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False Brome

Brachypodium sylvaticum
Updated Jul 27, 2023
 
1

Make a Positive Identification

  • False brome is an invasive, grassy weed found primarily in Oregon with small populations in Washington and California.
  • This perennial (lives many years) bunchgrass spreads quickly by seed.
  • False brome is expanding quickly in closed-canopy forests, woodlands, oak savannah, grasslands, roadside trails, and disturbed areas.
Species: False brome
False brome plant

Michelle Delepine, West Multnomah Soil & Water Conservation District

False brome germinates in late fall and spring. Plants mature into compact bunches of bright-green leaves (shown in photo) throughout spring, summer, and fall. Plants remain green in mild winter temperatures. In some colder winter locations, the leaves and stems die and become white thatch.

Species: false brome
False brome leaf blade with hairs on edge

"brachypodium sylvaticum" by Miguel Porto is licensed under CC BY-NC 4.0.

Leaf blades grow up to 0.5-inch wide. Stems and leaf edges (shown in photo) grow soft, short hairs.

Species: False brome
False brome flowers

False brome flowers in summer. Groups of flowers grow in pale green, drooping spikelets that are attached directly to the flowering stem. Spikelets are 1–2 inches long. There are 5–10 spikelets per flowering stem as shown in the photo. Each spikelet has 7–17 individual flowers.

Species: false brome
False brome seeds

Steve Hurst @ USDA-NRCS PLANTS Database

Individual false brome plants produce dozens to hundreds of seeds. Seeds are spread by animals, people, or equipment that move through infested areas. Most seeds germinate within a year or two.

Species: False brome
False brome growing in forest understory

Michelle Delepine, West Multnomah Soil & Water Conservation District

False brome is expanding quickly in closed-canopy forests, woodlands, oak savannah, grasslands, roadside trails, and disturbed areas.

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LOOK-ALIKES: NATIVE AND NON-NATIVE BROME SPECIES
Species: Other Brome Species

False brome grows nodding, bunching flower clusters (spikelets) similar to many other Bromus species. False brome is easily mistaken for the non-native weed Bromus diandrus (ripgut brome). It is similarly mistaken for the widely distributed and valuable native, Bromus vulgaris (Columbia brome).  

Telling the species apart requires a special identification key.

Control methods for these Bromus species are the same.

Your local Extension Specialist in Oregon  and other states  can identify grasses for you.

 
2

False Brome Benefits

  • False brome is a destructive weed. It doesn’t have any benefit for people or the environment.
 

False Brome Risks

  • False brome degrades habitat by suppressing native plant understory growth.
  • It has low palatability for grazing animals and degrades rangeland.
  • It is a host to a fungal species (Epichloe sylvatica). When the fungus is consumed, it is toxic to grazing animals.
  • It likely modifies fire regime in wildland and rangelands.
Risk Card
Does it cause harm?
Adults & Children
None
Property
High
Pets
None
Annoyance
High
Environment
High
Action Highly Recommended
 
3

TAKE ACTION

False brome is an invasive weed. It spreads quickly with seed.

Do I need to take action?  
Yes, false brome quickly dominates infested areas. Contact a specialist to correctly ID false brome and create a pest management plan.

What if I do nothing?  
False brome forms dense stands and is difficult to control. The longer you wait to act, the more difficult it will be to control it.

 
4

PREVENT FALSE BROME

False brome seedling growing in container

Tremello, CC BY-SA 3.0, via Wikimedia Commons

Look for Seedlings and Flowers
  • After you dig out false brome or treat it with herbicide, new seedlings may emerge the following spring.
  • The best false brome control is to prevent it from getting established. Monitor your property each year.

 

Gloved hands using metal brush to clean boots

Weston Miller, Oregon State University

Remove Dirt from Shoes and Equipment
  • After working or traveling in an area with false brome, clean your boots and tools.
  • Use a wire brush to remove all soil that may contain seeds.
  • Use a pressure washer to clean vehicles and heavy equipment after working in an infested area. Don’t work at a new site until the equipment is cleaned.
Landscape area with native plants growing densely together

Weston Miller, Oregon State University

Replant with Technical Support
  • False brome is difficult to expel from an infested area. Replanting a previously infested area requires planning and effort.
  • Create a multi-year revegetation plan. Plans include site preparation and planting details, plant care, and follow-up control for false brome and other weeds. Plan for at least 2–3 years of monitoring and maintenance.
  • Your local Extension specialist, soil and water conservation district, or a professional revegetation specialist can suggest strategies for your area.
 
5
Solutions for False Brome

Early Detection & Rapid Response

Watch for false brome on property you manage. Remove it before it becomes a bigger problem.

Physical Removal of Plants & Non-chemical Methods

  • Pull out small patches, and remove the root. Plants are weakly rooted and seeds are short lived.
  • Repeated mowing helps keep false brome from making new seed.

Herbicides (Weed Killers)

Herbicides effectively control false brome when used according to the label instructions.

