PROVIDENCE, R.I. — Trying to beat Massachusetts to the punch, marijuana-legalization advocates on Wednesday unveiled a proposal that would allow recreational pot shops to open in Rhode Island before any will be allowed to conduct sales in the Bay State.

While the opening of Massachusetts pot shops has been delayed by lawmakers until July 2018, forthcoming legislation would allow existing Rhode Island medical dispensaries to begin recreational sales six months after a bill passes. Such a bill would give Rhode Island a head start on sales if action is taken any time during the six-month legislative session.

Meanwhile in an early effort to assuage concerns from law enforcement, advocates will propose limiting home grows to just one mature plant. Anyone 21 or older who grows a plant at home would need to buy a tracking tag from the state — a system that went into effect this month for medical marijuana plants as regulators try to curb sales to the black market.

The details of this year's push led by the pro-legalization group Regulate Rhode Island were unveiled during a press briefing. A bill is not expected to be filed until next week at the earliest.

"Many of the issues that have been raised by the governor and other stakeholders are included in this bill, and that's why I think we finally have something," said Sen. Joshua Miller, D-Providence, who plans to sponsor the Senate version.

Key among those issues are regulations for edible marijuana products, such as the marijuana-infused brownies and candies that Gov. Gina Raimondo has named among her top concerns.

For the first time, advocates are proposing a law that would not initially legalize edible forms of marijuana, instead giving state agencies additional time to develop a regulatory structure, Miller said. Meanwhile all edibles would have to be reviewed by a new state Office of Cannabis Coordination before they could be approved for sale.

The group will propose taxing marijuana at 30 percent (inclusive of state sales tax) — in line with recreational marijuana tax structures seen in the western part of the country. Massachusetts' tax rate on recreational sales is far lower at roughly 10 percent, but Regulate Rhode Island Director Jared Moffat said he believes Massachusetts lawmakers will likely push for an increase before recreational stores open.

"Any lawmaker who wants to delay passage of this important legislation should be prepared to explain to the voters why they do not want to improve the economy and raise revenues," said Rep. Scott Slater, D-Providence, who plans to introduce the bill in the House.

The apparent attempts to compromise did not appease all opponents. Michael Cerullo, an Exeter psychotherapist who founded a group that cautions against rushing into legalization, said the lucrative marijuana industry has driven legalization proposals across the country potentially at the expense of good prevention and treatment practices.

"We believe 'big marijuana' has a dominant role regarding the legislation that is being introduced today while ordinary citizens to whom elected officials should be accountable are being left out of the process," Cerullo said.

Rhode Island, like many other states, has struggled to keep up with the ever-evolving industry and entrepreneurs who are hoping to make a living in a someday-recreational state. This year, the state will require that any of the more than 16,360 medical marijuana patients who grow for themselves, as well as nearly 3,000 caregivers, buy tags from the state ($25 each) to continue to grow legally.

The state Department of Business Regulation has begun processing tag purchases on its website, but patients and caregivers have until April 1 to buy their tags that must be renewed annually under law. It marks the first time since the medical marijuana program was created more than 10 years ago that the state will know exactly how many patients are growing and how many medical marijuana plants are being grown in the state legally.

JoAnne Leppanen, executive director of the Rhode Island Patient Advocacy Coalition, said some patients feel buying the tags gives them an assurance of legitimacy, but others are concerned about privacy and cost.

"It's particularly maddening for some patients because they see what's going on in Massachusetts where you can grow six plants for fun without any questions, but here as a patient you have to pay to register with the state," she said.