South-metro fungus fans know the mushroom man

Tom Peterson follows the rain.

He's the mushroom man, as many in Dakota County have come to know him for the mushroom-hunting seminars he teaches once a year. And within a day or two of big rains, Peterson is often in forests gathering his bounty.

He welcomed the rain last week so he could quickly gather about 200 pounds of several species to cook for his class later this week.

Peterson has had a passion for the fungi since he was a boy at his father's northern Minnesota resort, listening to an American Indian named Cliff Crow tell of the lore of the mushroom, which since people have been gathering and eating for thousands of years, just as Peterson did when he was 9.

The story that really ignited the boy's imagination was that of Foxfire, the name that the Chippewa gave mycelium -- the tiny threadlike structures that mushroom spores make. In the night, masses of the fibers glow bluish white between the wood and bark peeling away in dead trees. The Chippewa used Foxfire to mark trails and to make seek-and-find games for their kids in the forest.

The history, mythology and fear surrounding mushrooms fascinated Peterson, a native of Richfield. As he grew, so did his interest. And he came to see mushrooms as much more than fungi.

It's turned serious professionals into enthusiastic hunters joyfully laughing like children at play. And it's changed lives, he said.

Know your mushrooms

From the golden chanterelles with their fruity flavor to the coral mushrooms that taste peppery, the fungi vary widely, with about 200,000 species in the Upper Midwest. Some taste like meat, others like watermelon and still others like nuts.

"If you like store-bought mushrooms," Peterson said, "wait till you try wild mushrooms. These are flavors you've never had before."

Mushrooms are wildly popular at farmers' markets, where regulars line up before Peterson can unload them from his car on a Saturday.

He encourages people to pick mushrooms, which grow in an array of shapes, from lobster claws to yellow lanterns, and a rainbow of colors. But hunters have to know what they are picking.

Mushrooms that are safe to eat in one part of the world can resemble deadly species in another part. Two years ago, for example, a St. Paul family of Asian immigrants was hospitalized after eating poisonous mushrooms. Salena Thao, 10, died.

Peterson's seminar is designed for people who have no experience with mushrooms. In the first class, he tells about using their common and Latin names and how to spot the deadly Amanita genus.

On the second day, his students head out to the woods around Lebanon Hills Regional Park with his instructions "to pick everything." He later checks their finds and every year finds poisonous ones.

His seminar doesn't focus on the study of mycology, or of all the fungi of the world.

"This is for people who love to be afield and who love to cook," he said.

For 38 years, as he raised two sons as a single father, Peterson installed heating and ventilation systems in commercial buildings. Two years ago, he retired to pursue his dream full time. Now 57, he cultivates and clones mushrooms. He has big plans.

"One of the things I'm working on right now is a fungi that digest petroleum waste," Peterson said, adding that others are working on the same pursuit.

He had stumbled upon mushrooms' ability to break down petroleum waste such as diesel and spilled or used motor oil after he spilled oil from his chainsaw, and mushrooms sprouted. Now, he's busy seeing how far he can take that. He said the mushrooms break down cellulose fiber as they consume dead trees and plants, returning minerals to the soil.

"Because they're grand disassemblers, the hydrocarbon bonds are broken [and] the mycelium absorb the oil," he said. "Diesel waste is absorbed, broken down, and the process of peroxidation (deterioration) occurs, which is the first step toward fungal sugars. The fungal sugars are converted into food nutrients available for plants."

The fungi then convert to spores and attract insects. The insects lay larvae, which attract birds. The birds drop seeds. In his controlled areas, Peterson said, "We're able to take waste oil products and turn them it into an oasis of life."

Mushroom hunters can quickly gather sacks full on a foray, but unless they dehydrate, freeze or can them, they won't last more than a few days. So Peterson offers advice:

"If you've got 40, 50 pounds of mushrooms, don't forget your friends and family. Those are the most important people we'll ever have in our lives. Share your good bounty with them, and it'll come back to you."

Joy Powell • 952-882-9017