Jeff Johnston worries he'll have to go outside the law for his medicine when new medical marijuana growing rules take effect this year.

It'll be seven years in October since the 49-year-old Petrolia man suffered 11 epileptic seizures and doctors discovered a slow-growing tumour in his brain.

After chemotherapy about five years ago, Johnston received his licences to possess and grow medical marijuana.

Since then, he's smoked his prescribed 4.5 grams per day and grown 25 plants — enough for a year's supply, he said — in a greenhouse in his backyard.

But new rules introduced by Health Canada in 2013 will prohibit him and anyone else from growing marijuana for themselves as of April 1.

Instead, the federal government is replacing its own distribution system, personal-use and designated-person growing licences, with licenced producers.

It costs Johnston $1.10-1.50 a day to grow his marijuana, which is manageable, he said, with the $1,700 he lives off of a month through the Ontario Disability Support Program and odd jobs. He also has two 13-year-old daughters and one, 18, in university.

The threat of costs skyrocketing as he's forced to go through licensed distributors has him worried.

“You consider the mailing, all the shipping and everything else,” he said, noting customers have little recourse if producers decide to raise prices.

“I have to grow my medicine,” he said. “Because if I don't I'm going to have to become a criminal … as silly as that sounds.

“But what do I do?”

Health Canada has received more than 380 applications for licences, a government official recently said, but only three have been approved and posted on the federal agency's website so far.

System changes were brought on after an RCMP report last year that said criminal groups are using the medical marijuana system to obtain and distribute the drug.

Health Canada didn't immediately respond to emailed questions about Johnston's concerns.

At an October checkup with his doctor, Johnston was told his tumour hasn't grown discernibly in four and a half years.

“That's right about the same time I started smoking,” he said.

He had smoked marijuana before his diagnosis, he said, but nowhere close to his prescription amount. He also takes Dilantin for epilepsy.

He's concerned the new system will make him an easy target, he said, since the government has his personal details through the current medical marijuana access program.

“You can be assured that when the federal government changes its law, my friends down at the Petrolia OPP station will be here April 2 to make sure,” he said.

Meanwhile, the changes won't curtail illegal grow ops, he said.

“The only people that are going to be forced to stop are going to be the legal people like me,” he said, noting he uses some of his dried stock to make butter and baked goods — as do many other medical marijuana users.

The government “should leave it well enough alone and look seriously into it,” he said. “Not just the quick and instant tax grab.”

tyler.kula@sunmedia.ca