Home cultivation across Canadian provinces after cannabis legalization

AIMS: Little research exists on home cultivation in Canada after non-medical cannabis legalization in 2018. The aims of the study were to: (1) estimate the percentage of home cultivation before and after legalization; (2) estimate the quantity and expenditure of cannabis plants; and (3) examine the association between provincial policies and home cultivation after legalization. METHODS: Repeat cross-sectional survey data come from Canadian respondents in the International Cannabis Policy Study in 2018, 2019, and 2020. Respondents aged 16–65 were recruited through online commercial panels. Home cultivation rates were estimated among all respondents in 2019 and 2020 (n = 26,304) and among a sub-sample of past 12-month cannabis consumers in 2018–2020 (n = 12,493). Weighted multivariable logistic regression models examined the association between home cultivation and provincial policies among all respondents, 2019–2020. RESULTS: Cannabis consumers in 2019 (7.9%; AOR = 1.47, 95% CI: 1.07,2.01) and 2020 (8.8%; AOR = 1.62, 95 %CI: 1.18,2.23) had higher odds of reporting home cultivation in the past 12 months than pre-legalization (5.8%). Post-legalization, past 12-month home cultivation was lower in Quebec and Manitoba, the two provinces that prohibited home cultivation (3.2%), than in provinces where home cultivation was permitted (6.8%; AOR = 0.48, 95 %CI: 0.39, 0.59). The median number of plants grown across all provinces was between 3.1 and 3.5 in all years. CONCLUSIONS: Almost one in ten Canadian cannabis consumers reported home cultivation of cannabis in 2020, with modest increases following legalization and most growing within the non-medical limit of four plants. Home cultivation was less common in provinces where home cultivation was prohibited.