¹Departments of Horticulture, Plant Pathology, and Soil Science, College of Agricultural and Life Sciences and Cooperative Extension Service, University of Wisconsin-Madison, WI 53706.
²Department of Agronomy and Plant Genetics, Minnesota Extension Service, University of Minnesota, St. Paul, MN 55108.
³Former Marathon County Agricultural Agent, Cooperative Extension Service, Courthouse, Wausau, WI 54401-5501.

I. History:

American ginseng (Panax quinquefolius, L.) is a perennial herb native to the deciduous forests of the eastern United States. Wild ginseng once thrived along most of the nation's eastern seaboard, from Maine to Alabama and west to Michigan, Wisconsin and Minnesota. It still grows wild, but it was over-harvested in the mid-1970s and was subsequently defined as an endangered species. Currently, 18 states issue licenses to export it. In Wisconsin and several other states where ginseng is cultivated, a permit is not required to export artificially propagated ginseng.

Ginseng was one of the earliest marketable herbs to be harvested in this country. Wild ginseng was one of Minnesota's first major exports. In 1860, more than 120 tons of dried ginseng roots were shipped from the state to China. American ginseng is similar to Asian ginseng, Panax ginseng, L., which grows wild in Northern Manchuria and has been harvested there for thousands of years.

Ginseng is prized in the Orient for its purported curative properties. Based on an ancient Chinese legend, early emperors proclaimed it a panacea to be ingested or used in lotions and soaps. The genus name, Panax, is derived from the Greek "panakeia," which means universal remedy. The term "ginseng" is derived from the Chinese term "jen-shen," which means "in the image of a man." Ginseng roots shaped like the human body are considered highly desirable. In particular, old roots (some may be nearly a century old) are prized because their longevity is claimed to be transferred to the person who consumes them.

Ginseng root is reputed to lower blood sugar and cholesterol levels, protect against stress, enhance strength and promote relaxation. Koreans have fed ginseng to race horses to enhance their performance on the track. Although some European and Asian studies appear to support some of these claims, American researchers remain skeptical. Ginseng is not a drug and should not be taken as such. It is classified by the Food and Drug Administration (FDA) as a "generally recognized safe food" (GRAS).

Ginseng became a domesticated crop in the late 1800s. Attempts to produce the crop in Wisconsin in the late 1870s failed due to disease. In 1904, the four Fromm brothers from the Wisconsin township of Hamburg, near Wausau, transplanted 100 wild ginseng plants from nearby forests onto a plot of their land and carefully duplicated the natural growth conditions. The perseverance of these early ginseng growers and the ideal growth conditions in Marathon County have made it the ginseng capital of the United States, producing approximately 10% of the world's supply of ginseng root. More than 90% of the cultivated ginseng grown in the United States is grown in Wisconsin, and 90 to 95% of Wisconsin-grown ginseng is produced in Marathon County.

It is estimated that Wisconsin grew 3,000 to 5,000 acres of ginseng in 1990, and sales of the root earned almost $70 million for farmers in Marathon County. Most of Wisconsin's ginseng growers cultivate no more than one acre of the crop annually. Most of the nation's ginseng crop is exported to Hong Kong, where it enters duty-free. Much is then redistributed to other locations in the Far East.

Ginseng can be a profitable crop, but it requires an enormous commitment of time, money and labor for successful commercial production. Ginseng beds in Wisconsin are usually cultivated for three years before harvest, unless disease problems mandate earlier harvest.

II. Uses:

In the Far East, ginseng root is used in toothpaste, soft drinks, tea, candy, chewing gum and cigarettes. It also appears on the market as crystals, extract, powder capsules and is sold as the whole root. In the United States, ginseng and ginseng products are marketed in Asian food and health food stores. Most of the ginseng used in the United States, however, is imported from Korea. The amount of Asian ginseng that is imported is about equal to the amount of higher-priced American ginseng that is exported.

Ginseng seed is also marketed. Ginseng plants generally begin to produce harvestable seed in the third year of growth. It takes approximately 200 plants to produce 1 lb of seed, which may produce 5,000 seedlings.

III. Growth Habits:

American ginseng plants are generally started from seeds. Seedlings or roots for transplanting are available commercially, but are used infrequently. Seeds are planted in the fall and germinate in the spring. Although researchers have examined ways to break this juvenility requirement and hasten germination, it is still not understood.

First-year seedlings produce one compound leaf with three leaflets. This leaf, 1 to 2 in. in height and spread, is the only above-ground growth in the first year. Underground, the plant develops a thickened root about 1 in. long and up to 3 in. wide. At the top of the root, a small rhizome or "neck" develops with a regeneration bud at the apex of the rhizome. In autumn, the leaf drops, and a stem supporting new leaves emerges from the regeneration bud the following spring.

