That Christmas tree business, you think: There's a sweet racket. Plant a seed, drop by 10 years later, chop it down and rake in the profits. Mother Earth does all the work.

You're wrong. There are ninjas involved.

We caught up with Trent Johnson, owner of B&J Trees, and asked how the business works. He'd know.

"I grew up with trees. My dad was a tree grower. When I was 18 and he was selling his farm, he asked if I had any interest in the business," he said. "But I had to do my own thing."

Over college break, though, he'd go back. "I'd shear the trees with machetes for the new owner and shear in the summer. It's a demanding job, with the sap and the bees and the bugs, so I hired some guys, and we sheared at tree farms all over the Midwest. Now we shear a million trees a year at over 80 farms."

Wait a minute. Shearing? Machetes?

Yes, the trees don't just grow unattended. It takes teams of men with long knives striding through the forests, whipping away like arboreal dervishes, shaping the pines and firs.

"You have to interpret the growth of the tree," Trent said. "See what it's trying to accomplish, imagine what people like as a tree."

It's fast work: "You're swinging a 3-foot knife with both arms, with precision aim that hits the branch within a quarter inch. Thirty seconds a tree -- our arms are just moving up and down. You got a testosterone- fueled guy, he can shear 120 to 140 trees in an hour. They're tree ninjas."

But let's say 10 years of blade work still can't save an ugly tree. What then?

"For us, our farm [a 200-acre spread in Clear Lake producing 25,000 trees a year], we want each tree to find its home. When you go into the field, you can see the trees are happy. But if the deer ate the bottom, we'll cut it off 3 feet from the top, sell it as a table tree.

"People want a happy tree," he added. "It doesn't have to be perfect. It's part of nature. They're all individuals, like people."

Surely the business feels pride when they produce the Best Tree Ever and it goes to the White House or Rockefeller Center. That's like playing in the Super Bowl, no?

"The peak of it all, for me, is being out on the lots and seeing people with their families come in, happy," he said. "It's fun to have something in the Mall of America, but the home run is seeing the smiles when families pick one out."

You might suspect he likes his job.

"The sap got in my blood," Trent said. "The trees just grew on me."

If he meant that literally, there's probably a guy with a machete who could help him with that.