“[T]here is considerable experience with allowing users to grow their own marijuana, and overall the effects of doing so seem not to be very dramatic.”
— “Considering Marijuana Legalization: Insights for Vermont and Other Jurisdictions,” Rand Corporation
It’s only consistent.
Cannabis is far safer than alcohol. Cannabis is less toxic than alcohol, less addictive, less harmful to the body, and less likely to contribute to violent or reckless behavior. Given that home brewing is allowed in all 50 states, it’s only consistent that adults also be allowed to cultivate limited amounts of cannabis at home.
Secure home cultivation isn’t causing problems.
Nine of the 11 states that have legalized adult-use cannabis and about half of the medical cannabis states allow personal cultivation. In the states that have reasonable safeguards — such as limiting the number of plants per household and requiring plants to be secure and out of the public view — home cultivation of cannabis simply hasn’t been a problem. No state has repealed home cultivation, and there has never been a serious push to do so.
Home cultivation is important for patients.
About six percent of all Americans use cannabis for medical purposes, according to Pew Research, but insurance does not cover cannabis. For many people with serious medical conditions, medical expenses and a reduced ability to work combine to make the price of store-bought cannabis out of reach. Securely cultivating cannabis at home is the only way for some people who can benefit from cannabis to access it. Meanwhile, allowing home cultivation only for state-registered patients is not sufficient, because most people who use cannabis medicinally do not register as patients. Those who have the lowest incomes have the most barriers to participating in medical cannabis programs.
Secure home cultivation doesn’t have a serious impact on states’ tax receipts.
Limited home cultivation, like the home brewing of beer and home gardening, is a hobby rather than a serious competitor for regulated sales. Colorado’s adult-use cannabis stores sold more than $1.55 billion in cannabis in 2018, and the state brought in more than $266 million in cannabis taxes and fees the same year.
Home cultivation helps displace the illicit market.
Most adult-use states allow localities to ban marijuana stores. In rural areas with bans, home cultivation may be the only source of cannabis other than illicit dealers.
 In Alaska, California, Colorado, Maine, Massachusetts, Michigan, Oregon, and Vermont, adults 21 and older may cultivate cannabis. In Nevada, adults may grow cannabis if they live 25 miles or more from the nearest cannabis store. Of the adult-use states, only Washington and Illinois do not allow any adult-use home cultivation; there, only patients may cultivate.
 In 2013, Pew found 12 percent of Americans used marijuana in the past year, and 53 percent of them did so at least partly for medical purposes. See www.pewresearch.org/fact-tank/2013/04/17/marijuana-use-increased-over-the-last-decade/.
 While 6 percent of Americans use cannabis medically, typically only 0.5 percent to 2 percent of a state’s population are registered medical cannabis patients. See www.mpp.org/issues/medical-marijuana/state-by-state-medical-marijuana-laws/medical-marijuana-patient-numbers/.
 “Colorado legal pot industry sales grew 3 percent in 2018, top $6 billion since recreational use began,” CNBC, February 12, 2019.