Growing Fresh Wasabi

Wasabi Crop was started up by Dr Sean Kitson and his son Zak from where they live in the Orchard County of Armagh, Northern Ireland. The idea of this new company came from Zak when he set out to think about growing rare garden plants. He came across an unusual plant called Wasabia japonica during his research into a possible business venture. 

Subsequently, he discussed his idea with me and when I looked into it I discovered it was a tough plant to cultivate.  To my astonishment, this medicinal herb was mostly grown in Japan and it would be difficult for Zak to achieve his goal.

However, if Zak could grow wasabi, that would be amazing.  Just imagine being the first to grow and sell wasabi on the Ireland of Ireland – it would certainly make the news!

Zak was only 15 years old and began to plan his ideas on how to grow fresh wasabi.  First, he decided the best place to grow it was in a large polytunnel on his field. The Wasabi Crop Growing Facility was constructed by June 2016.

The next challenge was to source native wasabi plants because it is near impossible to get your hands on real wasabi seeds.  If you did manage to obtain wasabi seeds they would more likely turn out to be mustard seeds –as we discovered our peril.  However, we did manage to secure some wasabi plants from a viable source.  After a few months, the wasabi seedlings finally arrived in Northern Ireland and by then, we had decided on how best to grow them.

The next stage for Zak was to harden the fragile wasabi plants by gradually exposing them to the outdoor conditions.  This process was vital to enable the young delicate plants to sustain themselves into a firmer, harder growth.

After several weeks, the wasabi plants were hardy enough to be planted in the polytunnel’s prepared beds.  I think Zak spent a few days planting about 600 in total.

My Passion for growing Wasabi Plants

During the next several months especially going into the winter season and nights drawing in Zak got into a routine looking after these precious wasabi plants. He began to find horticulture interesting and enrolled in an online herb course to understand the science behind growing plants.

As the days and weeks went by, many tasks were performed in our Wasabi Crop Growing Facility as Zak called it.  These tasks involved keeping the weeds away from the growing beds, monitoring and recording the growing facility’s temperature and humidity.

Zak explained to me that wasabi is a wasabi shade-loving plant and in Japan wasabi is grown under black shading cloth in streams and more naturally under the branches of trees.  So inside the polytunnel, we utilised black shading cloth over the wasabi plants. This was unusual because you would think plants would like a lot of sun – but we don’t get much sun in Northern Ireland.  Zak proved this by planting some wasabi in pots outside in direct sunlight and found the leaves were burning.  I suppose this was Zak’s first scientific experiment in horticulture.

Zak working in the polytunnel

Another factor that is important was to aim for an optimum temperature between 6 to 20 degrees Celsius for good crop production. Zak and I discussed the growing medium’s pH when growing wasabi which is essentially best kept in the range of 6-7 units. 

It is also important for these semi-aquatic plants to grow in an environment of high humidity to keep the prized wasabi root moist and not sitting in pools of water which could result in root rot.  Zak came up with the idea to fit an overhead, automated watering system – I thought he was becoming lazy, but this turned out to be a good idea because we could leave the wasabi plants and get on with other jobs.

Over the following several months the crop was doing exceptionally well and Zak continued to monitor the growing medium. He found a mixture of pea shingle, soil and rich compost worked well. The young wasabi plants were also given dilute seaweed which provided the necessary nutrients to produce high-end rhizomes for potential customers.

Today, Zak is the first person on the Island of Island to sell fresh wasabi rhizomes, wasabi plants and even edible flowers.  He tells me the only disadvantage in cultivating wasabi rhizomes is the 2-year wait.  This is how long it took to harvest his first wasabi rhizome, which weighed over 120 grams. 

The great thing about wasabi root is that not only can you consume the rhizome but also the stems and green heart-shaped wasabi leaves. These wasabi leaves and stems can be used to prepare an exciting salad with that extra wasabi kick.  Why not add fresh wasabi to your favourite beverage or grow your own island of Ireland wasabi plants like Zak.

Why Grow Wasabia japonica?

The motivation behind Wasabi Crop is the medicinal properties associated with Wasabia japonica.  This medicinal plant has been found to have both antibacterial and anti-inflammatory benefits for your health.  Enjoy the taste of the island of Ireland wasabi rhizomes and wasabi leaves.

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