Saffron was extensively grown in the UK between the 14th and 19th centuries. In the county of Essex, it was such an important crop that the town of Chipping Walden changed its name to Saffron Walden in the mid 1600s. Nowadays, it’s used as part of our magpie cuisine, rather than anything traditionally British (as far as I know). It’s still grown on an albeit very small scale - https://www.theguardian.com/lifeandstyle/2013/nov/16/meet-the-saffron-producer-uk
