Yes. Massachusetts law permits residents 21 years or older to cultivate up to six cannabis plants on their property. If multiple adults are living on the same property, this number increases to twelve plants. However, these plants can only be cultivated in an area under lock and key. And these plants cannot be visible from the vantage point of a public place. While it's legal for residents to grow their own plants, they are not permitted to manufacture their own extracts or concentrates using any liquid or gas. Medical marijuana patients are also allowed to cultivate their cannabis, and are allowed to grow additional plants to maintain their 60-day supply if they apply and are approved for a Hardship Cultivation Registration. See www.masscannabiscontrol.com/hardship-cultivation-registration/