The actor, Blues Brother and TV veteran (ABC’s “According to Jim”) stars in “Growing Belushi,” a three-part Discovery series taking viewers inside the legal cannabis business he runs from his southern Oregon spread, Belushi’s Farm. It premieres Wednesday at 10 p.m.

“Once you engage with this plant, it kind of leads you where you want to go,” says Belushi, 66, who brought the now-93 acre farm on the Rogue River just as marijuana was being legalized in Oregon. “I was like, ‘Wow, new agriculture, let’s do that,’” he says. “And it started me on that path.

“It’s taken me to a whole different level.”

Belushi says he’s “a boots-on-the-ground guy” and regularly visits marijuana dispensaries. His business philosophy changed, he says, when he encountered an Iraq War vet on one of those visits.

“He said, ‘I was a medic and I saw things that happened to the human body that nobody should ever see.’ He had PTSD and had gotten off Oxycontin with cannabis and said, ‘I couldn’t talk to my kids or my wife and I couldn’t sleep, but your Black Diamond OG [cannabis] allows me to do that.’ He teared up and hugged me.

“This is a business about healing,” he says. “People are suffering from depression, PTSD, Alzheimer’s, anxiety. I always followed my passion and the money came and the business behind it — but this vet changed my purpose.”

And, if you’re wondering, Belushi doesn’t sample his product too much.

“I’m a microdoser. If I have a joint it lasts me like 10 days,” he says. “I take 2.5 milligrams of [THC-infused] Bhang Chocolate — it’s an easy sleep and I wake up feeling great — and maybe a little hit of [hybrid cannabis] Cherry Pie — which makes me pleasant and charming and chills my anxiety and I get along with my wife.

“I call it ‘The Marriage Counselor.’”

Most of “Growing Belushi” shows him running the business he started in 2015 and interacting with his staffers, including his prone-to-exaggeration cousin, Chris — who oversees the day-to-day operations — and young growers Ben and Alex, whom he’s known since they were kids (he’s friends with their father). Viewers also get a glimpse at his personal life.

Another featured character is Jack Murtha, aka marijuana celebrity “Captain Jack,” whose rare strain of Afghan weed was known as “The Smell of ‘SNL’” when Belushi’s late brother, John, rose to stardom on “Saturday Night Live” in the mid-’70s.

“I met Jack when Danny [Aykroyd] and I started doing the Blues Brothers and we were playing an East Coast gig,” Belushi says. “Jack and Danny were friends, and when I started my business, Danny said, ‘You can have Captain Jack’s strain. It’s very unique.’ Where else would those guys [on ‘SNL’] stay up and get stimulated and come up with ‘The Coneheads?’”

Belushi mentions his brother several times — John’s wife, Judy, appears in the series, along with Aykroyd — and says he thinks Belushi’s drug use, and eventual overdose death in 1982, was partly caused by a traumatic brain injury he suffered while playing high school football.

“I saw my brother have a seizure in my house and we didn’t know what that was from,” he says. “It was from banging his head and getting his bell rung. That’s what I believe. If Johnny was a pothead, he’d be alive today.

“In the second episode I go to Colombia and I go up in a helicopter and ride into the ‘Red Zone,’ which is where all the coke is grown,” he says. “I look down on those fields and there’s a moment that really struck me. I went, ‘Wow, these fields are really cemeteries, all those people who died from that coke.’ I wondered, looking at these fields, if I’m looking at the coke my brother used.

“If Colombia can take these fields and convert them to cannabis fields, they can heal people instead of killing them.

“Everybody is screaming inside,” he says. “Sometimes we take a Xanax or Ambien or a prescription medication. [Cannabis] is the safest, most non-violent choice. It helps repair families in trauma — not only losing a sibling, like me, but illness in the family, the loss of a job or a house … I’ve experienced it myself with divorce. It’s for the battle in all of us.

“One of the reasons cannabis is so prolific is that it finds a peaceful way to stop the screaming.”