Wasabi has been an important ingredient in Japanese cuisine for centuries. Wasabi is also known as Japanese horseradish; its Latin name is Wasabia japonica.
The Honzo Waymo is Japan’s oldest botanical dictionary believed to have been compiled in the year 918. The dictionary included numerous references to wasabi, which was then being used medicinally and was considered an antidote to food poisoning.
The leaf bearing stems (petioles) of the Wasabia japonica plant emerge from the rhizome to a length of 12 to 18 inches and can reach a diameter of up to 40 mm (1 ½ in). They terminate into single, heart shaped leaves that, in optimum conditions, can reach the size of a dinner plate. The leaves and leaf stems (petioles) are quite brittle. Breakage or damage from animals, field workers or mishandling can cause growth to slow and even suspend for periods of time.
Using traditional sawa (water-grown) methods, wasabi can take as much as three years before the rhizomes reach market maturity. Initially, given the right conditions, the perennial plant produces robust top and root growth, reaching approximate knee height (2 feet) with an overall width of about the same. After this establishment phase, the rhizome begins to build and store reproductive nutrients. Rhizomes may reach a size of six to eight inches in eighteen to twenty-four months.
Under optimum conditions, Wasabia japonica will reproduce itself by seed. Since it is highly valued, new planting material is also propagated in laboratories via tissue culture techniques. In commercial wasabi farms, plant stock is further extended by replanting small offshoots which, like with strawberry plants, characteristically occur as Wasabia japonica matures. For more information about the health benefits of Wasabi, see our article.