The number of medical marijuana clinics in Minnesota will almost triple in the next few months.

That’s by design. In fact, it’s mandated by state law.

When Minnesota legalized medical cannabis last year, lawmakers set some of the most restrictive ground rules in the nation. Minnesota would decide who could grow the drug, who could buy it, and in what form it could be sold. The state also strictly limited where medical marijuana can be sold — just eight storefronts, scattered across the state.

At the time, critics worried that there wouldn’t be enough cannabis clinics to serve all the patients who might want access to the program.

These days, the main worry is that there won’t be enough patients to keep the lights on in all eight clinics when they finally do open.

As of last Friday, 1,159 people had enrolled in the state program. Minnesota has some of the lowest patient enrollment numbers per capita among the 23 states that have legalized medical cannabis.

There are about 0.2 medical marijuana patients for every 1,000 residents, according to the nonprofit policy site ProCon.org. The national average is eight patients per 1,000. In Michigan and Maine, there are 18 patients for every 1,000 residents. In states such as Oregon, Colorado, California and Washington, the average is 19.

Right now, the only legal way to take medical marijuana in Minnesota is to be diagnosed with a devastating illnesses — nine conditions qualify patients to enroll in Minnesota’s program, including cancer and seizure disorders. To enroll, patients need a health care provider to certify that they have a qualifying condition and they can only take cannabis in pill or liquid form.

Smoking the marijuana plant remains illegal under state law.

Although the planners calculated that as many as 5,000 qualifying patients might enroll in the program in its early years, it has reached barely a fifth of that tally, and the three clinics now operating in Minneapolis, Rochester and Eagan have been able to easily handle the patient load.

The nine-month-old program has struggled with sluggish enrollment, price hikes and doctors and clinics that have been reluctant to certify patients to sign up for it.

In August, the program will expand to serve patients diagnosed with intractable pain who haven’t responded to traditional drugs or therapies. It’s a move that could bring in tens of thousands of new patients.

But under state law, Minnesota’s two cannabis corporations — LeafLine Labs and Minnesota Medical Solutions — must open five more clinics before Aug. 1, whether customers are ready to buy or not.

Both companies have predicted that the addition of pain patients should provide a steady stream of customers, which in turn could help drive down prices.

MinnMed opened the doors of the state’s first clinic in downtown Minneapolis at midnight on July 1. Soon after, it opened a second care center in Rochester.

Earlier this month, the company led local press on a tour of its planned facility in Moorhead, which will open at 104 7th St. S., in a former Subway sandwich shop. The company’s fourth clinic will open somewhere in the western suburbs, although the location has not yet been set. Both are expected to open in May or June.

Minnesota’s second cannabis clinic opened a few hours after the first, in a suburban medical complex in Eagan. On its website, LeafLine Labs pledges that storefronts in St. Cloud, St. Paul and Hibbing are “coming soon.”