Skip to Content

11 Of The Most Amazing Facts About Growing Wasabi You Never Knew

Notoriously Demanding

We are most familiar with wasabi in the form of the green paste you would find beside sushi when you dine at your favorite Japanese restaurant. And if you regularly enjoy Japanese cuisine, Wasabi may have ben, your constant condiment.

However, experts and gardeners alike claim that Wasabia Japonica is one of the rarest and most difficult plants to grow and nurture.

Growing Wasabi

Therefore, the few who are successful at growing wasabi sell this rare and demanding plant at extremely high prices. Chiefly, the horticultural world handles wasabi supplies almost as carefully as they would gold.

What makes wasabi so hard to grow? And are you thinking about taking on the wasabi growing challenge? Here are 11 amazing facts about growing wasabi you may not know yet and what is involved in nurturing this finicky vegetable.

Growing Wasabi

11 Amazing Facts About Growing Wasabi

1. It’s not a Root Crop

Although the entire plant is edible, the part of the wasabi that the culinary world uses to make paste is its thick stem that grows above ground.

Hence, it is a common misconception that wasabi paste comes from the roots of the wasabi plant. This is in contrast with root crops such as carrots as well as ginger, which is a rhizome.

When farmers harvest their wasabi, they would uproot the plant, cut off the long roots, and then separate the thickened stem from the leaves. Subsequently, you would make wasabi paste by grating the stem. Meanwhile, many would usually fry the leaves into chips or take them raw as a salad vegetable.

2. Wasabia Japonica are Extremely Finicky

For wasabi to thrive, they would need the ideal balance of water quality, sunlight, temperature, and fertile soil. Therefore, you will only find naturally-growing wasabi in certain parts of the world that meet its ideal climate.

For instance, the perennial wasabi is native to parts of northern Japan where they grow beside streams under the cool shades of the forest canopy.

The only other parts of the world that have similar environments are as rare as the vegetable itself.

3. Wasabi Matures only after 2 years

Growing Wasabi 1

As if caring for the wasabi wasn’t enough, you’ll also need to wait at least 24 months to find out if you are successful at growing a healthy wasabi plant that is ready for harvest.

After 24 months, the thickened stem of the wasabi usually grows to about 4-6 inches and is at its optimum flavor and spiciness.

4. You’re Probably not Eating Real Wasabi

What then of the green paste you would often enjoy with your weekly sashimi?

Growing Wasabi 2

Restaurants would often use horseradish since is from the same family as wasabi. With horseradish, they would add mustard and some food coloring for that familiar green color.

At best, premium restaurants may mix a small amount of genuine wasabi to horseradish. At worst, though, the pungent paste that you’re taking with your tuna may just be a sad mix of artificial flavoring and extenders.

Why won’t restaurants just get their hands on real wasabi stems?

5. A Kilogram of Wasabi may Cost a Minimum of $200

Hard to grow and exceedingly rare, genuine wasabi fetches a very high price. It’s no wonder then that many try to cultivate this plant as success will mean a very lucrative business. Few, however, are successful at overcoming the wasabi growing challenge.

6. Real Wasabi Quickly Loses Its Heat

Another reason for wasabi’s hefty price tag is its perishable flavor. Once you grate or shave the wasabi stem, its flavor will quickly diminish in less than thirty minutes and will completely disappear after several hours.

The effervescent nature of wasabi’s taste is also why many would choose to dry and grind wasabi into a fine powder to extend the flavor for as long as possible. You would then need to add water to the powder to make a paste.

Accepting the Challenge

Do you think you have the patience and can succeed where many have failed? Here are more facts about growing wasabi.

7. You can order Wasabi Starters Online

Online stores may have both seeds and starter stems available. However, I would recommend getting a starter stem for maximum chances of success. Afterward, you may commence by creating the perfect environment for your wasabi.

Ultimately, Wasabi will only thrive…

8. In Rich, Moist, And Free-Draining Soil

You must thoroughly till, aerate, and enrich your soil if you will have any chances of starting wasabi. The demanding plant requires wet but not soaked ground with high sulfur content and a pH level of 6-7. Consider also, further supplementation with sulfur fertilizers.

9. Under Shade

Wasabi plants will quickly wither under direct sunlight. Therefore, make sure you protect your wasabi plant from a full day’s sun. You can consider planting wasabi underneath the shade of a tall tree or a homemade canopy.

10. Withfrequent Cool Watering

How finicky can wasabi get? It actually requires a continuous bath of 45-55°F (7-13°C). Take care not to soak the plant or its soil bed. Instead, keep them moist through regular misting.

11. If Given A Lot Of Space& Kept Pest-Free

Growing Wasabi

Finally, make sure to space wasabi plants at least 12-inches apart and routinely inspect for any pests.


Heed this facts and tips, and maybe, just maybe, you can also grow your own wasabi. Nevertheless, I wish you happy gardening!


Patrick Brown

Saturday 7th of September 2019

Hi Quang, Is there a difference in flavour between awa ( soil based wasabi and sawa ( water based) wasabi?

I live in Ireland which is 12 degrees and damp most of the year with little strong sunlight.

Are these conditions not similar to the IZU region of Japan?

Thank you for reading the question,

Many thanks,

Patrick Brown