Patients can have any amount of cannabis consistent with their personal medical needs. Patients and caregivers with a state-issued ID card are immune from arrest and allowed to possess the amounts authorized by their local government. Patients and caregivers without a state-issued ID card are subject to case-by-case scrutiny. Patients keep their right to defend gardens and dosages of any amount in court. However staying within local guidelines significantly reduces the likelihood that a patient or caregiver will face legal problems.
To be as safe as possible from arrest and prosecution, patients and caregivers should stay below the medical marijuana immunity law passed by the California legislature, HS 11362.77, which sets a minimum statewide guideline of 6 mature plants OR 12 immature plants AND up to 8 ounces of processed cannabis flowers.
Federal law does not recognize medical marijuana and the Raich decision affirmed their power to prosecute cases that are legal under state law. Federal law does not “trump” state law, it is a separate jurisdiction.
A breakdown of CA county and local medical marijuana guidelines is available here.