I don't know where in the forums to put this plant--I can't believe I couldn't find threads on it already.



I've been growing wasabi, mostly in aquaponics systems, for a couple years now, and decided to take it a bit more seriously this year. For me the principle obstacle has been heat (but they also don't like a freeze). I've managed to keep some growing in the greenhouse for a long time now, and it seems that cool water temperatures go a long ways toward mitigating high air temperatures. These plants are also, like many brassicaceae, highly susceptible to aphids.

I'll be up front in saying that I'm messing about with these, like I do so many other plants, for my own amusement. We'll see what comes out of my efforts in a couple more years, but I'm patient. That said, I run a wholesale plant nursery business, so I employ quarantine protocols, IPM, climate monitoring, mass production methodologies, and strict observation and record keeping, as in all of my plant projects.

Here are my latest trials, on extra deep water tables (~1" of water) with some plants each in coarse media, fine media, and classic peat-based propagation mix. I have Daruma, Mazuma, Green Thumb, and wild strains of wasabi plants, under two different artificial lighting protocols. For this first phase (~5 months) I will not be varying temperature between the groups, but I plan to do a split after that with cooler and warmer conditions. Temperatures in the current setup swing from 60F (~15C) at night to 77F (25C) during the day.

In six months the plan is to split the group, with one half moving out into warmer temperatures and less absolute control over conditions (shadehouse), and the other remaining indoors. At that time we'll also be evaluating transplanting protocols, but that will depend a bit on the observed growth. In all, the two year plan is quite involved, but there are many forks it could take based on observations, and those criteria are many. There are also many things I'd like to explore with these plants, including propagation and crosses, and the interplay between nutrients, temperature, light, and media.

I'm still making adjustments to the tables, but here's an early shot:



The plants in loose media have produced more young leaves, including side shoot leaves, since they were transplanted, while those in peat mix have better enlarged the fewer leaves that they have. I have my doubts about the peat mix, but plants using it and sunk into the aquaponic tables in the green house have been amazingly tough.

One thing I have never tried to grow. It is an herb. Wasabia japonica or Eutrema wasabi. Similar to horseradish which is more often used as a substitute.

Paul, that's a very interesting project! I think this past season (or possibly the year before?) was the first time I ever saw Wasabi offered in the garden catalogs that I get (seemingly hundreds of them...). Is it the roots that you use, like horseradish?

The stem, often called the rhizome because it roots and shoots adventitiously and can sometimes be found below the water line, is grated finely to make a paste. However, the leaves are quite good as well, and there are several leaf preparations that can be done to bring out the flavors more. I think wasabi's scarcity both as a plant and as food is due to its slow growth rate (18-24 months to harvest the stems) and its need for wet, mild (Japan-like) growing conditions.

https://www.researchgate.net/p...

Interesting!

Hi Paul, I was looking for information regarding wasabi cultivation and found your post. I'm curious how your experiment evolved and what you found out in the last years?

I'm not the best source for generalized wasabi growing information, though I could dig up some of the sources I've used, if you want. The experiment above has wrapped up for now and wasabi cultivation has moved out to the greenhouse. I have been putting together some special purpose systems to try growing wasabi outdoors in the heat this year, and will try to remember to post about that if I can get them online.

Some things I learned from the above iteration:

Nighttime lows are more important than daytime highs. They can handle more heat than I expected as long as it cools off at night. Room temperature is too warm for this, and preliminary testing indicates nighttimes shouldn't get much above the 50s (F), though I need more data here.

Plants in coarser media did better initially (1/2" expanded shale), but were eventually overtaken by plants in finer media(1/4"), with more soil-like media (coir and soil-less mixes) being most successful long-term in my aquaponics systems. Other factors may have affected this, so I wouldn't take it as gospel, but I will be using finer media in later experiments. A notable counter example are a couple of wasabi plants that have been in my 3/4" expanded shale flood and drain siphon bed for 2 1/2 years now through all kinds of temperatures, but these have failed to grow very fast despite their tenacity, and I wouldn't rate their growing conditions as favorable.

Wasabi wants even less light than I thought. My lighting systems weren't calibrated for going as low as the plants wanted, and I had some early damage as a result. Like many plants, they do seem to tolerate more light at lower temperatures.

When temperatures are high, drier plants can go fully dormant, but the ones in my aquaponic system struggled and died under similar water/media and air temperatures. Outdoors, dormant plants in Pro-Mix sitting on a 1/2" water table remained dormant through 110F highs in the shade, and then grew vigorously in the winter (still on the water table). Dormancy is not ideal for production of a long-growing crop, and may adversely affect the product, but does open up possibilities for saving plants in the (inevitable) event of things going wrong.

I had a little bit of powdery mildew set in at one point, but a few applications of dilute peroxide cleared it right up. I think it wouldn't have been a problem with more air movement.

Hi, Paul 😀
Interesting ! I've allways thought that, Wasabi, was nothing more than horseradish.
Now, I'll check the ingredients label, to see, if it's the real McCoy.

Sounds like a real pain to grow.
Is it the root or leaves, that are eaten ?

Good Luck on your venture. 👍

😎😎😎

Quite certain it is of Japanese origin and is indeed "their" version of horseradish. While I am not a fan of horseradish, I do love Wasabi, but can't remember what dish I use it on? Sparingly, until your nose starts to run! LOL. What's that dish????

It's the stem that is ground finely on sharkskin into a paste just before eating it, usually with sushi. It is in the mustard family, but not much like horseradish as a plant. The leaves, however, are also tasty, as I mentioned above.

Just some photos. Currently growing in 3 gallon fabric pots, in a basin to retain moisture, under plastic in the shade.

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I'm curious about the leaves. Do they taste like the root or something else?

Like a mild mustard green, to me. I haven't tasted the stem yet.

That froggy's cute!

Cute frog, we don't have them around here. But I used to grow horseradish, they can be a pest if one is not careful.

Found this site had some good info on wasabi

http://www.thewasabistore.com/...

Hi PSA,

Can you take full pictures of your Wasabi Pot? do you have all 3 varieties (Mazuma, Daruma and Green Thumb)? I wonder what Green Thumb look like. my wasabi plant look like it happy under grow light. which I think it does need light cause I have 1 near the window with bright light, but no new grow at all.

Aside from grated stem, and leaves, the flowers are also relished in spring, if you have access to them, very mild, but need a very short cooking, or you will loose the taste.

Strangely, I failed to take any pictures of the wasabi this winter and spring, except for the close ups. Right now they're struggling mightily with the hot weather and losing lots of leaves. Mazuma is doing best with the heat and Daruma worst, with Green Thumb somewhere in between. Green Thumb has smaller leaves in my plants, but the offsets establish faster. Wasabi grows best for me below ~55 degrees F, and it stalls out entirely above 65. I keep them as moist and humid as I can in our desert climate. I've had several plans for heavy-duty swamp cooling for them, but no time to set it up.

My indoor temps are too hot for me to grow wasabi without extra cooling for them.

Great thread.