To protect the Wasabi plant from slugs and snails, any metaldehyde type slug bait should work well. After approximately 18 months to 2 years, the Wasabi plants will be ready for harvest. These can be used for replanting. Wash the plants thoroughly and remove any dead or dying leaves. Break the roots off at the rhizome and cut off the stems and leaves.
Many people use the leaves as a garnish or even as a salad item.
Scrub the main rhizome to remove any soil and debris. Grate, using a fine grater in a circular motion. After grating, chop the fresh Wasabi with the back side of a knife. This will release more of the flavor. Compress the fresh Wasabi into a ball and let stand for five to ten minutes at room temperature so that the sweetness and heat have time to develop.