Sunday, September 12, 2010


Pretty and edible wasabi flowers and buds.
Down at the Tas Farm Gate market nothing inspires conversation at our stall more than the wasabi plants. It is always exciting to find a flavouring we are used to seeing in a processed form, in its raw, living state. Here are my thoughts on its cultivation and uses.

Potted wasabi, note the chook nibbled leaf on the right. Everyone likes wasabi!
Cultivation: Wasabi needs a cool, moist shady spot to thrive. It can be grown successfully in both containers and the garden. For containers, get the best potting mix you can. I've grown it in a 40cm diameter pot with a water reservoir in the bottom and it does really well. You then have the option to move it into the shade at different times of year. In the ground, a well composted, reasonably drained garden soil is great. A South facing garden is best. Don't keep it overly wet, still water will suffocate the roots, but give it some extra water when a hot day is forecast, and even an extra sprinkle in the hottest part of the day to cool it down. Full shade is important, even a glimmer of direct sun on a warm day can make wasabi leaves wilt.

It is irresistible to aphids, slugs and caterpillars. I use a couple of drops of detergent in a spray bottle of water to deter aphids, you can steep a little garlic in the water first which may make it more effective. The other major pest in the late Spring and Summer is the caterpillar of the white cabbage moth. You can keep an eye out and squish them by hand or use Dipel, an organically acceptable bacteria that paralyses the caterpillar but doesn't affect other creatures.

Uses: All parts of the plant are edible. The leaves are lovely shredded in a salad, the stems are delicious raw and can also be pickled in a light vinegar, I'm yet to try this but it's a traditional use in Japan. The flowers are a pretty addition to a salad. Don't over harvest leaves though as this can slow down the formation of the rhizome or 'root'.

In a year to 18 months the rhizome will be ready to harvest. Just scrape a little soil away from the base of the plant and check out the size, it should be about 15-30mm wide. Lift the whole plant and look for the little plantlets that have formed around the crown of the plant. Replant these and keep them moist.

Grate the fresh rhizome and use it fresh with sashimi or sushi. It's supposed to be best grated on a sharkskin grater. I would love one of these, but in its absence I make do with a fine microplane. This paste is best consumed soon after grating. It is gentler, sweeter and more complex in flavour, and paler in colour than the fake, bright green stuff you get in a tube, the two substances are really not alike at all.
It will keep in a ziplock bag in the fridge for a couple of weeks, and can be peeled and grated a little at a time.

Please get in touch if you'd like me to put a plant aside for you, they are a bit scarce here at the moment, but there are more getting established in their little pots as I write.


  1. Planting mine today Paulette. Can't wait to harvest it! Thanks for the informative post.

  2. Thankyou for the information, I might give it a miss then as I don't reckon it will do well up here. I wont even use soapy water on my aphids as I don't want to accidentally get my predators.I grow random sacrificial kale plants especially for the aphids. I have learned from 25 years of organic gardening that If I just leave things alone they sort themselves out, But if the wasabi is irresistible to slugs and caterpillars as well I will leave it alone and buy something from you that is a bit tougher. I am looking forward to seeing you at the MOMA market tomorrow. cheers Kim