Most of the time, the wasabi you get in a restaurant or buy in a store is fake. It’s actually horseradish that’s colored green. Why? Well, wasabi is a notoriously difficult plant to grow. In fact, it’s considered the most difficult plant in the world to farm commercially. Yet for the past century, the Daio Wasabi Farm in Hokata, Japan, has been growing it successfully with natural spring water from nearby mountains.