The oriental mustard plant originally started growing in the foothills of the Himalayas, but migrated to the USA, UK, Denmark, and Canada.
Mild white mustard grows wild in North Africa, the Middle East, and
Europe and has also spread. Black mustard is grown in Argentina,
China, the US, and Canada.
Canada and Nepal are the world's major producers of mustard seed,
between them accounting for about 57% of world production in 2010.
The United Sates receives 43% of Canada's total output of mustard