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New Crops News, Spring 1994, vol. 4 no. 1

Commercial Production of Ginseng and Goldenseal

Ginseng

Ginseng is an herb that has been used for centuries in the Orient for medicinal purposes. Since the 18th century, American ginseng (Panax quinquefolium L.) has been dug from the wild and exported to the Orient. Ginseng has provided millions of dollars in income to Kentucky diggers, dating back to large shipments reportedly made by Daniel Boone. Currently, sales of ginseng bring in around $5 million annually to Kentucky diggers of wild ginseng and growers of cultivated ginseng.

Because wild ginseng commands prices well over $200 per lb., much wild ginseng is being dug at a very young age and early in the season before the plants have a chance to produce seed. This has resulted in concern that our wild populations may be exterminated as has occured with wild ginseng in China. The federal government has placed ginseng on the list of plants that may be in danger of extinction; each state must have a program of ginseng certification, monitoring, and research to comply with federal requirements for ginseng export. As a result of relatively high prices being paid for wild ginseng roots, there has been increased interest in growing ginseng as a cultivated crop.

Plant Characteristics

American ginseng (Panax quinquefolium L.) belongs to the Aralia family (Araliaceae). The plant is native to rich, hardwood forests in the eastern United States and Canada. The seed produced in the umbel requires 18-20 months of after-ripening before a plant will appear. The seedlings have three leaflets, somewhat resembling wild strawberry leaves. Older plants fork, and each fork (or "prong") usually holds three to five palmately arranged leaflets. Additional prongs are produced annually or biennially. Mature plants are 1 to 2' tall, and mature stems are about the diameter of a pencil.

The leaves turn yellow and the stems die each fall, leaving a scar where the stem was attached to the root. A new bud for next season's stem is formed on the opposite side of the root in mid-summer. The age of a particular root can be estimated by counting the scars.

Ginseng plants usually begin to lower and set seed in their third growing season. A cluster of greenish-white blossoms forms an umbel on the stalk in June or July. Small green berries about the size of small beans are produced, and in late summer, the berries turn red. Each berry contains one to three flat seeds. Ginseng appears to be self-pollinated.

Cultivated plants become increasingly larger until their fourth, fifth, or sixth year, after which growers usually harvest the roots for market. At this time, roots are up to 4" long, 1" thick, and are often forked.

Selecting a Growing Site

Ginseng has rather specific soil and light requirements. The soil must be moist, well-drained and high in organic matter. Plants are quite susceptible to diseases on poorly-drained soil, and roots do not develop well in heavy clay soils. Sandy soils must be amended with organic matter. A pH of 5.5 to 6.5 is desirable, and soils should have good supplies of calcium and phosphorus.

Ginseng will not tolerate much sun; 70 to 80% shade must be provided. Excess shade will reduce yields of roots and seeds, while too much sun will burn the leaves, reduce yields or even kill plants. Shade can be provided in a wooded area or under a lath or polypropylene shade house. The best wooded sites are those with long-lived, deep-rooted, deciduous trees. Oak hickory, beech, poplar, and walnut trees are good, although oak leaves do not decompose quickly and may smother small plants. Ginseng roots may be stunted or difficult to dig under shallow-rooted trees, and short-lived trees may leave gaps in the canopy as they die. Shallow-rooted or short-lived trees include maples, elms, elders, redbud, dogwood, and ash.

Preparing the Soil

Ginseng seeds or roots can be planted in seedbeds or in permanent beds. Seedbeds should be well-tilled, with no weeds, grasses, or roots remaining. The soil should be worked to a depth of 6" or more.

To prepare permanent beds under artifical shade, plow, disc, and rotovate the soil. Four to six inches of leaves, rotted sawdust, or other organic material may be worked in to a depth of 8". Have your soil tested early in the planning stage so that any needed fertilizer can be added during the disking or rotovating operations. Do not add chemical fertilizer to the soil unless a soil test indicates the need, since high fertility may induce rank growth, lower disease resistance, and lower the resemblance of the cultivated root to a wild root.

