PHOENIX — Medical marijuana users have no right to grow their own plants once a dispensary moves within 25 miles as the crow flies, a state hearing officer concluded Tuesday.

But some rural residents may get to start cultivating again next year.

Hearing officer Tammy Eigenheer rejected arguments by Arlin Troutt that the 25-mile rule, part of the original 2010 voter-approved Arizona Medical Marijuana Act, violates his constitutional rights because it allows others living outside that zone to continue to cultivate the drug.

Troutt, who listed his residence as Gold Canyon in Pinal County, had no better luck with his claim that the closest dispensary did not count because it did not offer “naturally-grown marijuana product that had not been exposed to pesticides and other chemicals that made him sick.” Eigenheer said there are other dispensaries available that may have the kind of product he wants.

Eigenheer also said it is irrelevant that Troutt is more than 25 “road miles” to the dispensary, saying the only thing Arizona law considers is the distance using a straight-line approach.

But state Health Director Will Humble said the argument about driving distance and convenience makes sense, so he is crafting changes to the rules so that beginning sometime next year, the distance will be calculated solely by road miles.

Troutt could not be reached for comment.

The 2010 law allows those with certain medical conditions and a doctor’s recommendation to obtain up to 2½ ounces of marijuana every two weeks. It also requires users to buy the drug from one of several dozen state-regulated dispensaries.

But anyone more than 25 miles from a dispensary can grow their own plants. And since there were no dispensaries when the law was enacted, that gave the right to all users, including, initially, Troutt.

But when Troutt sought to renew his annual state permit to use the drug earlier this year, health officials told him he could no longer grow his own plants and would have to buy from a dispensary. So he appealed.

Humble said the 25-mile rule honors the intent of voters who wanted a system that requires marijuana to be handled through regulated dispensaries, complete with reporting requirements, rather than a free-for-all where users can grow what they want and distribute it to others. He said about 98 percent of the approximately 56,000 medical marijuana users live within 25 miles of at least one dispensary.

Similarly, Humble said anyone who wants organic marijuana has lots of options, with more than 90 dispensaries in operation.