With the demand for ginseng increasing as Asian countries experience a growth in expendable wealth, cultivation of ginseng has become a popular enterprise. Ginseng in cultivation is exposed to dramatically different conditions than those experienced by ginseng in the wild. Naturally, ginseng cultivators have selected ginseng seed stock that perform better under these artificial conditions. These seeds are then purchased by people all over the eastern United States who are interested in farming ginseng, simulating wild ginseng, or restoring natural populations by broadcasting seeds into the forest. Inevitably, cultivated genotypes infiltrate natural populations. This may occur when pollen is carried from cultivated plants to wild ginseng, or simply when the seeds from cultivated plants are sown in woodlands.
On the surface, the introduction of cultivated plants into the wild may not seem like a threat to ginseng. However, there is growing evidence that many populations of ginseng are locally adapted, meaning that the populations have undergone genetically-based phenotypic changes which allow that population to thrive at a particular site. You can imagine that introducing cultivated ginseng, bred for survival in artificial agricultural conditions, may negatively affect the long-term fitness of wild ginseng populations, by breaking-up the suite of traits that constitute local adaptation. The extent of contamination of wild populations by these cultivars is unknown. We do know that crosses between wild and cultivated plants yield morphologically distinct offspring (Mooney and McGraw 2007). Therefore, applying Aldo Leopold's 'precautionary principle', the conservation biologist's recommendation is to keep cultivated genes separate from wild populations. An economic reason for such isolation may be found as well: If the economic premium the market yields for truly wild plants is based on genetic and biochemical differences between cultivated and wild, then it makes good economic sense to keep the two groups isolated since cultivars could dilute the value of wild plants.