The plant develops more leaves, with more leaflets, each year until the fourth or fifth year. A mature plant is 12 to 24 in. tall and has 3 or more leaves, each consisting of 5 ovate leaflets. Leaflets are approximately 5 in. long and oval-shaped with serrated edges. In midsummer, the plant produces inconspicuous greenish-yellow clustered flowers. The mature fruit is a pea-sized crimson berry, generally containing 2 wrinkled seeds.

After three years of growth, the roots begin to attain a marketable size (3 to 8 in. long by 3 to 1 in. thick) and weight (1 oz). In older plants, the root is usually forked. Wild or high-quality cultivated ginseng root has prominent circular ridges. Highest quality mature root breaks with a somewhat soft and waxy fracture. Young or undersized roots dry hard and glassy and are less marketable.

IV. Environment Requirements:

A. Climate:

Ginseng grows best under conditions that simulate its natural habitat. It requires 70% to 90% natural or artificial shade. Ginseng thrives in a climate with 40 to 50 in. of annual precipitation and an average temperature of 50^oF. It requires several weeks of cold temperatures for adequate dormancy.

B. Soil:

Ginseng generally prefers a loamy, deep (12 in.), well-drained soil with a high organic content and a pH near 5.5. Extremely sandy soil tends to produce long, slender roots of inferior quality.

C. Seed Preparation and Germination:

Most ginseng crops are started from seed, rather than roots or seedlings. This is the least expensive way to start a plantation and may help prevent the introduction of soil-borne disease to new plantations. Ginseng requires 3 to 5 years to produce a marketable crop from seed.

As there is an 18 month seed dormancy, freshly harvested seed cannot be used for starting a crop. It must be stratified for 18 to 22 months before planting. Seed stratification involves soaking the seed in a formaldehyde solution and in a fungicide, then burying the seed outdoors in moist sand. Most seed is already stratified when it is purchased and needs only to be treated with a fungicide and sown. Seed should not be allowed to dry out before or after seeding. (For detailed instructions on seed stratification, see "American Ginseng Culture in the Arid Climates of British Columbia" by Oliver, Van Lierop and Buonassisi).

V. Cultural Practices:

A. Seedbed Preparation:

For planting seeds or seedlings, till the soil to a depth of 8 to 10 in., and remove rocks. For root planting, work the beds 12 in. deep. For best results, mix soil 1 to 1 with fiber-free woodland soil.

Make beds 4 ft wide with alleys between them for walkways and for farm equipment. If the bed is on flat ground, mound the center to facilitate good runoff. Slope the walkways so they will drain water from the beds during heavy rains.

Shade can be provided by wooden lath sheds or polypropylene fabric. Artificial shade should be placed about 7 ft above the ground to ensure good air circulation. Do not use burlap or muslin, which can interfere with air circulation. (For more detailed instructions on how to provide artificial shade, see "American Ginseng Culture in the Arid Climates of British Columbia" by Oliver, Van Lierop and Buonassisi).

B. Seeding Date:

Ginseng seed is generally planted in the fall and covered with mulch until spring. It can also be spring-planted, but if seeding is not completed by May 1, the seed may begin to sprout prematurely.

Roots can be transplanted any time after the tops of the plants have begun to die back but before the ground has frozen.

C. Method and Rate of Seeding:

Plant seedlings 1/8 to 2 in. deep and 4 in. apart in the row. Space the rows 6 in. apart across the bed. The recommended seeding rate for a 4 ft wide bed with 2 ft wide paths between beds is 80 to 100 lb/acre. To keep the seed from drying out, the beds should be covered immediately with 2 to 3 in. of straw.

Plant roots at a 30^o to 45^o angle from the vertical, with the crown of the root 3/4 to 1 in. deep. Cover the bed immediately with 1 to 2 in. of straw. A 4 to 5 in. layer of mulch is necessary on fall transplants to prevent heaving in frost. Some of the mulch can be removed in the spring before the first shoots appear.

Set seedlings 8 in. apart in each direction. Closer spacing tends to increase disease in the plantation.

Light mulching (1 to 2 in. thick) to retain moisture during dry weather is advisable.

