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New invasive grass makes its way to JBLM

‘This is possibly the most invasive plant ever introduced to Washington state’

Fish and Wildlife interns deadhead false brome in JBLM training areas to remove seed heads June 17. Photo credit: Rod Gilbert, JBLM Directorate of Public Works

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JOINT BASE LEWIS-MCCHORD - Joint Base Lewis-McChord has its share of invasive plants, such as scotch broom and Himalayan blackberry, which are easy to spot.

There are protocols in place to address the impacts; however, in April 2021, Brachypodium sylvaticum or false brome, a Class A noxious weed, was found in one of the JBLM training areas.

False brome is a perennial bunch grass native to Eurasia and North Africa that generally stays green throughout the year. It resprouts quickly after fire, thrives at elevations of 200 to 3,500 feet and is shade-tolerant and drought-resistant.

"This is possibly the most invasive plant ever introduced to Washington state and will form pure stands - displacing all other vegetation if not eradicated," said Bruce McDonald, JBLM forester with the Environmental Division, Directorate of Public Works. "It occurs in open meadows, prairies, oak woodlands and any forest type - both coniferous and deciduous."

False brome was first seen in Oregon in 1939 at Willamette Valley. Researchers estimate since then, it has taken over at least 10,000 acres of meadows and oak woodlands in Linn and Benton counties in Oregon.

False brome has been seen in Washington state in Whatcom, Cowlitz and King counties, where it is listed as a Class A noxious weed. Class A noxious weeds are non-native species that are highly-invasive and have limited distribution in Washington.

Preventing new infestations and eradicating existing infestations are the highest priority, McDonald said.

Integrated Training Area Management, JBLM Forestry and Fish and Wildlife have been working together to survey locations of the plant. Once locations are identified, crews work to cut off seed heads and spray existing plants with herbicide.

Locations where false brome has been located may have new access restrictions for training missions and recreational use. False brome seeds are spread by shoes, vehicle wheels, birds and deer - when the awned seeds get stuck in their coats.

To help control and isolate the plant, strategies may involve roadside and broadcast spraying of herbicides and washing vehicles before and after going into certain training areas.

The Washington State Noxious Weed Control Board and JBLM staff are working together and will notify the local community to be on the lookout for outbreaks.

As described on the NWCB's website, false brome is "a perennial, loosely tufted grass with upright stems. Hairs on leaves, leaf sheaths and nodes are noticeable but variable. Plants often have a distinctive lime-green coloration that persists much of the year."

The JBLM community is encouraged to be aware of area and road closures, as to not inadvertently spread the false brome.

"The best way to not spread false brome is to stay out of known areas that have infestations," McDonald said. "If a person or animal is going through known locations of false brome, it is best to clean off your boots or hooves before going to another area."

This will help protect JBLM's prairies, oak woodlands and forest, he said.

To report a sighting of false brome on JBLM, send an email to the JBLM Environmental Division at

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