(A version of this story first appeared at Hemp Industry Daily.)
MMJ growers oppose the measure.
The bill would require marijuana to be grown indoors in greenhouses or hoop houses.
The bill’s sponsor, Sen. Tom Jacobson, said that most marijuana growers already grow indoors to maximize year-round production, while outdoor Montana farmers could use hemp to diversify their operations.
Montana’s agriculture department also supports the bill.
But medical marijuana growers objected, saying the bill would impact the investments they have already made in outdoor facilities.
The proposal would not grandfather marijuana cultivators already licensed to grow outside.
Rules for adult-use marijuana production in Montana are still in development.
The Montana debate comes as outdoor marijuana and hemp farmers are increasingly coming to loggerheads over pollen drift, setting the stage for growing disputes in areas with thriving outdoor cannabis production.
According to researchers at Michigan State University, a single male cannabis flower can produce 350,000 pollen grains capable of traveling great distances in the wind.