The battery-powered trains in Bud Lutz's back yard run past a miniature gravel pit, ski gondolas and even a steaming volcano. But the lush plants and moving gadgets aren't the only reason some visitors show up for the free tours he gives of his railroad garden in Eagan.

"This is my grandpa, but you can call him Santa." That's how 5-year-old Alexa Lutz-Chase introduces guests at the open houses Lutz holds one Sunday a month during the summer.

Lutz, 69, tends to wear red shirts, which set off his bushy white beard and the striped train cap he sports in a photo on his business card. In restaurants and shopping malls, young children stop and stare.

"They look at me kind of funny, and I nod and wink at them," said Lutz, who actually does play Santa Claus every winter. He worked at a mall in Brooklyn Center for seven years until last year, when he had a heart attack and spent much of the season recovering.

Now he's back in the railroad garden that he started building eight years ago with encouragement from his wife, Ayako, who has since died.

Every spring, a group of Lutz's fellow train enthusiasts in the Minnesota Garden Railway Society get together to show off the new models they built over the winter. The group has about 100 members, but perhaps only 20 with garden railroads. This year, Lutz added a meticulously crafted replica of the train depot in his small North Dakota hometown, which sits under a water tower, near a tiny popcorn vendor and just down the track from a burned building surrounded by miniscule firefighters.

Lutz has been opening his garden to strangers for years, but he began getting more visitors after local newspapers wrote about his hobby and a woman from the Eagan Convention and Visitors Bureau came over and asked if he would be willing to host bus tours. He's had thousands of guests since then, and as many as 400 in a single day. And he's even been featured on a national television show about gardening.

The bus tours are off this year because of the economy, he said, but he still shows off his garden regularly.

Occasionally, the families that call asking to bring children over aren't so much interested in trains as they are in an off-season visit with Santa. And that's just fine by Lutz. "You can never be too busy for the kids," he said.

Sarah Lemagie • 952-882-9016