In a wooded site, remove all of the understory growth and any large trees that are not necessary for shade. A bulldozer may be necessary to clear large areas. If so, do not use a regular cutting blade but a blade with spikes spaced 1' apart on the bottom. These spikes will remove vines while keeping leaves and topsoil intact. Disc the soil 6 to 8" deep, going over the area repeatedly in different directions. Calcium, phosphorus, and limestone should be added during the initial soil preparation as indicated by soil tests. After rotovating, throw the soil from the walkways into the beds with a bed maker or a spade. Four-foot-wide beds are convenient for most people to work, but some growers make beds as wide as 6'. The beds should be about 6 to 8' high. Raised beds are very essental to allow for good drainage. The crowns of the beds should be slightly rounded. Try to situate trees in the beds, not in the paths.

Building a Shade House

Ginseng may be grown under "artificial" shade in houses made of wood lath or polypropylene shade cloth. Support posts are usually 4x4" treated lumber, or 6" diameter locust or cedar posts cut to 9' so that 2' may be buried and the structure will be 7' high. For a lath house the posts are set on 12' intervals in a north-south direction and on 11' intervals in an east-west direction. The posts running in the N-S direction are connected by 2x6" riders nailed to the top edge of the post. The inside riders are all 12' long; 14' riders are used on the ends to give a 2' overhang. The lath frames are constructed of three lx3" runners 12' long to which 4' lath are stapled. The laths (usually white cedar) are 1 1/2x3/8" and are spaced 5/8" apart; 7" at each end of the frames have no laths.

Support posts for polypropylene houses are spaced 24' on center and are connected by 1/4" cables over or through the posts. Dead men are buried in the ground to anchor the cables. The shade fabric is conneded to the cable with S-hooks which pass through grommets in the fabric. The shade material must be removed each fall to avoid damage from snow.

The approximate amounts of materials required for a 1-acre shade house are:
Polypropylene house

  • posts--100
  • cables--4720'
  • shade cloth--5760 sq yd
    Lath house
  • posts-- 361
  • riders--4360'
  • lath--~1200, 4x12' shades

    Planting Seeds or Roots

    Ginseng beds can be started with stratified seeds or with one or two-year-old roots. (Stratified seeds are seeds that have been kept in moist sand for about a year. If planted in the fall, they will germinate and produce plants the following spring.) Spacing of ginseng roots can vary from 2x6" to 8x8". Stratified seed are purchased for shipment and seeding in the fall. The preferred times for sowing stratified seed are October and November. Seed can be sown in the spring; however, if it's not done early (late February to early March) much of the seed may sprout, necessitating hand planting. For direct seeding the seed are usually sown with a mechanical seeder; garden seeders are commonly used for small plantings. Sieve the seed free of the sand in which it was stratified, then place in a bucket of water to float off dead, empty seed. Spoon the seed out and allow it to surface dry so that it will flow readily in the mechanical seeder. A setting on the mechanical seeder for peas or beets usually works well. Sow the seed 1/2 to 1" deep in rows 6 or 8 inches apart. If you do not use a seeder you may hand drop the seed into furrows and cover by raking. Another method of hand seeding and spacing at the same time is to cut a 5' piece of reinforcement wire with 6" squares, lay it down on the raised bed and dibble 2-3 seed in the center of each square. Seed rows are usually 6" apart, and this method sets both seed row spacing and sparing between the plants in the row.

    Seeds can be started in seedbeds and transplanted to permanent locations later. This method allows a smaller area of ground to be prepared initially and makes weed control easier. Also, when the roots are being transplanted a year or two later, diseased roots can be discarded. There are 7000-8000 seed per lb.

