In the US “Hemp grows” (farm-land used to grow Hemp crops) are regulated state-by-state. Some states have a wide-open policy allowing a simple registration to grow Hemp while others have authorized very limited pilot programs with limited sites. To learn more about the regulations tied to Hemp crops on a state-by-state basis, check out the State Industrial Hemp Statutes found at the National Conference of State Legislatures.
Outside of the US, there are many countries that have full production grows and other countries have begun exploring the future possibilities of opening up their farm-lands to Hemp crops. To dive in deeper to where Hemp is grown around the world, check out the Countries Where Hemp is Grown at the National Hemp Association website.