Wasabia japonica WASABI (plant)

Wasabi, Japanese horseradish, also known by its botanical name Wasabia japonica, is a perennial and hardy plant from the Brassicaceae family. It can reach a height of 20 to 30 cm at maturity. It is native to Japan but also thrives very well on the European continent.

The dark green edible leaves of the Japanese horseradish are thick and round in shape.

Wasabi seeds for sowing, from Eutrema japonicum, are small, thin, elongated, and black. They usually ripen at the end of May, just after flowering. It is necessary to sow them quickly in a seedling starting mix and then stratify them to achieve an excellent germination rate. To obtain viable seeds, it is recommended to plant them in open ground to encourage rapid and natural pollination.

Its flowers are white and small, often used as a decorative garnish in Japanese cuisine.

Its roots are long, thick, and greenish-white in color.

- Its various uses:

A Treasure of Japanese Cuisine

Genuine Wasabi is a demanding plant whose fresh rhizome offers a unique spicy heat, much more subtle and aromatic than chili.
By growing your own specimens from Ethnoplants' quality plants, you gain access to the original flavor of this luxury condiment, far from industrial imitations based on horseradish and green dyes.

Subtle Flavors and Uses of the Plant

Unlike classic pastes, freshly grated wasabi releases a volatile pungency that fades to reveal a refined vegetal sweetness.
All parts of the plant, such as the leaves, flowers, and roots, are edible, allowing you to create artisanal sauces and condiments of incomparable finesse to elevate your sashimi and fish dishes.

- Cultivation and planting:

• Transplant the plant into a 1 to 3-liter pot with a mixture of potting soil and clay pebbles, or directly into the ground.
• Water it copiously during planting.
• Place the pot in a shady and cool corner.

Be careful of summers that are too hot; it really fears excessive heatwaves.

- Soil type, substrate:

It needs a slightly acidic pH soil, rich in organic matter, and well-aerated ground. Sand can also be added to the mix, but in very small quantities for its draining effect.

- Watering / irrigation:

Japanese horseradish grows in a relatively humid and cool environment. For watering, twice a week is sufficient; never let water stagnate in the saucers (risk of root mold).

- Exposure / sunlight:

It adapts to all kinds of light but prefers shaded locations. It is essential to acclimate it when moving it from one exposure to another. Regarding artificial lights for indoor cultivation, horticultural neon lights or MH lamps are preferred.

- Hardiness / temperatures:

Its growth temperature ranges from 10 to 20°C. Beware of heatstroke when temperatures rise above 30°C. It is particularly resistant to very low negative temperatures. Its USDA hardiness zone is 7.

- Multiplication:

There are two ways to reproduce it: either by sowing seeds in the spring or by dividing the base of the plant throughout the year.

- Pests and diseases:

Slugs and snails unfortunately love its leaves.

- Maintenance:

Be sure to remove dead leaves that turn yellow at the base of the plant. Add slow-release fertilizer after 9 months.

This article was written by Julien on 07/20/2026.