Beyfuss, Robert Layton. Retired Agriculture Agent and American Ginseng Specialist for Cornell University Cooperative Extension, NY and Vice President American Ginseng Pharm LLC.

(Presented at The Future of Ginseng and Forest Botanicals Symposium, July 12-14, 2017, Morgantown, WV)

Abstract

Wild American ginseng is a plant species of International Concern and is listed on CITES Appendix 2. Current conservation efforts are geared towards protecting existing wild populations by establishing regulations that, among other rules, are intended to prohibit harvest before plants have a chance to reproduce. This presentation will address the following questions: 1) Can wild ginseng regenerate new plants from replanted rhizome/neck fragments containing intact apical buds (vegetative reproduction)? If so, 2) Will plants that have regenerated from rhizome fragments become reproductive sooner than plants arising from seeds planted from harvested plants? and 3) What are the possible conservation/regulatory implications for this data?

In 2006, an experiment was performed to see if wild American ginseng plants could regenerate new root tissue and top growth from their severed rhizomes, with some root tissue left attached and a viable apical bud. The experiment was performed both in a greenhouse environment as well as in a forest environment. A significant percentage of the forest rootlets did survive and produced offspring within 5 years, whereas all the greenhouse plants perished.

Introduction

Wild American ginseng is a native North American herbaceous perennial that is highly valued as a herbal medicine, particularly by practitioners of traditional Chinese medicine. Its continued existence in the wild is of international concern, consequently it is listed on CITES Appendix 2.

Current conservation efforts are geared towards protecting existing wild populations by establishing regulations that prohibit harvest of the wild roots before plants have had a chance to reproduce. Harvested roots must display at least 5 abscission scars indicating that the plant has produced top growth for five seasons. However, age of ginseng plants, as determined by counting abscission scars on rhizomes, is not a reliable predictor of reproductive status for wild ginseng.

According to Professor James B. McGraw, WVU (pers. comm), “age in itself is a poor indicator of life stage generally, and reproductive capacity specifically. This has long been known in population biology as a general truth.”

The regulation requiring visually intact rhizomes with 5 scars removes the most vigorous members of a population, with no real assurance that they have reproduced prior to their harvest. Removal of mature plants does not protect locally adapted gene pools. Most states require the replanting of ripe berries from the harvested roots in the immediate vicinity of where the roots were harvested, however there is no way to insure that the harvested roots had any ripe berries present at all, at the time of harvest. Even if the plants had berries and the berries were carefully replanted, the shortest period of time before the offspring become reproductive is at least 6 or 7 growing seasons.

My hypothesis was: Can wild ginseng plants regenerate new growth from fragments of rhizomes that are replanted on site at the time of harvest?

Surprisingly, there has been very little published research on this topic. The only recent citation I am able to offer is “Recovery of Populations of Goldenseal and American Ginseng Following Harvest” (Van Der Voort et al., 2003). From the abstract of Van Der Voort et al. (2003): “Both rhizomes and roots of goldenseal and ginseng are capable of regenerating plants, conferring a degree of short term resiliency following harvest.”

Unfortunately, this observation is muddled by the inclusion of goldenseal into the research and it was a very small study for ginseng. It is well known that goldenseal easily regenerates from root fragments left in the ground, but no published data relating specifically to ginseng regeneration has been found.

Prior to the neck scar regulations, some ginseng harvesters routinely cut off the main body of the taproot and replanted the intact rhizome with a viable apical bud present. This procedure was used to shorten the time interval between root harvests, allowing root tissue to be harvested more than once from the same plant. As recently as 2015 I have been approached by ginseng diggers in NY wanting to sell roots that had their rhizomes removed and replanted with the explanation that “this is how I was taught to do by my Grandfather.”

Methods

In fall of 2006 a total of 240 “presumed wild” ginseng roots were obtained from 3 sources. 106 of the roots were obtained from a local NY dealer who reported them as being dug in the Catskill mountain and Fingerlakes region of NY, 68 were obtained from a Pennsylvania dealer (including 18 rhizomes only with no shoulder root at all attached) and 66 were dug by this researcher, from 2 locations in NY (Adirondack region and South central NY). Each root was photographed, weighed intact, the cut off rhizome was weighed, rhizome length and age was noted (senescence scars counted), and origin of root was noted.

On November 3, 2006, 116 rhizomes with intact apical buds were re-planted in a beech/red maple forest (Siuslaw Model Forest, Greene County NY) in an area with no recorded presence of ginseng. 16 of these roots were “controls” i.e. entire, intact roots, not severed rhizomes.

Results: Recorded Data

The average uncut root weight was 5.78 grams. This translates into approximately 237 roots per pound dry weight. The average replanted neck weight was 1.04 grams (18% of the total root weight). The average root age based on neck scar counts was 10.9 years.

