In Japan and Okinawa, the beloved sweet potato is considered the taste of autumn. Rich in nutrition such as starch, sugar, fiber, and vitamin C, this root vegetable is popular for those seeking a healthy way to satisfy their sweet tooth.
You’ll find that “sweet potato” goes by many names here, including satsumaimo (which means potato of Satsuma), karaimo (Chinse potato), kansho (sweet potato), Ryukyuimo (Ryukyu’s potato), or Noguniimo. The names for sweet potatoes and the crop itself are deeply rooted in the history of Okinawa and Japan.
These delicious purple-skin and starchy-sweet root vegetables first arrived in 1605 in Okinawa during the Ryukyu Kingdom (1429 – 1879), according to Kadena Town. Noguni Sokan, a government official from Noguni Village (part of present-day Kadena Town), is credited with bringing and cultivating sweet potatoes from Fujian of Ming (present-day China).
Soon, neighboring villages on Okinawa would receive saplings and start to cultivate their own crops of sweet potato. Shinjo Gima, who governed Gima Village, now known as a part of Naha, was the one who helped accelerate the spread after studying the crop and finding that it fit in with the island climate, could be harvested every 5 to six months and, as a bonus, had a good taste.
In 15 years, sweet potato spread across the island and soon could also be found on the mainland.
As early as 1611, sweet potatoes appeared in Satsuma Domain, a present from King Sho Nei Ryukyu, who reigned from 1589 to 1620. Then, in 1615, sweet potatoes arrived in Nagasaki Prefecture with the help of the “English Samurai” William Adams, the first British person to come to Japan. Adams sent a crop he found during port call in Naha to Richard Cocks, director of the British East India Company’s outpost in Hirado at the time.
Cocks’ diary notes that he received a bag of sweet potatoes from William Adams on June 2 of 1615. Around that time, he also received another pack of the root vegetables from William Eaton, another member of the company, who was visiting Ryukyu. Cocks planted the crops in a garden, the first documented cultivation of sweet potatoes in the country, according to Hirado City.
In 1698, Hisamoto Tanegashima, a lord of Tanegashima island in Satsuma domain, received a basket of sweet potatoes from King Shotei of Ryukyu, who reigned from 1669 to 1709. Then the Lord ordered his subordinate to cultivate the crop.
By 1735, the Satsuma Domain’s sweet potatoes reached what is now modern-day Makuhari in Chiba Prefecture. The crop was commissioned to scholar Konyo Aoki by Yoshimune Tokugawa, the eighth shogun of the Tokugawa, as a means to fight off famine. From the 17 sweet potatoes, Aoki succeeded in harvesting about 500 liters of the crop, according to Chiba Prefecture.
Later, sweet potatoes would continue to be the go-to crop when famine struck in the 18th and 19th centuries, then again during the food shortages pre- and post-WWII (1939-1945).
Though today, Japan is in “hoshoku no jidai”, or an era of food satiation and without threat of famine, the love of sweet potatoes continues. So, next time you enjoy a steamed sweet potato from your local grocer, remember this simple, delicious root is steeped in rich history, too!