Monitoring & Follow Up

  • Restore the area by planting native trees and shrubs to shade out false brome. Monitor the area and re-treat as needed.
  • It takes repeated effort over several years to get rid of a large, established stand of false brome.

NEED HELP?

Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon  and other states  can suggest other methods.

Jump to

Method Does it work? Is it safe? Recommendation
A
Physically Removing Plants & Mowing
Effective
Low risk
Recommended
B
Glyphosate & Grass-Selective Herbicides
Effective
Moderate risk
Use if Necessary
C
If Using Herbicides, Protect Yourself & Minimize Risks
 
A

Physically Removing Plants & Mowing

Non-Chemical Method

Weston Miller, Oregon State University

Physically Removing Plants & Mowing

Recommended
  • Dig out individual plants and small patches.
  • Repeated mowing helps keep false brome from making new seed.
Does it work?
Effective

Use preventive measures for best results.
How much effort?
High effort

Requires several years of monitoring and effort.
What's the risk?
Low risk
Possible risk of exposure or harm from chemicals
NONE
False brome specimen showing root system

Pull out small and large patches, making sure to remove the root. Stem fragments can sprout roots and form new plants. The photos shows a false brome specimen, including the root system.

Worker with string trimmer

kn1, iStock

Mowing alone is not recommended to control false brome. It will regrow following limited mowing. However, repeated mowing will provide control if done several times throughout the growing season to prevent flower cluster growth and weaken plants.

Soil Disturbance and Erosion

  • Minimize soil disturbance as much as possible.
  • Regrade the soil after digging up false brome plants. Apply mulch (when appropriate).
  • Take steps to prevent erosion as needed.
  • Replant the area to shade false brome seedlings.
 
B

Glyphosate & Grass-Selective Herbicides

Chemical Method: Use with caution

Chameleonseye, iStock

Glyphosate & Grass-Selective Herbicides

Use if Necessary

Herbicide products that contain active ingredients glyphosate and herbicides that target grasses (grass-selective) are effective treatments for false brome when label directions are followed. Herbicides that kill germinating seedlings (preemergent) also work. False brome requires several years of monitoring and treatment.

Does it work?
Effective

Use preventive measures for best results.
How much effort?
Moderate effort

False brome requires several years of monitoring and treatment to eliminate.
What's the risk?
Moderate risk
  • Herbicides come with real risks. ALWAYS read the entire label front to back. Review instructions even for brands you know.
  • Herbicides can run off your site into waterways and may harm wildlife. See How to Keep Pesticides Out of Waterways.
Possible risk of exposure or harm from chemicals
El uso de herbicidas conlleva cierto grado de riesgo. El riesgo más bajo se presenta con el uso de métodos alternativos.

You may be exposed to an herbicide if you:

  • Get it on your skin
  • Breathe it in
  • Eat or smoke afterward without washing hands
  • Touch or eat plants that are wet with spray (you, pets, or children)
  • Bring it inside on your shoes or clothes

Follow directions closely to reduce risk.

Herbicide products containing active ingredient glyphosate and grass-selective herbicides such as fluazifop effectively control false brome when label instructions are followed. Look for these chemical names in the “Active Ingredients” section of product labels.

Photo of herbicide label highlighting active ingredient glyphosate

Weston Miller, Oregon State University

  • The white box on the example label highlights active ingredient glyphosate. Text on the label states “Kills grasses and weeds around flower beds....”
  • Glyophosate will damage most plants and grasses. Don’t let the spray contact plants you want to keep.
Photo of herbicide label highlighting active ingredient fluazifop

Weston Miller, Oregon State University

  • Grass-selective herbicides such as fluazifop effectively control cheatgrass.
  • These products don’t injure desired plants when used as directed on the label instructions. They can be used around ground covers, flower beds, and shrubs (bushes), and trees.
  • The white box on this example label highlights active ingredient fluazifop. Text on the label states “KILLS WEEDY GRASSES WITHOUT INJURING ORNAMENTAL PLANTS.”

Herbicide Application Tips

  • Premixed products are available in stores.
  • Preemergent herbicide products applied to the soil surface in late summer through winter are effective for preventing false brome seeds from growing.
  • The specific timing and application method depends on the herbicide product. Follow the label instructions for best results.
  • It takes repeated efforts over several years to get rid of a well-established stand of false brome.
  • Other herbicides are available for false brome control when used in an integrated pest management plan. Consult with pest control specialists for access to other herbicides and to generate an integrated pest management plan.
 

If Using Herbicides, Protect Yourself & Minimize Risks

Chemical Method: Use with Caution
Ducks in marsh

SteveOehlenschlager, iStock

Why is it important to read herbicide labels?

  • They have detailed information on how to use the product correctly and legally.
  • They contain information on potential hazards of the product.
  • They provide instructions you should follow for poisonings and spills.
  • Following label instructions helps to minimize the risks and maximize the benefits.

Key Herbicide Safety Tips

  • Read the entire label front to back.
  • Follow the instructions.
  • Review the instructions even for brands you know.
  • Only apply the product where the label says it may be applied.
  • Be precise in your application. More is not better.