On November 1, 2006, 124 roots were potted up in a commercial potting soil (Metro Mix # 2) in 4.5 inch pots and placed in an unheated greenhouse. This included 14 uncut, intact “control” roots. All the potted roots in the greenhouse perished and were rotted by May 2007 (including all control plants).

Possible explanations why the greenhouse roots rotted are that the greenhouse heat was turned on 3 times during the coldest parts of winter to melt snow from the greenhouse (February 14, March 17, and April 12) and the inside greenhouse temperature rose to 70 degrees. These warm periods allowed pots to thaw. Potted greenhouse plants are not buffered by surrounding masses of forest soil. In addition, “Metro mix” is a sterilized commercial potting “soil less mix” comprised of chemical fertilizer, peat moss, perlite and vermiculite, not a forest soil. Potted plants were not continually monitored, i.e. watered when the pots thawed.

Lesson #1: Greenhouse studies of woodland plants need to be carefully designed, well simulated, and conducted to mimic natural conditions. Data derived from such greenhouse studies needs to be interpreted in proper context. Regulations based solely on greenhouse studies are not necessarily valid for plants growing in the wild.

Of the 100 experimental plants replanted in the forest, a total of 42 plants produced new top growth (42%) by May 15, 2007 (consistent with Van Der Voort study data). Only 9 of the 16 “control” plants emerged by May 15 (56%). Did they reproduce? Although all the emerged plants were 3 and 4 prongs, and some had flower stalks, they were tiny in stature. None produced berries in 2007 (not even the control plants).

2008 Data from the 2006 experiment: All of the 42 plants that had emerged in 2007 reemerged in 2008, as well as two additional experimental plants that did not emerge in 2007, but 2 of the control plants that did emerge in 2007 did not emerge in 2008. No plants produced berries in 2008.

Lesson #2: Not all forests are suitable sites for growing transplanted ginseng. Although the rhizomes replanted in the forested site provided slightly more of a “real world” simulation compared to the greenhouse phase, it still did not truly represent a “real world” situation in which freshly harvested roots are decapitated and immediately replanted in the exact same habitat they were growing in. It is also noteworthy that all the roots used for this experiment were all stored in a refrigerator for at least 6 weeks prior to replanting. In the winter of 2008, the experimental site was destroyed by a logging activity.

Lesson #3: Don’t retire while a multi-year experiment is ongoing!

Discussion

Anecdotal data garnered by personal conversations with ginseng diggers over the past 30+ years has revealed that the practice of harvesting only a portion of a wild ginseng root, while replanting the rhizome, particularly if any adventitious roots were present, was practiced quite commonly prior to 1999. In situations where the roots were harvested for personal consumption, it was a preferred method to ensure that the patch could be revisited years later with a good chance of repeated harvest. Many small wild ginseng populations have no evidence of successful natural recruitment via seed, although mature 3 and 4 prong plants may be present. This may be partially due to the fact that seedling ginseng plants are far more susceptible to pests such as non-native snails and slugs that are capable of eating newly emerged seedling plants in a matter of a few days, or even less, whereas larger, 3 prong or larger plants are far more tolerant of this type of predation. The majority of “natural” ginseng mortality occurs during its first three years as the root struggles to become established. Once established in a suitable habitat, ginseng plants are capable of living 50 years or longer.

Markets for wild ginseng have changed, and the presence of intact rhizomes indicating roots that are at least 25 years old based on the neck scars have come to command a premium price in recent years. These roots are the most highly regarded by affluent Asian consumers since they are considered as being the most potent. In NY State these so called “long necked” roots, with at least 25 scars, have sold for upwards of $1,000 a pound, fresh weight as recently as 2014, whereas “average” roots with 10 or fewer neck scars sold for 1/3 of that price. The presence of 10 or fewer neck scars has no significant effect on prices whatsoever. In retail Chinese markets in NY City, wild roots with less than 25 scars often have the necks removed prior to sale since they confer no added value.

The five scar neck rule was implemented in 1999, effectively eliminating the practice of replanting rhizomes, as the export of roots without the prerequisite neck scars became illegal.

While the intention of the regulation was to prohibit root harvest before maturity and was partially based on the recorded increases in numbers of roots per dry pound, indicating that smaller and presumably younger roots were being harvested, the practice does target the most vigorous plants within a population. Removal of the “breeders” while allowing juvenile seedlings and two prong plants to survive, if any are even present, can seriously damage the genetic integrity of a small population.

If the goal of the overall ginseng conservation effort is to preserve locally adapted wild genotypes, the mandatory destruction of the established members of a population during harvest needs to be reevaluated. If wild ginseng roots can be partially harvested and then successfully replanted, with a much shorter wait for re-harvest or reliance on seed reproduction, the goal of genetic preservation will be enhanced.

Reference

Van der Voort, M.E., B. Bailey, D.E. Samuel, and J.B. McGraw. 2003. Recovery of populations of goldenseal (Hydrastis canadesnsis L.) and American ginseng (Panax quinquefolius L.) following harvest. American Midland Naturalist. 149: 282-292.