Oregon public health officials this week drafted new rules for how many plants medical marijuana cardholders may grow at home or at a grow site registered with the state.

The regulations are the result of legislation passed this year to tackle the flow of medical marijuana into the black market.

The bottom line for medical marijuana patients: A residence, no matter how many people live there, may have no more than a dozen mature plants — and that includes recreational ones.

Here’s how the new guidelines break down for patients and grow sites:

Patients growing for themselves at their residence:

• Patients and their caregivers may possess a total of six mature plants and a dozen immature plants. Those limits include any plants they opt to grow under the state’s recreational marijuana law. Under state law, households may grow up to four plants for recreational purposes.
• The law does not define the size of immature plants in this scenario.
• A residence may have no more than a dozen mature plants and two dozen immature plants. That limit includes recreational plants.