content in “Weilian” is generally higher than that in “Yilian.”
Pharmacological Actions
This product primarily exhibits antimicrobial, antibacterial toxin, anti-inflammatory, antipyretic, antidiarrheal, and hypoglycemic effects.
Relevant Discussions
1. *Shennong’s Classic of Materia Medica*: “Treats heat-induced eye pain, tearing due to corneal injury, improves vision, and addresses intestinal disorders, abdominal pain, and dysentery, as well as swelling and pain in the female genitalia.”
2. *Supplement to the Classic of Famous Physicians*: “Treats cold and heat disorders of the five viscera; chronic diarrhea with pus and blood; alleviates thirst; relieves severe fright; eliminates water retention; strengthens the bones; regulates the stomach and fortifies the intestines; benefits the gallbladder; and treats mouth ulcers.”
3. *The Pearl Sack*: “It has six uses: first, to clear heart fire; second, to remove damp-heat from the middle jiao; third, it is essential for treating all types of sores; fourth, to dispel wind-dampness; fifth, to treat sudden onset of red eyes; and sixth, to stop bleeding in the middle jiao.”
4. *Classification and Characteristics of Medicinal Herbs*: “It purges heart fire, eliminates damp-heat from the spleen and stomach, and treats restlessness, nausea, and pent-up heat in the middle jiao accompanied by a persistent urge to vomit.”
5. *Ben Cao Zheng Yi*: “Coptis is extremely bitter and extremely cold; its bitterness dries dampness, and its coldness overcomes heat. It can drain and descend all excess dampness and fire, treating heat in the heart, spleen, liver, and kidneys, as well as fire in the gallbladder, stomach, and small and large intestines. It clears wind-fire eye disorders in the upper burner, alleviates vomiting caused by liver-stomach disharmony in the middle burner, and relieves abdominal pain and constipation in the lower burner—all through its effects of drying dampness and clearing heat.”
Applications
Clinical Applications
1. To treat epigastric and abdominal fullness and nausea or vomiting caused by damp-heat obstructing the middle jiao and impaired qi circulation, it is often combined with Perilla leaf, such as in the Perilla Leaf and Coptis Decoction (formula from *The Meridians of Warm-Heat Diseases*, name cited in *Gynecology in Traditional Chinese Medicine*), or with Scutellaria, Dried Ginger, and Pinellia, such as in the Pinellia and Coptis Decoction for Draining the Heart (from *Treatise on Cold Damage*); to treat vomiting due to stomach heat, it is combined with gypsum, as in the Shi Lian San (from *Xian Nian Ji*); to treat distension and pain in the flanks and vomiting with acid regurgitation caused by liver fire invading the stomach, it is combined with evodia, as in the Zuo Jin Wan (from *Dan Xi Xin Fa*);to treat spleen-stomach deficiency-cold with vomiting of sour fluid, it is combined with Ginseng, Atractylodes, Dried Ginger, etc., as in Lianli Decoction (*Zheng Yin Mai Zhi*).
2. An essential herb for treating diarrhea and dysentery; effective when used alone.For treating diarrhea and dysentery caused by damp-heat, with abdominal pain, tenesmus, and a sensation of incomplete evacuation, it is combined with Mu Xiang, as in Xiang Lian Wan; for treating damp-heat diarrhea and dysentery complicated by exterior syndrome with fever, it is combined with Ge Gen, Huang Qin, and others, as in Ge Gen Huang Qin Huang Lian Tang (*Shanghan Lun*); for treating chronic damp-heat dysentery with pus and blood, it is combined with Wu Mei, as in Huang Lian Wan (*Wai Tai Mi Yao*).
3. To treat intense heat in the Three Jiao with high fever and restlessness, it is combined with Scutellaria baicalensis, Phellodendron amurense, and Gardenia jasminoides, as in the Coptis Detoxification Decoction (*Wai Tai Mi Yao*); to treat high fever with mental confusion, it is combined with Gypsum, Anemarrhena asphodeloides, Scrophularia ningpoensis, and Paeonia suffruticosa, as in the Clearing Epidemic and Eliminating Toxin Decoction (*Yi Zhen Yi De*);To treat severe heat damaging yin, resulting in restlessness and insomnia, combine with Scutellaria baicalensis, Paeonia lactiflora, and donkey-hide gelatin, as in the Coptis and Donkey-Hide Gelatin Decoction (*Treatise on Cold Damage*); to treat excessive heart fire and insomnia due to disharmony between the heart and kidney, combine with Cinnamomum cassia, as in the Jiaotai Pills (*Han’s Comprehensive Treatise on Medicine*);To treat vomiting of blood and epistaxis caused by intense internal pathogenic fire forcing the blood to flow erratically, it is combined with Rheum palmatum and Scutellaria baicalensis, as in the Decoction for Draining the Heart (Xiexin Tang) (Jinbian Yaolue).
