ST. PAUL, Minn. — Garrison Keillor is not spending his time in retirement baking Powdermilk Biscuits or drinking coffee down at the Chatterbox Cafe now that he's hung up his microphone as host of his popular public radio show, “A Prairie Home Companion.”

He turned 75 on Monday and boarded a bus Tuesday for a 28-city “Prairie Home Love & Comedy Tour — 2017,” which he vows will be his last.

“I don't think you should go out onstage after the age of 76,” Keillor said during a recent interview at his St. Paul office. “You don't want to fall down out there and then all of these people, you know, there's a sudden intake of breath. And men in white jackets come in from the wings and put an oxygen mask on you.”

“You don't want that to happen. It's too much entertainment for the dollar,” he added. “An entertainer is supposed to go away and have a quiet dotage, and you know, lose your marbles in private and not do this out where people can see you.”

Keillor started his Saturday-evening radio variety show featuring tales of his fictional Minnesota hometown of Lake Wobegon — “where all the women are strong, all the men are good-looking, and all the children are above average” — in 1974. He went out with a final show at the Hollywood Bowl in July 2016 and turned the show over to mandolinist extraordinaire Chris Thile, who starts his second season as “Prairie Home” host on Oct. 7.

Keillor admits he misses being on the air and said he hasn't listened to “Prairie Home” since Thile took over.

“I keep my distance because I was given tremendous freedom when I did the show and it took a while for me to even get a grasp of what was involved. Made a lot of mistakes in the course of all those years. So the new people really should be given the same freedom and allowed to make their own mistakes,” he said.

“I would miss it too much, I think. I really would feel a big loss, I think, if I listened to it,” he said. “I really have to turn my back. When the bishop steps down, the bishop is supposed to leave town. You're not supposed to, you know, keep going back to the church.”

Wearing his signature red tennis shoes without socks and his gray hair freshly cut as he prepares to hit the road, Keillor talks about his projects, which include finishing a screenplay about Lake Wobegon. The plot involves a New York weatherman coming back to town for his father's funeral. It's based on a character from Keillor's 1997 novel, “Wobegon Boy.”

Keillor hopes the movie will be filmed in Minnesota. Keillor's radio show characters were the basis of director Robert Altman's last movie, “A Prairie Home Companion.”

“We just have to find a town that can be Lake Wobegon, and then I think we should be all set to go,” Keillor said. “And we have to teach people to talk, you know, we have to teach actors to talk, and not talk as they did in the movie 'Fargo,' which is not quite right.”

Keillor has survived heart surgery, a minor stroke and seizures, and recently had surgery on his left eye for cataracts and glaucoma. A former chain-smoker, he gave up cigarettes and alcohol years ago, and muses about how modern medicine has given him a second chance.

“You have all of these miracles,” he said. “It's an enormous luxury.”