Greater burdock has long been used in China as a medicine. It is used as a food in only a few parts of Asia, which includes Japan and Taiwan. Greater burdock is a vegetable essential to Japanese cuisine because of its use in kinpira gobo and in simmered and stir fried dishes. Shell mounds from the Jomon period have confirmed it was eaten during that time as well. Hokkaido yields the third largest amount of greater burdock next to Aomori and Ibaraki prefectures. Hokkaido’s greater burdock is known for its long and narrow shape, and mainly those plants that have soft flesh and a nice aroma are sold in markets and other stores.
Greater burdock is nutritious and very healthy. It contains a particularly large amount of dietary fiber that stimulates the digestive tract and helps alleviate constipation, while also delaying the absorption of sugars and fats and lowering cholesterol. Greater burdock also contains a large amount of polyphenol, an antioxidant. If you place a cut piece of greater burdock in water the water will turn brown. This is the polyphenol seeping out. This is why greater burdock should be prepared without exposing it to water.
Greater burdock is mainly produced in the Tokachi and Abashiri regions because it requires ideal soil conditions to grow.
■Map / Main producing municipalities
Memuro Town, Obihiro City, Makubetsu Town, Koshimizu Town, Abashiri City, Bihoro Town, Toyako Town, Kamishihoro Town, Kiyosato Town, Rusutsu Village
Greater burdock’s roots burrow about one meter into the ground, so soil conditioning is extremely important to cultivating a high quality crop. Greater burdock will not grow in bogs, peatland or places with lots of rocks. The plant does not require much water because it has large leaves that gather moisture. This is why it prefers somewhat dry climates. The Tokachi and Okhotsk areas, which have a cool, dry climate and large amounts of land, are perfect locations to grow greater burdock. However, if greater burdock is continually grown in the same field it will eventually not be able to grow. As a result, every six or seven years other crops need to be grown on the field to replenish the soil.
Greater burdock is harvested between April and November and it is grown exclusively outdoors. The harvest may take place in the autumn or sometimes it is left in the ground for the winter and harvested in the spring.