Legal Question in Real Estate Law in California

Consult with a local landlord tenant attorney, who can local at your rental agreement and give you specific advice.

Hopefully your rental agreement has a "no illegal activities" clause. If so, you can give a 3-day lease compliance or quit notice (like a 3-day rent notice but for other violations of the lease) based on the fact that growing the marijuana is a federal crime, regardless of state law. You can then evict if they have not removed all the offending vegetation within three days.