The Art of Growing Wasabi

When talking about Japanese cuisine, one of the most quintessential foods that come to mind would be wasabi. Even though wasabi is just as integral to eating sushi as sushi itself, it might come as a surprise to many as being one of the most challenging herbs to cultivate due to a variety of factors. Given the wasabi’s specific environmental needs, a propensity to acquiring diseases and requiring almost two years to fully mature, it’s no wonder that a less-than-optimal condition for growing wasabi would prove to be difficult.

Regardless of all that, there are still plenty of wasabi enthusiasts that can’t get enough growing it; resulting in the compilation of this (hopefully comprehensive) guide for all your reading pleasure.

The Basics of Wasabi 101

Wasabi or Wasabi Japonica refers to the Japanese horseradish and belongs to the family Brassicaceae. It’s a highly profitable plant, similar to that of harvesting lavender. 

What wasabi essentially is, is a paste prepared from the plucked rhizomes on the ground. This wasabi cultivated from these wasabi rhizomes is typically what you’d expect to be served in every Japanese household and restaurants. The aromaticness and strong, spicy taste complement sushi well.

Reasons to Grow Wasabi

  1. Freshly-grated wasabi is a hot favorite among top chefs. This means that your locally homegrown wasabi could potentially sell for a respectably high price from the right buyers.
  2. Homegrown wasabi is obviously fresher than store-bought wasabi. This is just a fact. Hence, your wasabi would naturally produce a stronger, more refreshing flavor when being crushed to produce the paste.
  3. Wasabi bestows a lot of health benefits to regular consumers; from reducing the rates of cancerous cell growth and risks of cardiovascular diseases to treating arthritic joint pains and containing antibacterial properties; the medicinal properties of wasabi seem too good to be true.

Becoming an Expert Wasabi Farmer

If it isn’t already evident by now, wasabi tends to be a picky plant to cultivate. There are many different factors in the consideration of wasabi farming.

Fundamentally, there are two varieties of wasabi to choose from; however, there are only two types of wasabi plants to grow from seeds — the Duruma and Mazuma. You can either grow them in pots or in your backyard. Moreover, a small irrigation project is recommended to ensure that your soil doesn’t get overly-saturated with water which might cause fungal growth on the roots of your wasabi shoots, resulting in decomposition.

No plant would thrive well without the right temperature, humidity, and water conditions; your wasabi plant is no different. In fact, it might be slightly more complicated caring for it due to specific environmental demands:

  • Ideal temperature range: 7°C — 21°C. Wasabi plants aren’t too adaptable to wide temperature fluctuations.
  • Requires a balanced pH level of between 6 and 7
  • Wasabi doesn’t require a greenhouse to grow in, however, there should still be decent shelter provided. 
  • No direct sunlight; wild wasabi typically grows in forested floors.
  • The soil should be about 25cm deep. This can be done using a roto-tiller or shovel. Next, add compost to fertilize the soil, ensuring it’s rich in nutrients for the wasabi seeds to germinate in.

But When is the Best Time for Planting Wasabi?

  • Plant your wasabi within two days of obtaining them.
  • Ensure to submerge them in water for a decent period before planting them.
  • Garden: Your wasabi seeds should be about two to three inches apart from each other.

Pot: Ensure the pot is 30x30cm in dimensions. Pot each plant roughly 10cm apart from each other. 

  • Experiment with different soil combinations such as potting soil, vermiculite, and perlite.
  • Water your wasabi seeds decently well because wasabi is semi-aquatic in nature.
  • However, do make sure to drain your soil well before applying fertilizer to it. 
  • Best season to plant wasabi: Summer/Autumn
Tools needed

Now that you know the plan, it’s time to ‘tool (suit) up’. You’ll need:

  • Tarp
  • Fertilizer 
  • Distilled water
  • Roto-tiller and shovel
  • Garden/greenhouse/pot
  • Your precious wasabi seeds

Wasabi TLC

  1. Fertilizer: Just like how humans need vitamins to promote health and improve their immunity, plants need fertilizer too. Follow the instructions as given on the fertilizer bag. However, be mindful of the pH level in your soil and adhere to the wasabi pH recommendations of 6 to 7 accordingly. Too much fertilizer could affect the pH level.
  2. Weeding: Weed your wasabi plants regularly. The presence of weeds not only steals nutrients from your wasabi necessary for its growth, but it also facilitates the spread of diseases more rapidly. Overall, the environment of your wasabi would be compromised.
  3. Winter care: Even though wasabi in the rhizomes can survive in freezing temperatures below -5°C, you’d still want to take the necessary precautions of protecting your wasabi plants during the cold season. Cover your wasabi with a thick cloth to prevent it from freezing over.
  4. Patience is a virtue: Growing wasabi will not happen overnight. It takes a lot of time and patience (of two years!) to ultimately complete its growth cycle from a baby shoot to a fully-matured adult plant. 

Extra Wasabi TLC (Fully Matured)

One of the good things about growing wasabi is that even though the preparation stages can be a bit tiresome, once all the fundamentals are accounted for, you can sit back, relax and watch your little wasabi seedlings flourish. They are tough to grow because of the duration and certain surrounding conditions, but they are hardy plants nonetheless! Pests and insects tend to not disturb them too much. Occasionally you might run into a few aphids here and there (along with mildew), but they’re not too much of a concern. At most, they’d damage a couple of leaves.

  • Once your wasabi plant is an adult, ensure that you still maintain the moisture levels of your soil and fertilize it sufficiently (every quarterly) with a layer of compost or manure rich in sulfur. 
  • If some leaves begin to yellow, try growing a taller plant beside the wasabi plant. If not, place a piece of shade cloth over it if the sunlight seems too harsh.
  • Remove any wilting leaves, stems or weeds. Check for pests like snails or slugs that prefer damp and dark conditions like the wasabi plant.

Harvest Time!

When your wasabi plant has grown to almost two feet tall and wide, it’s completely grown. You can also tell by the presence of large heart-shaped leaves. Its leaves will continue to live on for the next six months till winter.

To begin the harvesting process, first, dig out the rhizomes to check if it’s truly ready for harvest. Try your best to not accidentally cut them. Next, place the wasabi seeds at comfortable distances from one another (roughly 330cm apart). Some additional precautions to note would include:

  • Do NOT remove the plants. The plants will self-seed themselves, thus you won’t need to re-purchase more wasabi seeds to repeat the arduous cultivation process.
  • Ensure the rhizomes are kept neat and clean; also remove their leaves
  • Preserve the rhizomes in a cold environment — either your refrigerator or the freezer compartment will do. This will prolong their shelf-life in creating wasabi paste.
  • Cutting rhizomes prematurely may result in the loss of aroma.


Wasabi farming is a very rewarding process if you stick through it completely. Because it takes two years for one growth cycle to finish, you’ll definitely bond and feel personally attached to your wasabi plant, believe it or not. It’s a responsibility not to be taken lightly. However, if you treat it with the necessary tender, loving care that every living thing needs, you’ll feel fulfilled by the end of each harvest. So what’s stopping you from growing your very own wasabi today?


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