In our previous post, we've talked about wasabi served at most sushi restaurants in the US, not being "real" wasabi. There is some fresh wasabi root imported from Japan and very little are available at retail stores. In San Francisco Bay Area, you CAN find some fresh wasabi grown right here locally, in Hal Moon Bay.
They are called: Half Moon Bay Wasabi Company
They are available at Tokyo Fish Market in Albany, some Nijiya Market in San Francisco, San Mateo.
There are some online stores including Frogs Eye Wasabi in Oregon.