    Most growers report sowing 50 to l00 pounds of seed per acre. The seeding rate will vary with the row spacing, the within-row spacing, the bed width and the path width. Growers who sow 50 to 100 lb. of seed per acre are spacing plants much closer than 4x6" in the rows since all seed will not germinate. However, ginseng usually germinates at about a 70% level. Higher and lower germination percentages frequently occur. Large growers prefer to sow at the higher rates to avoid skips or bare spots in their beds.

    Plantings may be started by purchasing 1-year-old roots. This is more expensive than starting from seeds. There are two major advantages to starting with roots for the novice who wants firsthand experience at growing ginseng before attempting a larger commercial planting. First, the roots can be spaced so as to make maximum use of the area planted. Second, the plants will come into flowering and seeding one year sooner, providing the grower with seed for further expansion.

    Mulching

    Ginseng should be mulched to simulate the cool, moist conditions of the forest floor, to smother weeds and to prevent frost heaving in the winter. Mulching should be done immediately after fall seeding, using 1 to 2" of organic material.

    Prior to the growing season, there shout be 2 to 3" of mulch on the beds. Leaf litter, sawdust or straw can be used. You will need about 3,000 cubic feet of sawdust or at least 2 tons of straw to mulch an acre. Mulch may encourage rodents that feed on seeds and roots. Rodent poison should be used during the entire year.

    Harvesting Seeds

    Seed from plants 3 years old and older are harvested beginning in August as the berries turn red. Several pickings are needed for maximum seed harvest. The seed has an immature embryo and will not germinate until it receives cycles of cool and warm temperatures, usually requiring 18 months to complete. In order to provide the proper conditions to mature the embryo, seed should be de-pulped and placed in moist sand.

    De-pulping can be accomplished by placing the berries in cloth bags and mashing them daily for about 5 days to burst the berries and free the seeds. The pulp and empty seeds can be floated off and the seeds washed. Clean seeds should be placed in moist sand in a box with a screen top and bottom and held under natural conditions outdoors by burying the box in a well-drained area. The top of the box should be at least 4" below the soil. An alternate method is to place the box of seed in a protected building or basement area where temperatures will be below 45°F during the winter but will not go below 25°F for extended periods. Check the seed regularly to be sure that the sand is moist. The seed need a short, warm-moist period (1 to 2 months) followed by a cool-moist period (3 to 5 months) followed by another warm-moist period (4 to 6 months) and finally another cool-moist period (3 to 5 months).

    Growers have reported seed yields of 150 to 250 lb. per acre. With a market value of around $100 per lb., seed should bring about $10,000 to $25,000 per acre per year once the plants come of seed bearing age.

    Harvesting and Drying Roots

    The roots can be harvested once they reach a fresh weight of about 1 ounce, usually within 4 or 5 years. They are harvested in the fall after the leaves die.

    Damaged roots are much less valuable than whole roots; harvest the roots carefully to avoid breakage. Harvesting can be done by hand, with a garden fork or with a mechanical digger which is a modified potato digger. Roots are placed in a tub or on a screen and washed before the soil attached to them dries.

    Roots can be dried in the open or in drying rooms with forced hot air. If dried outdoors, place the roots on screens in the shade. Turn them daily and inspect for mold. If mold is present they can be moved into the sun but only for short periods; avoid overheating.

    Once the roots are dry, store them in a dry, rodent-proof area until they are ready to be sold. Many growers store and ship ginseng in large cardboard drums that hold 50 to 100 lb. of roots each. One acre should yield at least 1500 to 2000 lb. of dry roots.

    Pests and Diseases

    Insects, diseases, rodents, weeds, and thieves may all plague ginseng gardens. Pesticides are rarely labeled for use on minor crops such as ginseng due to the substantial commitment of time and money necessary to obtain registration. However, work is underway to obtain the information necessary for pesticide use on the crop.

    Insect pests of ginseng are basically those that feed on a variety of plants that grow in "ginseng-type" habitats. Insects are not a major problem.

