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