4. To treat abscesses, swellings, and carbuncles, it is combined with Scutellaria baicalensis, Phellodendron amurense, and Gardenia jasminoides, as in the Coptis Detoxifying Decoction (Huanglian Jiedu Tang) (Wai Tai Mi Yao);To treat redness, swelling, and pain in the eyes, as well as red veins and pinguecula, it is combined with Dan Zhu Ye, as in Huanglian Decoction (*Pu Ji Fang*); To treat stomach fire rising upward, causing unbearable toothache, it is combined with Sheng Di Huang, Sheng Ma, and Mu Dan Pi, among others, as in Qing Wei San (*Lan Shi Mi Cang*).
5. To treat xiaoke syndrome characterized by intense stomach fire, rapid digestion, and excessive hunger, it is often combined with Ophiopogon tuber, as in the Xiaoke Pills (from *Pu Ji Fang*), or with Phellodendron bark to enhance its fire-purging effect, as in the Huangbai Pills (from *Sheng Ji Zong Lu*); to treat xiaoke caused by kidney yin deficiency and excessive heart and stomach fire, it is combined with raw Rehmannia root, as in the Huanglian Pills (from *Wai Tai Mi Yao*).
Related Compatibility
1. Coptis combined with Wood Fragrance: Coptis excels at clearing heat, drying dampness, and stopping diarrhea and dysentery; Wood Fragrance excels at regulating the middle burner, dispelling stagnation, promoting qi circulation, and relieving pain. When used together, these two herbs work synergistically to clear heat, dry dampness, promote qi circulation, and resolve stagnation. This combination is suitable for dysentery, abdominal pain, and tenesmus caused by damp-heat stagnation in the gastrointestinal tract.
2. Coptis combined with Pinellia: Coptis is bitter and cold, excelling at clearing heat, drying dampness, purging fire, and detoxifying; Pinellia is pungent and warm, excelling at drying dampness, transforming phlegm, descending counterflow, and eliminating fullness.When used together, the combination of cold and hot properties harmonizes yin and yang, while the pungent-opening and bitter-descending actions regulate the flow of qi. By eliminating damp-heat and transforming phlegm-turbidity, this combination achieves the effects of purging heat and harmonizing the stomach, descending rebellious qi and resolving fullness, and opening the chest to clear phlegm. It is indicated for chest and epigastric distension, epigastric fullness, vomiting, and hiccups caused by the mutual entanglement of phlegm-heat and impaired qi circulation.
3. Coptis combined with Rhubarb: Coptis clears heat, dries dampness, purges fire, and detoxifies; Rhubarb purges fire, promotes bowel movements, cools the blood, and detoxifies. When used together, the power to purge fire, cool the blood, and detoxify is enhanced. This combination can both clear real heat in the Qi division and purge fire toxins in the Blood division, while also cleansing the intestines and promoting bowel movements.This combination is indicated for epigastric fullness and distension caused by internal accumulation of pathogenic heat; abdominal pain and diarrhea resulting from gastrointestinal damp-heat and stagnation of fire toxins; and redness, swelling, and pain in the eyes, mouth sores, and swollen, painful gums caused by ascending real heat and fire toxins; or for hemoptysis and epistaxis resulting from excessive internal heat forcing the blood to flow uncontrollably.
4. Coptis combined with Water Buffalo Horn: Coptis clears heat, dries dampness, purges fire, and detoxifies, focusing primarily on the Qi level; Water Buffalo Horn clears heat, detoxifies, cools the blood, and eliminates rashes, focusing primarily on the Blood level. When these two herbs are combined, their effects in clearing heat, purging fire, cooling the blood, and detoxifying are enhanced. This combination is indicated for high fever and mental confusion caused by heat invading the营血 (Ying-Blood) in warm-heat diseases, as well as rashes, vomiting blood, and nosebleeds.
