Home cannabis cultivation in the United States and differences by state-level policy, 2019-2020.

As of 2022, all but two U.S. states with adult-use cannabis laws also allow home cultivation. Home cultivation has the potential to support or oppose public health measures, and research in U.S. states is nascent. 1) estimate the percentage of respondents who reported growing cannabis plants; 2) estimate the average number of plants grown; 3) examine the association between home cultivation, jurisdiction, and individual-level factors; and 4) examine the association between home cultivation and state-level policies in adult-use states. Repeat cross-sectional survey data come from U.S. respondents aged 21-65 in 2019 and 2020. Respondents were recruited through online commercial panels. Home cultivation rates were estimated among all U.S. respondents (n = 51,503; 46-52% male). Additional analyses were conducted on a sub-sample of respondents in states that allowed adult-use home cultivation (n = 29,100; 50% male). A total of 6.8% and 7.3% of U.S. respondents reported home cultivation in 2019 and 2020, respectively. Respondents in states that allowed adult-use home cultivation had higher odds of reporting home cultivation than respondents in states without medical or adult-use cannabis laws (AOR = 1.48, 95% 1.26, 1.75). Among respondents in states that allowed adult-use home cultivation, the median number of plants that respondents reported growing was below state cultivation limits. Home cultivation rates in the U.S. were higher in states that allowed adult-use home cultivation; however, other evidence suggests these same states had higher rates predating adult-use legalization. Further work is needed to examine how home cultivation relates to public health measures in adult-use states.