Look out, noxious weeds — Washington County is on the hunt.

The annual chemical spraying of 220 miles of rural roadsides will begin July 22. The main target? Tall purple stalks of Canadian thistle, said Doug R. Johnson at the county's public works department.

"They can take over ditches and pastures," he said. "It's an invasive weed. We try to keep them at bay."

The county will spray the chemicals Telor and Tordon 101, but only when property owners don't object. Sometimes, residents with bee colonies and organic gardens ask that no spraying be done nearby, Johnson said. The county does "spot spraying" only where Canadian thistle, wild parsnips and other invasive weeds are found, he said.

"It isn't like we turn on the gun and go," he said.

Tests have shown that livestock can't consume enough treated foliage to cause physical harm, he said.

"Do Not Spray" signs are available at the county shop at 11660 Myeron Road N., Stillwater, or call 651-430-4389.

Kevin Giles

@stribgiles