STORY: The gang dried the marijuana plants, packaged them and sent them to parts of Spain, Switzerland, Holland, Germany and Belgium.
Police raided a series of farms and production plants across Spain in an operation called Gardens.
Nine men and 11 women, aged between 20 and 59, were arrested. None of them were named.
The gang were detained in Toledo, Ciudad Real, Valencia and Asturias last month but details of the operation were made only public on Saturday.
No details were given about when the suspects appeared in court.