Though domestic Japanese production of ginseng was expanded under Shogun Tokugawa Yoshimune in the early-to-mid 18th century, it was generally available almost exclusively from Korea. Tsushima han, which managed the Korean trade, thus held a near monopoly on ginseng, which it sold to daimyô, other high-ranking samurai, and select merchant houses out of its domain mansion in Edo. Because there were no limits on how much one could purchase at once, certain buyers acted as speculators, buying up excessive amounts, thus creating shortages and driving up prices, so they could then turn around and sell the ginseng at considerable profit. Because ginseng was such a highly-demanded Korean product, at times it constituted as much as 27% of the volume of Korean goods entering Japan.
The demand for the root was so high that fights and other incidents regularly erupted between people lining up at the Tsushima han mansion to buy some of the limited supply of ginseng, prompting the shogunate in 1690 to order the domain to begin only selling the root through pre-orders. The lords of Tsushima were able also to take advantage of the perceived necessity of a regular influx of ginseng, leveraging it for concessions or the like from the shogunate. In 1700, the shogunate's debasement of silver currency combined with decreased ginseng production in Korea to effectively double the cost of importing ginseng. Tsushima's complaints resulted in the domain being granted a loan of 15,000 ryô to purchase additional ginseng, as well as an increase in the amount of imports they were allowed to sell in Edo, from 1,080 kan (value as measured in silver) to 1,800 kan. Finally, after the shogunate further debased the coinage in 1706, producing ingots that were now only 50% silver, Tsushima requested permission to specially mint 80% pure ingots specifically for use in trade with Korea; permission for this was granted in 1711, considerably alleviating Tsushima's financial & trade difficulties.
Shogun Tokugawa Yoshimune, seeking to stem the tide of silver flowing out of the country, initiated a series of programs to encourage domestic production of ginseng, among other products. It soon came to be produced in many regions throughout the archipelago, the area around Nikkô being just one prominent site of production. In 1718, Yoshimune had Tsushima officials gather information about Chinese and Korean plants, animal materials, and other medicinal products. Samples of Korean ginseng obtained via Tsushima were then used to facilitate domestic production. Yoshimune also had officials in Nagasaki interview Chinese and Dutch merchants about such materials, and in 1722 commissioned a comprehensive survey of the flora and fauna already prevalent in Japan, all the way from Ezo to Nagasaki, an undertaking which was not completed until over thirty years later, in 1753.
In the 1740s, Chinese merchants at Nagasaki began to introduce "Canton ginseng" into the market. Though popular among customers, many Japanese physicians and botanists were skeptical, questioning why Japanese should rely upon it to have medicinal qualities when the Chinese didn't grow it nor use it themselves. Rather, this was a foreign variety grown and harvested by Native Americans, who did not use it for anything but only sold it to Europeans, who then in turn sold it at Canton. By 1763, these Japanese scholars convinced the shogunate to ban the import of this inferior variety. In that year, kanjô bugyô (Magistrate of Finance) Isshiki Masahiro (d. 1770) established a ninjinza, or Ginseng Guild, which would have a monopoly on the market for ginseng. Based at an office in the Kanda neighborhood of Edo, and headed by botanist and physician Tamura Gen'yû, the guild was comprised of 28 licensed retailers spread across the realm, and worked to control both the distribution of imported and domestic ginseng, as well as prices and quality. The ban on inferior Chinese ginseng only lasted until 1788, however, as Matsudaira Sadanobu reversed many of the commercially-minded policies of his predecessor, Tanuma Okitsugu.
Several domains had begun to cultivate and export high-quality ginseng by the 1840s, including Matsue han and Aizu han; right at the end of the Edo period, in the 1860s, Kumamoto han also began exporting high-quality ginseng.
- Robert Hellyer, Defining Engagement, Harvard University Press (2009), 61.
- Schottenhammer, Angela. "The East Asian maritime world, 1400-1800: Its fabrics of power and dynamics of exchanges - China and her neighbors." in Schottenhammer (ed.) The East Asian maritime world, 1400-1800: Its fabrics of power and dynamics of exchanges. Harrassowitz Verlag (2007), 56-57.
- Hellyer, 68.
- Hellyer, 74-75.
- John Whitney Hall, Tanuma Okitsugu (1719-1788): Forerunner of Modern Japan, Harvard University Press (1955), 78.
- Hellyer, 118.
- Hellyer, 121.