There is green and white asparagus, but they are exactly the same variety that is grown in different conditions. Green asparagus is grown in the sunlight, while white asparagus is buried in soil before its buds break through the surface, resulting in a white color. Asparagus is believed to have originated somewhere between Southern Europe and Southern Russia and it was first brought to Nagasaki, Japan from Holland at the end of the 18th century. However, this was only for show. The first asparagus was grown in Japan in 1871 when the government of Hokkaido imported seeds from the United States. In 1923, canned white asparagus was made in Iwanai Town, which was the first time in Asia that canned asparagus was produced. In recent years, purple asparagus is also being grown. This variety contains the pigment called anthocyanin.
Hokkaido-grown asparagus appears in stores around May and June and is popular as a vegetable foretelling of early summer. Hokkaido is the number one grower of asparagus in Japan, as it accounts for about 20% of the market. Asparagus is eaten boiled and also tastes great baked or deep fried, making it well suited for a variety of different dishes.
Asparagus is mainly grown in the Kamikawa area and especially in Biei Town and Nayoro City.
■Map / Main producing municipalities
Biei Town, Nayoro City, Nakafurano Town, Bibai City, Higashikagura Town, Furano City, Shimokawa Town, Obihiro City, Bifuka Town, Makkari Village
Asparagus is known as a vegetable of early summer, but the new technique of rikkei cultivation developed in Kyushu’s Saga Prefecture makes it possible to extend the harvest until fall. Conventionally, the growing season ends about 50 to 60 days after it starts, but this technique uses a one-month transition period to extend the harvest until the end of September. Rikkei cultivation is now being used in Hokkaido as well, which makes it possible to attain an even larger yield using the same growing area.
Another new type of growing method called fusekomi cultivation has made it possible to ship white asparagus even during the winter. This involves digging up asparagus stumps grown for about one year in the field and relocating them to a greenhouse where only new buds are harvested from December to March. This asparagus is being grown in Bihoro Town and Shinshinotsu Village, attracting attention as an all new brand.
Asparagus is mainly grown from May to September, with most cultivated outdoors. The peak of the harvest is May to July for outdoor grown asparagus, but March to May for spring buds and June to September for summer buds grown in greenhouses using rikkei cultivation. The recently deployed fusekomi cultivation method makes it possible harvest nearly year round.