Medicinal Identification
Raw Coptis, Wine-Processed Coptis, Ginger-Processed Coptis, and Cornus-Processed Coptis: All four can clear heat, drain dampness, purge fire, and eliminate toxins. They are primarily used to treat gastrointestinal damp-heat, diarrhea, dysentery, and vomiting; intense heat and raging fire; high fever and restlessness; boils, abscesses, and carbuncles; mouth and tongue sores; skin ulcers; and swelling and pain in the ears and eyes.However, raw Coptis (Huanglian) has a stronger bitter and cold nature and excels at purging fire, detoxifying, clearing heat, and drying dampness. It is suitable for treating diarrhea, dysentery, and vomiting caused by gastrointestinal damp-heat; conditions of intense heat and raging fire; high fever and restlessness; mental confusion and delirium; hemoptysis and epistaxis; swollen and toxic boils and carbuncles; mouth and tongue sores; and purulent discharge from the ear canal.Wine-processed Coptis directs the herb’s action upward and moderates its cold nature; it is particularly effective at clearing fire from the head and eyes and is often used for red, swollen, and painful eyes, as well as mouth and tongue sores. Ginger-processed Coptis moderates its bitter and cold nature and enhances its antiemetic effect; it is primarily used to treat vomiting caused by stomach heat and can also be used for nausea and vomiting resulting from damp-heat obstructing the middle burner and disrupting the stomach’s harmonious descent.Corydalis-processed Coptis suppresses its bitter and cold nature, ensuring that Coptis remains cold without causing stagnation. It primarily clears damp-heat from the Qi level and disperses stagnant fire in the liver and gallbladder. It is used to treat damp-heat stagnation in the liver and gallbladder, manifesting as epigastric discomfort and acid regurgitation; it also treats internal obstruction due to food stagnation, which generates dampness and heat, leading to epigastric fullness, diarrhea, or dysentery.
Related Medicines
Coptis Capsules, Enhanced Xianglian Pills, Daoqi Pills, Wan’s Calamus and Calamus-Clearing-the-Heart Pills, and Wuji Pills.
Related Prescriptions
Xiexin Decoction (*Jin Gui Yao Lue*), Zuojin Pills (*Danxi Xinfa*), Kudzu Root, Scutellaria, and Coptis Decoction (*Shanghan Lun*), Coptis Detoxifying Decoction (*Wai Tai Mi Yao*), and Qingwei Powder (*Pi Wei Lun*).
Medicinal Diet Therapy
1. Coptis and White Headwort Porridge
(1) Effects: Clears heat, detoxifies, and cools the blood. Specifically treats conditions such as toxic dysentery.
(2) Ingredients: 10 g Sichuan Coptis, 5 g White Headwort, 30 g japonica rice.
(3) Preparation: Wash the Coptis and Anemone, place them in an earthenware pot, and decoct in water. Strain out the residue and reserve the liquid. In a separate pot, add 400 milliliters of water and boil until the rice blooms. Add the herbal decoction and simmer into a porridge; serve when ready.
(4) Dosage: Take three times daily while still warm.
2. Coptis, Donkey-Hide Gelatin, and Chicken Egg Yolk Decoction
(1) Efficacy: Clears heat and nourishes yin. Indicated for cases where pathogenic heat invades the营 (ying) level, damaging and depleting营 (ying) yin and heart fluids. Symptoms include persistent fever, restlessness preventing sleep, a dark red and dry tongue, and a fine, rapid pulse.
(2) Ingredients: One chicken egg yolk, 12 g Coptis, 3 g Scutellaria, 9 g donkey-hide gelatin, and 3 g white peony root.
(3) Preparation: Rinse the Coptis, Scutellaria, donkey-hide gelatin, and white peony root separately. Place all ingredients except the donkey-hide gelatin into a pot. First, boil the Coptis, Scutellaria, and white peony root with 8 cups of water until reduced to 3 cups. Strain out the residue, then add the donkey-hide gelatin and melt it completely. Next, add the egg yolks, stir until well blended, and cook until done before serving.
(4) Usage: Take in 3 divided doses daily.
3. Coptis and Licorice Decoction
(1) Effects: Clears heat, dries dampness, detoxifies, and kills parasites. Treats whooping cough, conjunctivitis, mouth sores, feverish diarrhea with abdominal pain, pulmonary tuberculosis, sore throat, and cough.
(2) Ingredients: 5 g Coptis, 5 g licorice, and an appropriate amount of white sugar.
(3) Preparation: Wash the Coptis and licorice thoroughly. Place the washed herbs in a steaming bowl, add an appropriate amount of water, and steam over low heat for about 5 minutes. Strain the liquid into a cup, add an appropriate amount of sugar water, stir until well mixed, and let cool slightly before drinking.
(4) Usage: Take three times daily while still warm.
Notes
Patients requiring treatment with Chinese herbal medicine should first consult a licensed Traditional Chinese Medicine (TCM) hospital, where a TCM practitioner will conduct a professional pattern differentiation and prescribe an herbal formula.
