Marijuana plants 2015

Marijuana plants are seen growing at the MedMar Healing Center in San Jose, California, in this 2013 photo. California is among at least five states, including Massachusetts and Maine, in which legalization measures are likely to appear on ballots in November 2016.

(David Paul Morris / Bloomberg News)

By STEVE LeBLANC

BOSTON -- State Senate President Stan Rosenberg says lawmakers should consider putting a nonbinding question on the 2016 ballot asking voters if they would support legalizing the recreational use of marijuana.

The Amherst Democrat said he's trying to avoid the possibility voters might approve another, perhaps poorly written, ballot question also aimed at legalizing pot.

Two pro-pot groups have already said they hope to put questions on the 2016 ballot aimed at the full legalization of it.

Rosenberg told reporters after a Monday meeting with Gov. Charlie Baker and House Speaker Robert DeLeo that the national trend appears to be in favor of lifting prohibitions on marijuana. He said the nonbinding referendum would give lawmakers a green light to craft a legalization law through the normal legislative process.

"When you put something as complicated as this is on the ballot, and it gets passed, it comes back to the Legislature with people saying, 'Gee, there are parts of this that don't work,' and then the Legislature is forced into the position of trying to amend the people's law," Rosenberg said.

Rosenberg declined to say whether he supports legalizing recreational marijuana. Baker, a Republican, and DeLeo, a Democrat, said they oppose legalization.

Baker called Rosenberg's proposal an interesting idea.

"I'm opposed to a nonbinding referendum," Baker said. "I'm opposed to a binding one. I'm just opposed to the whole concept."

Asked if he had ever smoked marijuana, DeLeo said, "When I was in my late 20s, believe it or not. I was late to the game and only a couple of times."

Rosenberg said, "I went to college in the '60s." Baker said, "I went to college in the '70s."

One possible 2016 ballot question is being proposed by Bay State Repeal.

The group said the question would be about whether to let adults 21 or older grow and buy the drug while taking steps to ban sales to minors, including undercover sting operations at stores that sell pot. Those who provide marijuana to minors, except as recommended by a doctor, would face fines and potential jail time.

The question wouldn't require marijuana sellers be licensed by the state and wouldn't tax marijuana sales, which has been a major selling point in states that have legalized it.

A separate bill before state lawmakers would tax and regulate marijuana like alcohol and allow adults 21 years or older to possess and grow marijuana. It also would create a regulated system of licensed marijuana retail stores, cultivation facilities, processing facilities and testing facilities.

The bill is being pushed by the Marijuana Policy Project, which says it plans to put its own question on the 2016 ballot to regulate and tax marijuana if the bill fails to win support on Beacon Hill.

Massachusetts voters have been open to relaxing marijuana laws. In 2008, they approved a question decriminalizing small amounts of marijuana. In 2012, they approved a question legalizing up to 35 medical marijuana dispensaries statewide, but that effort has stalled with no dispensaries currently open.