Next week will mark two years since Massachusetts voters overwhelmingly said yes on a ballot question legalizing the use of medical marijuana. When it first passed, would-be dispensary owners and entrepreneurs were seeing green. But now, they’re seeing red — frustrated by what they call foot-dragging by the state Department of Public Health in approving licenses for medical marijuana dispensaries.

Like any class, there comes a time when a student has a question or two for the teacher.

"In the supplies section that you were talking about, how much room is there for the microbial herb?" a student asks.

"Huge room for it," the teacher responds. "Basically, beneficial microbes are pretty much fungals and bacteria."

As you can tell this is not your typical class. The nearly dozen students here on this Wednesday evening are enrolled in the Northeastern Institute of Cannabis. The school, tucked along an industrial strip in Natick, opened just last month. It hopes to train people looking for careers in Massachusetts’ new medical-marijuana industry. But there’s a hitch: Two years after voters legalized medical marijuana, the first dispensary has yet to open.

"Several other states have put the programs in that can serve as models," said Mickey Martin, the Northeastern Institute’s founder and a longtime marijuana activist. "A lot of other states have done this well and they’ve put them in place without the issues we’ve seen here in Massachusetts."

Martin says around 50 people have signed up for classes — but adds the state’s delays are discouraging others.

"There are people that definitely are hesitant about putting forth $1,500 for a program to train themselves when they’re not sure if this is ever gonna happen and they’re skeptical the state will ever get their act together," he said.

The 2012 ballot question approving medical marijuana called on the state to license up to 35 dispensaries. But so far only 11 applicants have made it to the final round before approval. Martin argues that so few dispensaries will present operational challenges.

"It’s going to put a strain on those companies and those organizations because they have limited space to grow plants," he said. "There’s only so much medicine that they can produce based on the business model that they put forward."

But the Department of Public Health says it’s had to dismiss many applicants over issues ranging from inaccurate financial information to fabricated credentials. Critics argue there are no clear standards in the licensing process, but Quincy state Sen. John Keenan, who co-chairs the Senate’s Public Health Commission, believes DPH was presented with a law that provided little guidance.

"They’re starting from a faulty law and responsible for the oversight of what looks to be a pretty significant industry, and so they just want to make sure they get it right," he said.

Keenan says the rush to get medical marijuana on the market misses a key point.

"If this was a drug that was in the process of going to market, it would be in the very, very early stages and yet there’s this urgency to get marijuana on the market as soon as possible," he said.

But according to Mickey Martin, the state is just dragging its feet.

"Months go by and another month goes by and another month goes by, and they said they were going to have applications for the other counties that aren’t covered in October; and now they pushed that back to November," he said. "So at some point, where is the harm in not putting a dispensary in place because you don’t think the application is properly vetted?"

DPH says it hopes the first dispensaries will open this winter, once the 11 applicants pass the final round — and that there are at least another five applicants waiting for approval after that.

Medical Marijuana of Massachusetts president Jonathan Herlihy and attorney James Smith, who served as legal counsel to Good Chemistry of Massachusetts, discussed why medical marijuana has been in a bust in the state so far:

Watch an entrepreneur talk about the arduous process of applying for a dispensary license in Massachusetts: