The Canadians are coming, and they're bringing more than maple syrup.

While right-wing commentators complain about immigrants from south of the border after the raid June 12 at Portland's Del Monte Fresh Produce plant, in the past year Portland cops have busted a string of high-tech marijuana grows that authorities link to Asian crime rings from north of the border—British Columbia.

"It came out of nowhere," says Jose Cienfuegos, a deputy Multnomah County district attorney. "We're just getting a handle on it now."

Since last August, local cops have raided 22 Portland homes in five separate sting operations. Each house had been converted into a massive marijuana-growing operation. All were owned by Vietnamese immigrants who authorities say were recruited by crime rings based in Vancouver, B.C.

"We're not talking about the mom-and-pop, 25 plants in your basement," says Portland Police Officer Scott Groshong. "It's a more sophisticated commercial growing method where they're growing it as fast as they can."

About half the growers busted are U.S. citizens, says Groshong, a member of the Regional Organized Crime/Narcotics Task Force. The others, he says, hold Vietnamese passports. Because the United States lacks an extradition agreement with Vietnam, Groshong says the Vietnamese nationals will face justice here, and if convicted, imprisonment as well.

Cienfuegos says one of the growers was Canadian, but it's unclear yet what will happen to that person.

The most recent bust came June 11, when members of the Multnomah County Sheriff's Special Investigations Unit swept into a family home at 14910 NE Alton St. and found over 200 pot plants. Later that day they raided another home, at 6606 SE 93rd St., with 300 plants.

The owner of both homes, 44-year-old Thanh Van Nguyen, was indicted June 15 in Multnomah County Circuit Court on six felonies, including manufacturing and delivering marijuana. He faces up to 20 years in prison, if convicted on all counts, and remains in custody on $220,000 bail.

That followed a string of busts in the past year, mostly in middle-class homes on Portland's east side.

Cops first get tipped off because the homes are stealing power. Once inside they find the houses completely rewired, with electricity flowing from jury-rigged transformers to banks of high-powered lights. Irrigation systems water the plants, foil tubes funnel excess heat out the chimney, and insulation over the windows maintains a constant temperature.

"The operation really encompasses the entire home," Cienfuegos says. "We're talking every single floor—even the garage—is somehow used for the cultivation of marijuana."

That causes extensive damage to the homes, he says. Once they're busted, the growers default on their mortgage. Banks are left with a house that's unusable because of holes in the wall, mold infestation and mounds of dirt on the floor.

Cienfuegos says the pot houses have "a detrimental effect on the other houses in the neighborhood. [And] we're talking about some decent neighborhoods."

The B.C. gangs often recruit Vietnamese people they find gambling at U.S. casinos with a promise of easy money and a crash course in how to grow, Groshong says. The equipment is mostly imported from Canada and sold commercially in Seattle.

Some of the homes are lived in. Others are visited only periodically by the growers, who keep their grow-lights on timers. Excess heat is channeled out the chimney so police using infrared devices see nothing unusual.

Start-up costs include down payments on the homes ($30,000-$45,000) and up to $15,000 in equipment for each house. Once the operation's up and running, each home turns out about a 20-pound crop every 90 days, Groshong says.

That gets sold for up to $3,500 a pound and shipped across the United States. If you don't have your calculator handy, that's as much as $280,000 a year made per house.

The growers take about 25 percent and send a portion back to Vietnam, Groshong says. The rest goes to the gangs in B.C.

British Columbia's growing rings began moving operations south several years ago to avoid the danger of shipping pot across the Canadian-American line, says Kenneth Magee, assistant special agent in charge of the U.S. Drug Enforcement Administration in Portland. "It's migrating from Canada to Washington to Oregon," he says.

Most pot in the U.S. used to come from Mexico and the Caribbean. But when border controls tightened after the 9/11 attacks, more cultivation went domestic. Cops soon caught on to big outdoor grows, pushing growers inside. Nationwide, indoor pot seizures have doubled in the past three years to 400,000 plants in 2006, according to the DEA.

Groshong expects more such busts in Portland. "I believe that we have just the tip of the iceberg," he says, "since the financial incentive is just so great."

Items from one of the homes: