The proposed rollback of home grow limits in Maine has some marijuana advocates crying foul.

Limiting the number of flowering plants grown at home for recreational use at three is half what Maine voters approved in November 2016, but it puts Maine squarely in the middle of the pack among those states that have legalized adult-use cannabis.

“We don’t want Maine to be out in front of other states on marijuana,” said Sen. Roger Katz, R-Augusta, the Senate chairman of the marijuana committee that overhauled the voter-approved law. “Colorado had problems with home grow and cut theirs, so we did, too.”

Like Maine, Colorado, Alaska and Washington, D.C., limit home growers to three mature plants. California and Massachusetts allow up to six, and Oregon caps it at four. Vermont will allow just two when it goes legal in July. Washington state forbids home grow altogether.

Nevada home-grow rules vary depending on where one lives. A home grower can have up to six plants at home for personal recreational use, but only if the person lives at least 25 miles away from one of its state-licensed retail marijuana shops.

If the Maine bill becomes law, it will roll back the only part of the Marijuana Legalization Act that went into effect after the vote. Lawmakers delayed the issuance of retail licenses, but residents have been able to grow up to six plants since Jan. 1, 2017.

If lawmakers override the promised gubernatorial veto, the law would give residents six months from implementation to shrink their grow from six flowering plants to three. In addition, they can possess 12 immature plants and an unlimited number of seedlings.

Bill supporters like Katz say that the three-plants rule offers Mainers the personal freedom to grow their own, but limits the risk of personal grow overages fueling black market sales. Colorado’s former marijuana czar, Andrew Freedman, warned Maine lawmakers about this risk last year.

Like Maine, some states limit the number of recreational plants allowed in a household, or on a piece of property, to avoid big grows that can lead to black market sales. In some states, towns impose tougher limits – for example, some California towns ban outdoor grows.

How much marijuana can growers get from a plant? It varies from grower to grower, depending on skill, where and what they grow and the equipment. A first-time grower with a 200-watt lamp might get 1½ ounces per plant, while a veteran outdoor grower can get a pound.

That may sound like a lot, but advocates note that it’s not what voters approved at referendum. And since legalization, while people have been allowed to grow six flowering plants, Maine law enforcement has not complained about runaway home grows, they say.

“Self-reliance and sustainability are part of what Maine’s about,” said David Boyer, director of the state chapter of the Marijuana Policy Project. “I don’t see the issue with Mainers growing for themselves. We should not go back and recriminalize something we just made legal.”

Some recent high-profile marijuana arrests in Maine have been the result of diversion from the state’s medical cannabis program, not adult-use home growers, Boyer said. He worries a three-plant home grow limit might actually drive people to the black market, he said.

Boyer’s group has taken no position on the recreational bill, deeming it flawed but long overdue.

The reduction of home grow limits is one reason why Legalize Maine, the advocacy group that wrote the ballot-box law, opposes the pending adult-use bill. The group’s president, Paul McCarrier, called it a “slap in the face to Joe Six-Plant, and Joe is voting in November.”

The adult-use plant limit might help Maine’s medical marijuana community, however. The adult-use bill does not reduce medical home grows, which will stay at six mature plants, giving those who use the plant as medicine another reason to renew their medical card.