They obtained a warrant a short time later to search the warehouse, discovering hundreds of plants and seven people hiding inside, police said.
Lorenz said the seven men and women arrested appeared to be workers. Their names were not immediately available.
The warehouse rests on the corner of San Fernando Road and Tyburn Street, just outside the Glendale border.
Some neighbors of the warehouse on Thursday said their complaints about the warehouse were never investigated by Los Angeles police, despite its proximity to the station on San Fernando Road.
Neighbor Rick Corsini, who's architecture firm is next door to the growing operation, said he has been concerned with activity inside the warehouse for about a year.