Processing & Preparation
Harvesting & Processing
Harvest in the fall; remove fibrous roots and soil, dry, and knock off any remaining fibrous roots.
Processing Methods
1. Coptis: Take the raw herb, remove impurities, rinse thoroughly with water until thoroughly moistened, slice thinly, and air-dry. The raw form is commonly used to clear heart fire and resolve heat toxins.
2. Wine-Processed Coptis: Take Coptis slices, mix thoroughly with yellow wine, let stand until thoroughly moistened, place in a pot, heat over low heat, stir-fry until dry, then remove and let cool. Wine-Processed Coptis is commonly used to clear fire from the upper burner affecting the head and eyes.
3. Ginger-Processed Coptis: Take Coptis slices, mix thoroughly with ginger juice, let them soak until thoroughly moistened, place them in a pan, heat over low heat, stir-fry until dry, then remove and let cool. Ginger-Processed Coptis clears fire in the middle jiao and is particularly effective for treating vomiting caused by stomach heat.
4. Eucommia-Coptis: Take Eucommia bark, add an appropriate amount of water, and decoct for 30 minutes. Strain out the residue and mix the decoction with Coptis slices. Let them sit until thoroughly moistened; once the decoction has been fully absorbed, place them in a pan, heat over low heat, stir-fry until dry, then remove and let cool. Eucommia-Coptis clears damp-heat from the Qi level and disperses stagnant fire in the liver and gallbladder.
5. Stir-Fried Coptis: Place Coptis slices in a pan and heat over low heat, stir-frying until they turn a deep yellow color. Remove and let cool. Stir-fried Coptis has a milder cold nature and is less likely to damage spleen yang.
Storage Methods
Store in a well-ventilated, dry place; wine-processed Coptis, ginger-processed Coptis, and Schisandra-processed Coptis should be stored in airtight containers.
Crude Drug Identification
Properties of Crude Drugs
1. Coptis Rhizome: Often clustered together and frequently curved, resembling a chicken’s claw. Individual rhizomes are 3–6 cm long and 0.3–0.8 cm in diameter. The surface is grayish-yellow or yellowish-brown, rough, with irregular nodular protrusions, and features fibrous roots and their remnants. Some internodes have a smooth surface resembling a stem, commonly known as “guoqiao.”The upper part often retains brown scale-like leaves, and the apex frequently has remnants of the stem or petiole. It is hard in texture, with an irregular fracture surface; the cortex is orange-red or dark brown, the xylem is bright yellow or orange-yellow and arranged in a radial pattern, and the pith is sometimes hollow. It has a faint odor and an extremely bitter taste.
2. Triangular-leaved Coptis: Typically a single branch, slightly cylindrical, slightly curved, 4–8 cm long, 0.5–1 cm in diameter, with a relatively long “bridge.” The apex has a small amount of residual stem.
3. Yunlian: Curved into a hook shape, typically a single branch, relatively slender and small.
Properties of Processed Slices
1. Coptis: Irregular thin slices; the surface is brownish-yellow or yellow; the woody part is golden yellow with a radiating grain; the periphery is dark yellow, rough, and has minute fibrous roots. It is hard in texture, with a faint odor and an extremely bitter taste.
2. Wine-processed Coptis: Resembles Coptis in shape but has a deeper color and a faint aroma of wine.
3. Ginger-processed Coptis: Resembles Coptis, is brownish-yellow in color, and has a slight pungent aroma of ginger.
4. Evodia-processed Coptis: Resembles Coptis, has a deeper color, and possesses the pungent aroma of Evodia.
5. Roasted Coptis: Resembles Coptis and is brownish-yellow in color.
Botanical Information
Botanical Classification
Coptis chinensis, Coptis trifoliata, or Coptis yunlienensis, plants of the genus Coptis in the Ranunculaceae family.
Morphological Characteristics
1. Coptis: A perennial herb. The rhizome is yellow, branched, and densely covered with fibrous roots. Leaves are basal; petiolate; leaf blades are stiffly papery, ovate-triangular, and three-lobed; the central lobe has a slender petiole, is ovate-rhombic, acuminate at the apex, deeply pinnately lobed, and has sharp serrations along the margin; the lateral lobes are unequally and deeply lobed, with the upper surface bearing short soft hairs along the veins.Inflorescences consist of 1–2 stems, forming dichotomous or multibranched cymes with 3–8 flowers; bracts are usually 3, lanceolate; sepals are 5, yellowish-green, narrowly ovate; petals are linear or linear-lanceolate; stamens are numerous; carpels are 8–12, free, with short stalks. The fruit is a capsule.Seeds 7–8, oblong, brown. Flowering period: February–April; fruiting period: March–June.
