I am a great fan of wasabi, so in the summer of 2008, I planted "starts" in the garden of my summer home in British Columbia, near Puget Sound. Wasabi is notoriously difficult to grow - it requires plenty of water; shade to protect the leaves from sunburn; just the right mix of minerals and other soil nutrients; and two full years to reach usable size. I got the starts from wasabia.com, the main wasabi cultivators in the Northwest U.S. I love to eat wasabi in all forms, and make a point of seeking it out whenever I travel to Japan.
This is the whole wasabi, fresh from the garden. The Japanese use all parts of the plant - they grate the root to form a condiment paste for sushi, and pickle the leaves to make a spicy dish called wasabi-zuke.
From Summer Gardening in British Columbia