If you are a fan of Japanese food and a lover of sushi, you probably know what wasabi is. It's that green, spicy condiment. But what a lot of people don't realize is that the wasabi you normally eat with your sushi probably isn't "real" wasabi at all.
Actual, wasabi is a very delicate plant related to cabbages, horseradish, and mustard. It is not easy to cultivate. It requires clean running water and a very specific set of growing conditions. Because of this, real wasabi is very expensive - so when you're chowing down at your favourite sushi joint, you're likely getting a mixture of horseradish, mustard, starch, and green food colouring.
by lazythunk - Wasabi Root Shavings
Despite the difficulty in cultivating the wasabi plant, people in Japan have been growing and harvesting it for over 400 years. Use of the plant dates back much further than that. It has been used for thousands of years as medicine for its sterilizing effects and its ability to expel parasites. There are very few places in the world that are actually suitable for large scale cultivation of wasabi and even when conditions are perfect it is difficult to grow. Still, sushi is what most of us think of when we hear the word wasabi.
Wasabi is grown primarily in three regions in Japan: the Izu peninsula, Nagano prefecture, and Iwate prefecture. There are also a few companies in North America that are cultivating Wasabia japonica which is true wasabi. Only the Pacific Northwest and certain parts of the Blue Ridge Mountains in the Appalachian Mountain range offer the right conditions for wasabi to grow naturally.
source - http://imgur.com/a/5aJjU
There is a line of products called Real Wasabi and the products use the actual plant which is a delicacy and is normally found only in specialty stores and high-end Japanese restaurants. The Real Wasabi product line includes wasabi rhizomes, or stems, which are very hard to come by and are highly valued by chefs and has several health benefits. The product line also includes wasabi powder, sauces, and salad dressings. On the Real Wasabi website they have a number of suggestions for how to use wasabi in cooking different types of foods and of course you can purchase any of the products they offer and have them shipped right to your door.