Van Dang was jailed for four years.
Their arrests came on the back of police officers executing search warrants on houses and nail bars in Blackburn, Darwen and Bolton.
Van Dang, 49, of Harwood Street, Darwen; Ho Qa Dong, 25, of Sunnymere Drive, Darwen; and Cam Thi Ho, 30, of Sunnymere Drive, Darwen; all pleaded guilty to conspiracy to produce cannabis when they appeared at Preston Crown Court. They were sent to prison for four-and-a-half years, 27 months and three years respectively. Thi Ho, 35, of Harwood Street, Darwen also pleaded guilty and was given a 10 months jail term, suspended for 12 months, with a three-month curfew.