Great Big Story uncovered why you only get green-dyed horseradish at your local sushi place.
Apparently, real Wasabi takes 1.5 years to grow, is very difficult to keep happy as a plant, and costs $80 a POUND when cultivated. So dying horseradish green is easier and cheaper for most places to pass on to their customers.
Real Wasabi is pretty neat stuff...
...and can help you win at trivia:
...So at $80 a pound, I think I can forgive my local restaurant for their horseradish "problem," don't you think?