Subscribe for 33¢ / day
Bacteria-eating cheatgrass offered by county

Ravalli County Weed Coordinator Kellieann Morris checks out the cheatgrass growing in the borrow pit near the Daly Mansion. Her office is offering to place orders for area landowners who want to test a new product in which bacteria eats the cheatgrass seeds. 

Kellieann Morris has a new weapon in her battle against cheatgrass that she wants to share with other Ravalli County residents – a bacteria known as pseudomonas fluorescens.

A product using the bacteria has been tested for 20 years in Washington State, and last year Morris, the Ravalli county Weed District coordinator, was able to try it on two five-acre test plots, one in Hamilton and the other in Sula. She was pleased with the results, and believes this could be a significant tool in the county’s battle against its serious cheatgrass problem.

Basically, the bacteria eats the cheatgrass seeds, which eliminates the seed bank.

“We put one gallon per acre in Hamilton, and two gallons per acre in Sula,” Morris said. “With the two-gallon application, there is virtually no cheatgrass after one year. That’s not normal, though; it usually takes a couple years.”

The bacteria isn’t an herbicide; it occurs naturally in certain soils and inhibits the growth of cheatgrass. Known by researchers as ACK55, MB906 or D7, western land managers say the bacteria shows great promise.

“I’m convinced it will work as long as the bacteria are applied in the fall to the soil so they can colonize emerging cheatgrass roots in the spring,” Michael Gregg, a Land Management Research and Demonstration biologist at the Washington’s Mid-Columbia River Refuges Complex, said in a 2013 press release issued by the U.S. Fish and Wildlife Service.

At that time, the federal agency was trying to convince other agencies of the bacteria’s value in fighting cheatgrass. Morris wants to bring that battle to the local level.

She’s offering to place orders for landowners to purchase pseudomonas fluorescens at $10 per gallon. Landowners would have to apply it themselves this fall. She hopes to have the order in on Oct. 26, and it should arrive around Nov. 6.

There’s no limit on orders, and shipping is free.

Morris can’t guarantee that it will eradicate cheatgrass, but is cautiously optimistic based on the local results. It can be applied with sprayers mounted on anything from a backpack to a helicopter.

“The key is it needs to be put out when it’s cold, and you run the risk of equipment freezing up,” she cautioned. “But this thrives when it’s cold – under 50 degrees.”

In a field near the Daly Mansion, Morris pulls up a few handfuls of cheatgrass to show the green sprouts underneath. Those sprouts suck out all of the ground’s moisture, leaving none for native plants.

Cheatgrass covers hundreds of thousands of miles, and is spreading across thousands of acres every day, according to the U.S. Fish and Wildlife Service. Not only does it “cheat” the native plants out of their moisture in the spring, it also dries out quickly in the summer, allowing wildfires to burn hotter and more frequently.

“We’re basically offering this to the public at cost. They can put it on their property to test how it works,” Morris said. “The Bitterroot Valley and the rest of Montana is too beautiful to let the cheatgrass and other weeds take over.”

People interested in placing an order can contact Morris at 777-5842 or