The union, in its filing to the state Department of Labor Relations, said the writeups were issued as part of an illegal anti-union campaign by Mayflower managers that also included interrogating employees and directing some to stop engaging in legally protected organizing activity.

In a formal complaint to state regulators Thursday, the Local 1445 branch of the United Food and Commercial Workers Union, or UFCW, said managers at iAnthus subsidiary Mayflower Medicinals issued written warnings to two workers involved in unionization efforts for minor alleged infractions that “do not normally lead to discipline.”

A labor union trying to organize workers in the Massachusetts marijuana industry has accused national cannabis conglomerate iAnthus Capital Holdings of violating state law by retaliating against pro-union workers at its Holliston cultivation and processing facility.


In a brief statement, a spokeswoman for iAnthus said Mayflower employees "will have the opportunity to decide whether they want union representation.”

“Mayflower fully supports its employees and respects their rights to make informed decisions about their employment, including the right to collectively bargain,” she added.

Any sanctions for the alleged labor law violations are likely to be mild, union officials conceded, since neither worker was fired or demoted. One possible remedy if regulators find Mayflower was at fault: The state could order the company to post signs reminding workers of their right to organize.

Mayflower employs about 45 workers at its Holliston cultivation facility, which recently won a state license to expand from medical marijuana into the recreational sector. The company also operates a medical marijuana dispensary in Boston’s Allston neighborhood and expects to open a recreational pot shop in Worcester this year.

Union officials said 17 of Mayflower’s Holliston employees work in strictly agricultural roles that are exempt from many federal labor laws, but protected under stronger state laws. They’re asking the Massachusetts Department of Labor Relations — which mostly deals with public sector unions but also provides some oversight for agricultural workers who cannot seek federally overseen union elections — to order Mayflower to the bargaining table with those workers and their union representatives, after a third-party arbitrator verifies that a majority of the 17 have signed union cards. (Organizers said 13 have so far.)


Organizers said a slim majority of the remaining 28 employees, such as those who process the harvested marijuana flowers into edibles and oils, have also signed cards. But they are reluctant to proceed to a formal union election overseen by the National Labor Relations Board, as Mayflower wants. That’s because marijuana remains illegal at the federal level, and a ruling by the federal board that workers at state-licensed cannabis facilities are ineligible for labor protections could unravel unionization efforts in the industry across the country. (An election would also give the company an extended period to lobby its workers to vote against organizing, including at required meetings.)

Instead, the UFCW hopes a public campaign will pressure Mayflower into signing a so-called labor peace agreement and voluntarily recognizing the union if a majority of workers want to form one.

The union noted that iAnthus has signed similar labor peace deals — under which the sides stop disparaging one another and union representatives are granted access to the worksite in exchange for dropping any stoppages, pickets, or boycotts — with workers at its medical marijuana facilities in New York and New Jersey, where regulations require licensed cannabis firms to do so.


“We’re not sure why they’re treating Massachusetts differently,” union spokesman Jim Carvalho said in an interview. “Nobody really wins from fighting. We think the best way to make sure this industry is successful and creates good jobs is not go through the typical anti-union election process and just recognize that a majority wants this.”

The UFCW has said it represents more than 10,000 marijuana workers in 15 states. It recently expanded into the Massachusetts cannabis industry, successfully organizing about 115 workers of Sira Naturals under a labor peace agreement in November.

Workers at Mayflower’s facility said they were inspired by the news that Sira’s workers had unionized, and hope collective bargaining will bring higher pay, better benefits, and fairer disciplinary policies.

Dave Schermerhorn, a 33-year-old grower for Mayflower who makes $17 an hour, said pay at the firm was low and stagnant considering the often physically grueling work and ever-rising production quotas. That complaint was echoed by other workers who declined to be named, fearing retaliation.

“We do so much for this company and the best they can do for us is throw a pizza party once in a while — that ain’t no perk,” Schermerhorn said. “They don’t care about our rights, and there have been a lot of injustices. At the end of the day, you’ve got a lot of people here who are dedicated and often drive here from far away, and they’re not getting much for it.”


Dan Adams can be reached at daniel.adams@globe.com. Follow him on Twitter @Dan_Adams86.