2. Triangular-leaved Coptis: The rhizome is yellow, unbranched or sparsely branched, with distinct internodes; it is densely covered with numerous fine roots, and the creeping stems grow horizontally. The leaves are ovate and three-lobed; the central lobe is triangular-ovate and deeply pinnately lobed, with the deep lobes more or less closely apposed to one another. The petals are nearly lanceolate, and the stamens are short, measuring only about half the length of the petals.
3. Yunlian: The rhizome is yellow, with closely spaced internodes, few branches, and numerous fibrous roots. The leaves are ovate-triangular, three-lobed; the central lobe is ovate, with an apex that is long acuminate to acuminate, deeply pinnately lobed, and the deep lobes are widely spaced, with a maximum distance of up to 1.5 cm between them. The petals are spatulate to ovate-spatulate, with a blunt apex.
Distribution Area
1. Coptis chinensis: Distributed in Hubei, Hunan, Sichuan, Guizhou, Shaanxi, and other regions; cultivated on a relatively large scale in western Hubei, eastern Sichuan, and southern Shaanxi. 2. Triangular-leaved Coptis: Cultivated at elevations in the Emei and Hongya areas of Sichuan.
Growth Habits
Coptis prefers high-altitude, cool, shaded, and humid environments. It is relatively cold-tolerant but cannot tolerate heat or drought. The optimal growth temperature is 17–22°C. It overwinters under a blanket of snow and ice, with its leaves remaining evergreen and not withering. It is highly responsive to fertilization;the soil should be loose on top and compact below—the upper layer should consist of fertile, loose sandy loam rich in humus, while the lower layer should be clay loam with strong water and nutrient retention capacity and a pH of 5.5–6.5; Coptis is a shade-loving plant with a large leaf area that can utilize sunlight filtering through forest gaps but is intolerant of direct, intense sunlight.
Propagation Methods
Propagated by seed.
Cultivation Techniques
1. After the seeds ripen and are harvested in early May, select a cool, relatively flat hillside and construct a shade structure using branches so that rainwater can naturally flow into the structure. Dig a pit 20 cm deep and store the seeds in layers with moist sand inside the pit. Between October and November, once the seeds have cracked open, broadcast them onto raised beds and cover them with cow or horse manure.In late February of the following year, erect a low shade structure over the ridges. Seedlings emerge in early March; remove fallen leaves from the ridges and thoroughly weed the area. During the seedling stage (May–June), apply a quick-acting nitrogen fertilizer. From October to November, spread finely chopped cow or horse manure, wood ash, and humus-rich soil to help the plants overwinter.In winter, cut down trees to erect a 1.2-meter-high shade structure providing approximately 70% shade. Within the structure, create raised beds 1.6 meters wide. Transplant the seedlings in March of the third year after sowing, when they have developed 4–6 true leaves, spacing them 10 cm × 10 cm apart with a planting depth of 3–5 cm. In recent years, techniques such as intercropping with corn and planting in forest gaps have been adopted.
2. Field Management: Remove weeds promptly after seedlings emerge. Immediately after planting, broadcast a small amount of cow or horse manure and fumigated soil as a “seedling-stage fertilizer.” Apply top dressing once each year in early spring, after the summer seed harvest, and between October and November. In spring and summer, focus on fast-acting fertilizers such as nitrogen and phosphorus; for winter fertilization, use cow or horse manure and fumigated soil as the main sources. Hilling should be performed after applying winter fertilizer.In the first and second years, hill up the soil by approximately 1 cm; in the third and fourth years, by 2–3 cm. Weed before applying top dressing. In the first one or two years after transplanting, the seedlings are small and the open ground is prone to weeds, so weeds should be pulled 4–5 times per year. By the fourth or fifth year, the Coptis plants will have closed the ridges; combine weeding with top dressing three times a year.For Coptis grown under shelters, remove the covering in May of the same year after seed harvest to expose the plants to sunlight, thereby inhibiting leaf growth and promoting the development of robust rhizomes. For Coptis grown in forest stands, begin pruning branches in winter starting in the third year after planting to reduce shading from approximately 70% at planting to 20–30%.
Pest and Disease Control
1. The main disease is powdery mildew; reduce shading to increase sunlight exposure, and control the disease with lime-sulfur solution.
2. Pests include wireworms and mole crickets, which can be controlled through trapping. In early spring, muntjacs and pheasants may damage flower spikes and seeds; erect fences around the planting area and intensify manual trapping to minimize damage.