D. Fertility and Lime Requirements:

Heavy use of manure or commercial fertilizers lessens the resemblance of cultivated ginseng to the wild root and hence may reduce marketability. Over-manuring may also force growth and lower disease resistance. Although little research in ginseng fertility has been conducted, common practice has been to fertilize as for other root crops. Recommended rates are about 15 lb P₂O₅/acre and 60 lb K₂O/acre for soils testing in the optimum range for vegetables (30 to 45 ppm Bray P₁ and 140 to 200 ppm soil test K).

Nitrogen needs range from 20 to 60 lb/acre, depending on soil organic matter level. (However, some growers have been known to use considerably more.) Growers have tended to use lower-salt fertilizers, such as ammonium sulfate, potassium sulfate and potassium-magnesium sulfate. Although secondary and/or micronutrients are often involved in fertilization programs, little research has been conducted to confirm responsiveness.

Some growers fertilize with leaves or old hardwood sawdust or with ground-up rotted hardwood. Others prefer woodland soil or rotted leaves 4 to 6 in. deep, spaded to a depth of about 8 in. with fine raw bonemeal (1 lb/sq. yd.) worked in.

Fertilizers should be applied during the dormant season at least a couple of weeks before plants emerge.

E. Variety Selection:

Although no improved varieties have been developed, American ginseng shows variations in certain characteristics, particularly in the roots. Plants from the northern part of the country, particularly Wisconsin and New York, are considered good breeding stock, because they furnish roots of good size, weight and shape.

F. Weed Control:

Weeds can be controlled mechanically with mulching and hand weeding and chemically with Fusilade 2000. See Table 1 for instructions on herbicide use.

G. Diseases and Their Control:

Ginseng is susceptible to a number of fungal diseases, including Alternaria leaf and stem blight, Phytophthora root rot and foliar blight, seedling damping-off caused by Pythium and Rhizoctonia, rusty root and root knot nematode. Ginseng gardens that are cultivated in the woods may suffer less from diseases than do plantings under artificial shade.

To minimize disease problems, select a growing site with good drainage. Good air circulation is also crucial and can be attained by providing cleared areas (walkways) around the beds, relatively uncrowded spacing and control of weeds. Thin spacing also reduces the likelihood of disease spread through foliar or root contact. Wisconsin growers generally do not reuse a ginseng field for succeeding ginseng crops.

Table 1 shows pesticides labelled for nationwide use on ginseng. The University of Wisconsin has obtained approval from the Environmental Protection Agency (EPA) (Sec. 18 and Sec. 24) for several additional fungicides. Approval is granted for use in Wisconsin only, and use must be reported to the Wisconsin Department of Agriculture. Consult your local County Extension Agent each year to find out which pesticides may be applied to ginseng in your area.

H. Insects and Other Predators and Their Control:

Ginseng is sometimes attacked by white grubs and wireworms. Voles and field mice may feed on the roots. See Table 1 for recommended pesticides.

Table 1. Pesticides labeled for nationwide use on cultivated ginseng as of November 1, 1991. Use only approved materials…Follow label directions!
Pest	Materials	Treatment(s)	Restrictions/Comments
ALTERNARIA Leaf and Stem Blight	TankMix ROVRAL 50W or ROVRAL 4F (Rhone-Poulenc)	2 lbs/acre and	Best if applied 8 hours before rain. DO NOT apply ROVRAL within 36 hours of harvest.
ALTERNARIA Leaf and Stem Blight	CHAMPION WETTABLE POWDER hydroxide (Agtrol Chemical)	2.6 lbs/acre in min. 100 ga/acre	Also available as FLOWABLE CHAMP. Tankmix 3.5 pts./acre 2 lb ROVRAL 50W. EPA REG NO: 55146-1
PHYTOPHTHORA Root Rot and/or Foliar Phytophthora	No materials labeled for use on ginseng nationwide
INSECTS (Soil)	DIAZINON 14G (Ciba-Geigy)	14-28 lbs/acre pre-plant and incorporate to 4-8" depth. 21 lbs/acre broadcast over beds (Spring or Summer or Fall)	1 pre-plant & 1 broadcast treatment/year in 1^st and 2^nd seasons only. Recommended broadcast just before rain. DO NOT apply within 1 year of harvest. EPA REG NO: 100-46g
INSECTS (Above ground)	PYREZONE CROP SPRAY (Fairfield American)	Up to 12 oz/acre	A broad spectrum contact spray. EPA REG NO: 4816-490
INSECTS (Above ground)	DIAZINON AG500 (Ciba-Geigy)	0.75 to 1 pt/acre	No more than 1 application/year. DO NOT apply during flowering on 3 and 4 year old plants. EPA REG NO: 100-461
SLUGS	DEADLINE BULLETS (Pace National)	20-40 lbs/acre Apply at 3-4 week intervals as needed.	Follow all label recommendations for storage, application, and disposal of this product. EPA REG NO: 8501-34
WEED CONTROL	FUSILADE 2000 (ICI Americas)	1 qt. Fusilade 2000/acre plus 1% crop oil (e.g., 1 gal/100 gal), or 0.25% surfactant (e.g., 1qt/100 gal)	Apply when grasses are 2-8" tall; before tilling or heading.Direct spray away from ginseng foliage. DO NOT apply within 1 year of harvest. EPA REG NO: 10182-104
All recommendations are in terms of products per acre (not a.i.-active ingredient). Compiled by Jennifer Parke and Brian Hudelson, University of Wisconsin-Madison.

