PNW Landscape Plant Guide

brought to you by the plant geeks at Calendula Farm

Japanese Horseradish a.k.a. Wasabi

By now, most people who enjoy sushi know that the little wad of green paste that comes with sashimi or rolls is not true wasabi, but instead, a blend of common horseradish, mustard, and green food dye. Well, you can now become a foodie elitist and grow & grind your own pure wasabi. Ok, you don’t need to be elitist about it, but a little smugness is still acceptable.

Wasabi grows similarly to and is related to common horseradish (which has its own fine attributes) except wasabi needs shade and regular watering. Common horseradish is the opposite. It doesn’t care if it gets watered and can soak up sun all day long. In both cases, the root is harvested after about two years of growth. The whole plant is dug up and there will be a large central taproot and lots of smaller fingerling roots. With Wasabi, the plant looks like a tight cluster or colony of smaller plantlets around a larger ‘mother’ plant. Keep the large ‘mother’ plant root and replant the smaller ones for next year’s harvest. Once you start this process, you should have a constant supply of Wasabi.

If you want to be a pure traditionalist, you will trim the extra rootlets off the main one and grind the prize root on sharkskin which turns it into a fine paste. Or you can purchase a manufactured Wasabi grinding board and get the job done less expensively.

The cool thing most people don’t realize is that when Wasabi is happy, it grows like crazy and you can continually harvest the leaves to include in salads. They have the same complex flavor of the ground root but without the flash of hot in the sinuses.

In the wild, Wasabi grows at the top of stream banks in forests with its roots dangling into the moving cool water. Commercial growers simulate this for high production, but you don’t need to. Just grow it in shade and keep it evenly moist. Pacific Northwest climate 8 months of the year is its sweet spot.