there is no limit set in stone but the recommended ceiling is 6 veg 6 bloom some say 12 veg 6 bloom i would stick with 12 total. some counties allow more. if you are living with another med card carrier then you can have 24 total and so on. you can also be a designated caregiver for other patients which means you can grow 12 for each patient you are a caregiver for but you have to have there doctors papers posted with your grow im not entirely certain how that aspect works.