Grown for its remarkable rhizome, Eutrema japonicum (Wasabi) is a semi-aquatic perennial forming a thick rhizome and boasting long-stemmed, rounded, kidney-shaped green leaves. Elegant 4-petaled white flowers are carried above the foliage. All parts of this Japan native are edible. Both leaves and flowers can be eaten (cooked) while you wait for the rhizome to develop to harvest. It takes about 15-24 months to produce a good fleshy rhizome. Dig up the rhizome in the second and third year and use it fresh at any time. Finely grated, it is prepared into a fresh green paste which is used as a condiment in Japan. It may be stored in a sealed plastic bag in the refrigerator for up to 2 months. Predominantly shade loving with high moisture needs, Wasabi is suitable for bogs and water gardens. The best quality rhizomes are produced from plants growing in semi-shade in clear running spring water at a temperature between 50-55°F (10-13°C). Wasabi is intolerant of heat and will stop growing in temperatures over 80°F (26°C).

• Grows up to 6-12 in. tall (15-30 cm) and 6-9 in. wide (15-22 cm).
• Performs best in humus-rich, consistently moist soils in partial shade. Do not let the soil dry out between waterings. Full shade is tolerated.
• Keep an eye out for leaf spot, root rot, rhizome rot and petiole blight.
• Propagate by seed sown in spring or by division.
• Native to eastern Asia, Japan.