Some retired couples move to Florida; the Larsons decided to farm worms

BROOTEN, Minn. -- Mike and Karen Larson have a nursery on their property -- one that contains thousands of baby worms.

"If you would have told me I would have been a worm farmer five years ago, I would have laughed at you. I thought, no way. I didn't know anything about it," Mike Larson said.

Now, he probably knows more than he ever wanted to.

When the Larsons retired a few years ago, they moved from the Twin Cities to central Minnesota. Mike got a little bored so he decided to become a farmer.

His worms aren't the type of worms you use to catch walleyes. They are nightcrawlers from Africa.

The Larsons sell the worm castings, what the slimy invertebrates leave behind.

When the castings are put in the soil, plants eat it up.

"It's the fecal matter of the worm," Mike said. "It's like a pro-biotic for your soil. We thought we could help people if we could help them eat better."

There are more than 6,000 African nightcrawlers in each of the Larons' bins, and there are about 250 bins in the building.

If you're doing the math at home, that's more than a million wiggling worms in one room.

The process works like this: During the winter when the ground is hard, Mike and Karen harvest peat from a peat bog near Brooten. It's like bedding for the worms.

"We have to have the right amount of moisture, the right amount of feed. If all of that is right, everything else kind of falls into place," Mike said.

The nightcrawlers wouldn't survive Minnesota's colder climate, so the temperature in the worm room is between 70 and 85 degrees.

"I always call it my paradise. My tropical paradise in the winter. We'd come in here it would be 74 degrees with 80% humidity,"  Karen said.

Several times a week, harvesting takes place. Bins full of nightcrawlers are run through a machine called a trommel.

It separates the castings from the cocoons and the worms. The nightcrawlers go for a bit of a ride, like the world's smallest cliff divers and back into the bins.

"It's like a Valleyfair ride for worms. We hope they are liking the ride," Mike said.

In addition to organic worm castings, the couple also sells something called worm tea. You wouldn't want to drink it, but the plants love it.

"This is what the worm tea looks like when it's done. I always say I want it to look like a fine IPA,"  Mike said.

The Larsons named their farm Brut Worm Farms in honor of the Brut snowmobile company that used to be in Brooten. The couple offers tours of their facility.