Japanese Wasabi - Eutrema japonicum

The Japanese Wasabi or Japanese Horseradish (Eutrema japonicum) is a perennial plant that is cultivated for its grated root, similar to horseradish, but also for its leaves. With a strong and spicy flavor, wasabi adds fragrance to many Japanese specialties such as sushi and the eponymous spicy sauce. Both the root and leaves can be consumed raw. Successfully growing Wasabi is delicate, as the plant cannot tolerate temperatures below 15°C (59°F) or above 20°C (68°F), direct sunlight, and its foliage attracts slugs. The root is harvested after 2 to 3 years of cultivation, when shoots appear near the plant's stump. These shoots are then replanted in a pot to obtain new plants.

The Japanese Wasabi belongs to the Brassicaceae family, and is a relative of mustard and horseradish. It is native to Japan, as well as the Russian islands of Sakhalin, where it grows along rivers in humid mountainous areas, under a very temperate climate, unaffected by both freezing temperatures and heatwaves. The plant develops thin brown stems that bear large heart-shaped leaves with prominent veins, measuring up to 20 cm (8in) in diameter. The tip of each vein has a small rounded protuberance resembling a pearl. Young leaves are bronze-green to purplish in color, while adult leaves are a more vibrant green. This lush foliage persists throughout the year. The spring flowering takes the form of small white to pinkish flowers.

In cuisine: The finely grated root of Japanese wasabi is used to make the green-colored spicy sauce called Wasabi, but this condiment also enhances sushi, meat or fish dishes, soups, and rice. Modern cuisine also uses it to flavor certain pastries. The stems and leaves can be enjoyed as green vegetables, stir-fried in a wok, or even deep-fried in tempura. It is also a recognized medicinal plant in Asian pharmacopoeia.

Harvesting: Harvest the leaves as needed, they can be used raw or cooked, and their flavor is milder than that of the root. Harvest the root after 2 to 3 years of cultivation, when it measures approximately 10 cm (4in) in length and 3 cm (1in) in diameter. Grate the root very finely as needed, as its aroma is highly volatile!

Storage: Wrap the wasabi root in a damp cloth and place it in an open plastic bag to be stored in the vegetable compartment of the refrigerator. Change the damp cloth every two days. Cut off any new shoots that may reappear to avoid exhausting the root.

Cultivation tips: Japanese wasabi is a plant that prefers shade, humid wooded environments, and a temperature that oscillates around 15°C (59°F) both in summer and winter. Cultivate it in a pot, protected from direct sunlight, in high-quality soil that remains slightly moist. Do not use a saucer under the pot to avoid stagnant water that could cause the root to rot. Consider placing a layer of clay pebbles at the bottom of the pot for drainage.