I. Harvesting:

In Wisconsin, most growers harvest ginseng the third year after planting from seed. The roots are dug in the fall and vigorously washed to remove surface soil. It is important to handle the roots carefully to keep the branching forks intact and maintain the natural color and circular markings.

J. Drying and Storage:

Ginseng roots are dried on wire-netting shelves in a heated, well-ventilated room. Since overheating destroys color and texture, begin drying the roots at a temperature between 60^o and 80^oF for the first few days, then gradually increase it to about 90^oF for three to six weeks. Turn the drying roots frequently. Store the roots in a dry, airy, rodent-proof container just above freezing.

VI. Yield Potential and Performance Results:

Yields of dried roots from a well-managed planting average about 1 ton/acre, although greater yields are often reported.

A typical seed yield is 150 to 250 lb/acre.

VII. Economics of Production and Markets:

Ginseng growers typically invest $20,000/acre and 600 hrs of labor annually and get no return on their investment until the third or fourth year. Seed and shading materials alone can cost more than $29,000/acre. It may take 10 years to break even. An average crop might net $30,000/acre, depending on the price, which tends to fluctuate widely from year to year. Prices for dried roots range from $20 to $45/lb. Seed sells for $50 to $100/lb.

In Wisconsin, growers are assessed $0.15/lb of dried root for promotion and research, and the funds are administered by the Ginseng Board of Wisconsin, located in Wausau, Wisconsin. There are several seed and root suppliers and ginseng buyers in Wisconsin. For information, contact the Ginseng Board of Wisconsin, or the Wisconsin Ginseng Growers Association both at 500 3rd St., Suite 208-2, Wausau, Wisconsin 54401 (tele 715-845-7300).

VIII. Information Sources:

* American ginseng: buried in mystery. 1986. Martin, L.J. University of Wisconsin Extension. Rm. 3, Courthouse Annex, Wausau, WI 54401.

* American ginseng culture in the arid climates of British Columbia. 1990. Oliver, A., B. Van Lierop and A. Buonassisi. Province of British Columbia Ministry of Agriculture and Fisheries.

* American Ginseng: Green Gold. 1986. Persons, W.S. Exposition Press of Florida, Inc. Pompano Beach, FL

* The Cultivation of Ginseng. 1985. English, J. The Herb, Spice and Medicinal Plant Digest, Vol. 3(2). Department of Plant and Soil Sciences. Massachusetts Cooperative Extension Service.

* Diseases of cultivated ginseng. 1989. Parke, J.L., and K.M. Shotwell. University of Wisconsin-Madison Agricultural Experiment Station Publication #3465. 16 pp.

* Ginseng: a concise handbook. 1989. J.A. Duke. Reference Publications, Inc., 218 St. Clair River Drive, Box 344, Algonac, MI 48001, 273 pp.

* Ginseng: America's botanical drug connection to the Orient. 1986. Carlson, A.W. Economic Botany 40:233-249.

* Ginseng: Horticulture Facts. Hill, L.L. Cooperative Extension Service. University of Illinois at Urbana-Champaign. VC-29-83.

* Ginseng: industry, botany, and culture. 1987. Proctor, J.T.A., and W.G. Bailey. Horticultural Reviews 9:187-236.

* Growing Ginseng. 1981 (Rev.) Duke, J.A. USDA Farmers' Bulletin 2201.

* Horticulture Updates. 1989. Harrison, H.C. University of Wisconsin-Madison. January-February 1989.

* Postharvest seed maturation of American ginseng: stratification temperatures and delay of stratification. 1988. Jo, J., F.A. Blazich and T.R. Konsler. HortScience 23(6):995-997.

References to pesticide products in this publication are for your convenience and are not an endorsement of one product over other similar products. You are responsible for using pesticides according to the manufacturer's current label directions. Follow directions exactly to protect people and the environment from pesticide exposure. Failure to do so violates the law.