Wasabi (Eutrema japonicum)

Real, freshly grated heat that promises a first-class culinary experience? Cultivating this fascinating plant makes the heart of every gourmet gardener beat faster. Wasabi (Eutrema japonicum), also known as Japanese horseradish, is a botanical and culinary specialty. It impresses not only as an attractive structural plant for shaded beds but, above all, as an absolute star in the kitchen. True wasabi is a rarity, far removed from the commercially available green paste in a tube. Anyone looking for the ultimate, authentic taste experience for their home garden and an exciting crop will find it here.

Scope of delivery: Robust plants in a 9cm pot for €6.20 each or young plants in a 7cm pot for €4.60 each.

Growth & Appearance

• Lifespan: Perennial and hardy.

• Growth height: Reaches a compact height of about 30 to 60 cm, depending on location.

• Habit: Grows as a perennial, herbaceous plant. The rich green, heart-shaped leaves sit on long stalks. Over time, the plant forms the coveted, thickened rhizome (rootstock) at the base.

• Blossom: In spring (from about March/April), delicate white to slightly pink inflorescences emerge on loose panicles.

• Ingredients: Unlike chili peppers, which burn the mouth, wasabi is rich in specific mustard oil glycosides (isothiocyanates). These provide the characteristic, intense heat that immediately rises into the nose but dissipates pleasantly after a short time.

Good to know

• Other names: Japanese horseradish or water horseradish.

• Origin & History: It is native to the cool, shady mountain regions of Japan. There, wild wasabi grows semi-submerged along the banks of clear, flowing mountain streams.

• Curiosities from around the world: Did you know that over 90% of the "wasabi" served in restaurants worldwide is not real wasabi? It is usually a mixture of ordinary horseradish, mustard, and green food coloring. Real wasabi is a valuable luxury item because its cultivation is considered demanding. Traditionally, the fresh rhizome is processed into a fine paste using circular motions on a special sharkskin grater (oroshigane) to release the full aroma.

Usage

• Culinary & Kitchen: As a fascinating plant for culinary gardeners, wasabi offers double the benefits. The widely known, legendary spice is grated from the plant's mature rhizome. What many don't know: The large, heart-shaped leaves and crisp stems also have a slightly spicy and extremely tasty flavor, making them excellent for use in the kitchen.

Location, Care & other important things

• Location: Shady to partially shaded, necessarily cool and sheltered from the wind. The plant cannot tolerate direct midday sun.

• Care: Wasabi is thirsty! The nutrient-rich substrate should be kept constantly moist (however, waterlogging without oxygen should be avoided). A spot at the edge of a pond is ideal for mimicking the natural conditions of Japanese streams.

• Overwintering: The plant is surprisingly robust. My own experience shows: when kept in a pot, it proves frost-resistant down to below -10°C.

Planting & Location

• Outdoors: Can be planted from spring to autumn.

• Tip for cultivation: Since not everyone has a cool stream in their garden, pot cultivation is an excellent alternative. Choose a sufficiently large pot, use humus-rich, nutrient-dense soil, and place the container in the cool shade (e.g., under trees or on the north side of the house). On hot summer days, it must be watered regularly and thoroughly.

Wasabi in the kitchen (DIY)

Since growing a thick rhizome requires patience (often 1.5 to 2 years), you can perfectly bridge the waiting time by using the above-ground parts of the plant in your culinary creations.

Using spicy Wasabi leaves:

• As a salad highlight: Harvest young, tender leaves. They have a crisp texture and a pleasant, mild heat. Simply wash, cut into strips, and toss into mixed leaf salads.

• Pickled stems (Sanbaizu): The leaf stalks can be cut into fine rings and marinated briefly in a mixture of soy sauce, rice vinegar, and a little sugar. A fantastic, fresh side dish for fish or rice dishes.

• Pesto with a kick: Puree the wasabi leaves with high-quality oil, toasted nuts, and a bit of Parmesan to create an extraordinary pesto that adds an exciting Asian note to any pasta dish.