    Ginseng diseases occur on both foliage and roots. Diseases of leaves and stems are usually caused by fungi and include Alternaria blight, gray mold (Botrytis), and anthracnose. Root rot diseases are caused by Alternaria, Phytophthora, Ramularia, Rhizoctonia, Fusarium, and Verticillium fungi. Root knot nematodes may also be a problem. Many diseases can be controlled using fungicides; however, few compounds are cleared and labeled for use.

    Rodents, such as voles or field mice, can do a great deal of damage to established ginseng beds, especially in wooded areas where trees are used as shade. These creatures make holes into the beds or get into tunnels made by moles and then feed on the ginseng roots. Grain treated with zinc phosphide or Warfarin, is used by some growers to help solve this problem.

    Weeds can also be a serious problem. Only a limited amount of research has been done with the use of herbicides on ginseng beds. Hand pulling of weeds combined with the use of a mulch is the only recommendation at present.

    Theft is one of the major concerns of Kentucky ginseng growers.

    Goldenseal

    The juice of the fresh roots of Goldenseal (Hydrastis canadensis L.) has been used as a dye. The dried roots are extremely bitter tasting. The desirable compounds in the root are the alkaloids hydrastine and berberine. The dried roots are used for many medicinal purposes, especially for eye, skin, and digestive disorders. It is commonly available in health food stores as a tea, powder, or in capsule form.

    Goldenseal is a naive perennial and occurs over the same range and under the same wooded conditions as ginseng. The cultural requirements for Goldenseal are the same as for ginseng and it is often grown under the same wooded conditions or shade structure. Goldenseal is an excellent crop to follow ginseng since a second crop of ginseng usually cannot be grown economically on the same land.

    Goldenseal plants emerge in early spring from buds on perennial rootstocks. The plant grows 10-15" tall and each bud producing usually two leaves. The leaves are five lobed and measure up to 8" long and 12" wide. Flowering occurs in late April or May, and red fruits develop in July or August. The fruit resembles a large red raspberry and contains 10 to 25 seed. The plant dies slowly after the fruits ripen. The root is a horizontal rhizome 1/2&-3/4" thick with many fibrous roots.

    Goldenseal is propagated by seed, rhizome divisions, or rootlet cuttings. Seed require stratification (moist-chilling) before they will germinate. Collected fruits should be mashed lightly and fermented in water for several days to facilitate separating the pulp from the seed. The seed should never be allowed to dry; they may be placed in moist sand and kept in a shaded area until fall when they may be sown outdoors in a prepared bed. Cover about 1/2" deep and apply 2" of mulch. Most of the mulch should be removed in spring before the seedlings emerge. The seedlings will not effectively come up through the mulch and will be choked out if the mulch is not removed. The seedlings do not look like the mature plant initially; two rounded cotyledonary leaves appear first. Transplant the rootstocks to permanent beds when the tops die down. Set the rootstocks on a 6-6" or 8-8" spacing.

    For vegetative propagation, the rhizomes may be dug in the fall, divided into 1/2" or larger pieces preferably with a bud on each piece. These should be replanted 1" deep and at an 8x8" or greater spacing. The rootlets with buds may be cut in pieces 1 1/2-2" long and replanted 1" deep in a nurse-bed spaced about 1 inch apart. Many rootlets without buds and treated in this same manner will often produce plants. These can be replanted to permanent beds after one or two growing seasons. The beds should be mulched with 2" of bark, leaf mold, or straw for winter protection.

    The plants require three to five years growth before harvesting. Often after five years the center portion of the root mass will become crowded and begin to die; plants should be harvested before this occurs. Dig the roots in the fall after the tops have died down. Wash and dry gently; artificial heat may be used, but do not cook the roots. Retain as many of the fibrous roots as possible. The dry weight will be about 30% of fresh weight. The leaves and stems also have commercial value but must be harvested while still green (about September) and dried. Harvesting stems and leaves will reduce root growth, so this should be delayed as long as possible.

    L.P. Stoltz
    University of Kentucky