The Label is the Law

ALWAYS read the label before using herbicide products. The label is a legal document that provides information on how to safely use the herbicide. This helps avoid harm to human health and the environment. Using an herbicide in off-label ways is illegal. It can result in legal enforcement actions.

READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.

  • Labels are different for every product and they often change over time.
  • Use a magnifying glass for small print.
  • Pay attention to CAUTION, WARNING, and DANGER statements.
  • Pay attention to the PRECAUTIONARY STATEMENTS.
  • The law states you must read and follow herbicide instructions.

Protect Yourself
Eye, skin & lung irritants

  • Wear the right protective gear. This often includes chemical-resistant gloves, safety glasses, a long-sleeve shirt, pants, socks, and shoes.
  • Mix outdoors or in a well-ventilated area.
  • Wash hands after mixing or applying, and before eating or smoking.
  • Take a shower immediately after handling herbicides.
  • Wash clothes worn while mixing or applying separately from other laundry.

Protect Children & Pets
Children and pets are at risk if they eat or touch the plants before it dries.

  • Keep them away during and after applying herbicides (read label for how long).
  • Remove toys and pet dishes from yard before applying.
  • Don’t track herbicide products into your home on shoes or clothes.

Don’t Spray into Water

  • It’s illegal to apply herbicides in a stream or slow moving/wetland pool.
  • You need a product registered for aquatic areas. This includes waterways, ditches, drains, and other places where water collects.

Protect Plants You Want to Keep

  • Glyphosate and similar herbicide ingredients damage both grass and broadleaf plants.
  • Minimize spraying of foliage, stems, exposed roots, or the trunks of desirable shrubs or trees to avoid harm.
  • Follow the label to avoid damaging the roots of trees and shrubs.

Avoid Wet, Windy, or Hot Weather
Use during favorable weather for best results.

  • Don’t spray when it’s raining or when rain is expected in the next 24 hours.
  • Wind causes spray to drift that can get on you and desired plants.
  • Herbicides may be less effective in hot weather if the target plants are moisture-stressed.
  • Some herbicides can turn into a vapor in hot weather and damage nearby plants.

Storage & Disposal

  • Store in a secure area away from children.
  • Don’t put unused herbicide products in the trash.
  • Never pour down any drain or waterway.
  • Take unused herbicides to a hazardous waste facility.

Call  1-800-CLEANUP (1-800-253-2687) to find out where to dispose of herbicides.

For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call  503-234-3000, email   or visit Metro’s website  

More about:

About Using Pesticides on School Grounds in Oregon

If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management  (Oregon Department of Agriculture).

NEED HELP?

The National Pesticide Information Center (NPIC)  can answer questions about pest control chemicals.
 1-800-858-7378 or npic@ace.orst.edu  

Consider using a licensed pest or weed control company. Learn How to Hire a Pest Control Company.

Your local Extension Specialist in Oregon  and other states  can suggest other methods.

Invasive Species Alert

  • Invasives are non-native species that spread aggressively and alter the environment.
  • Controlling unwanted false brome is costly.
  • Please do your part to control it on property you manage. It can spread beyond your property and adversely impact your neighbors.

If you think you’ve found false brome in the grey areas of this map, please report it to the Oregon Invasive Species Hotline at:  1-866-INVADER (1-888-468-2337) or use their online reporting form  

open Map static invasive map
Invasive species data @ 2022, iMapInvasives (NatureServe)

If you find false brome in a new area (orange shows already reported cases), please report it  

View Larger Map >
SEE OTHER COMMON PACIFIC NORTHWEST WEEDS

Content provided by editor Weston Miller and writer J. Jeremiah Mann. Pesticide safety information edited by Kaci Buhl.

 Peer reviewed by OSU Department of Horticulture.

Photo of Weston Miller

Weston Miller

Project Founder and Content Writer

Weston Miller served as Community and Urban Horticulture faculty for Oregon State University Extension Service for Clackamas, Multnomah, and Washington Counties. Weston is an author for content for this website. He developed funding partnerships with Portland area agencies to initiate and build out the Solve Pest Problems website focused on this goals:

J. Jeremiah Mann

J. Jeremiah Mann

J. Jeremiah Mann completed a Physical Science undergraduate degree at Humboldt State University, and M.S, Ph.D focusing on plant science topics at UC Davis. He went on to work for the Natural Resources Conservation Service and in a leadership position serving a private agricultural technology company. He currently lives in Sacramento California where he consults on pest and property management topics.

Photo of Kaci Buhl

Kaci Buhl

At the state level, I lead the Pesticide Safety Education Program (PSEP). The program hosts live recertification events around the state, serving over 1,000 licensed pesticide applicators each year. We also produce web-based training modules and license-preparation study manuals. Special training for unlicensed pesticide applicators is also available through a grant from the USDA Specialty Crop Block Grant Program. The PSEP at OSU works closely with the Oregon Department of Agriculture's Pesticides Division.

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