Frequently asked questions Can I grow marijuana In California with an MMJ Card? Yes, a Medical Marijuana patient or their caregiver can grow up to six mature plants, 12 immature plants or a greater amount consistent with the patient’s reasonable needs. To grow more than this, you will need to obtain what is called a 99 plant growers recommendation. A permit can be obtained through a Leafwell doctor if required, as an addendum to your doctor’s recommendation. Here are our costs for a growers recommendation: $99 for 25 plants $149 for 50 plants $199 for 99 plants