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Yellow Archangel

Lamiastrum galeobdolon
Updated Nov 04, 2022
 
1

Make a Positive Identification

  • Yellow archangel is a fast-growing perennial (lives many years) herbaceous (soft leaves and stems) plant. It was widely planted in landscapes the Pacific Northwest.
  • It has escaped from landscapes and is quickly spreading into adjacent forested areas.
  • This shallow rooted plant grows one to two feet tall. It forms a dense mat that excludes other plants.
  • Yellow archangel is difficult to control. Take action to kill this invasive plant and prevent its spread.
Yellow Archangel
Species: Yellow archangel
Yellow archangel with variegated leaves

Rob Routledge, Sault College, Bugwood.org

Yellow archangel’s leaves are hairy and toothed. They grow opposite each other along the stem. Its leaves are often variegated with silver-green markings.

Species: Yellow archangel
Yellow archangel with whorls of yellow flowers

Some yellow archangel plants have green leaves. All plants of this species have yellow flowers as shown in the photo.

Species: Yellow archangel
Stem layering illustration

University of Maine

Once yellow archangel is established, it spreads via stem layering. When nodes on the stem contact the ground or get buried, they sprout roots. The line drawing shows layering. Stem fragments can also take root and establish new plants. Yellow archangel also spreads by seed.

Species: Yellow Archangel
Yellow archangel mat

Yellow archangel forms a dense mat when allowed to establish in an area.

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LOOK-ALIKE: GOUTWEED
Species: Goutweed
Variegated goutweed leaves

Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Some cultivars of goutweed (Aegopodium podagraria) have variegated leaves. Variegated goutweed leaves look similar to variegated yellow archangel leaves. Goutweed’s leaves have a central stem with leaflets. Yellow archangel has opposite leaves.

Goutweed is a species of concern. It spreads in gardens and is hard to control. Its sale is prohibited in several New England states. It is recognized by natural resource professionals as a potentially invasive plant in the Pacific Northwest.


Take action

Goutweed is an aggressive weed that takes over areas. Take action to control it. Solutions for yellow archangel will also work for goutweed.

 
2

Yellow Archangel Benefits

  • Yellow archangel is an invasive weed. It doesn’t have any benefits for people and the environment.
 

Yellow Archangel Risks

  • If left unmanaged, yellow archangel forms a dense mat of stems and leaves that smothers other plants.
  • It has little food value to native animals and insects.
  • Yellow archangel reduces the habitat value of an area by excluding native plants.
Risk Card
Does it cause harm?
Adults & Children
None
Property
High
Pets
None
Annoyance
High
Environment
High
Action Highly Recommended
 
3

Take Action

If you have yellow archangel on your property, take action to control it and limit its spread.

Do I need to take action?

  • Yes. Remove individual plants and small patches. Established patches require several years to control.
  • Yellow archangel is currently sold by nurseries and online. Don’t buy this invasive species or plant it in your landscape.

What if I do nothing?
Yellow archangel patches will keep spreading and become more difficult to control.

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.

 
4
Solutions for Yellow Archangel

Early Detection & Rapid Response

Watch for yellow archangel on property you manage. Remove it before it becomes a bigger problem.

Physical Removal of Plants & Non-Chemical Options

  • Dig out plants and sift the soil for roots and stem fragments.
  • Yellow archangel will regrow from broken stem and root fragments. Dispose of yellow archangel stems and roots in the green waste stream.

Herbicides (Weed Killers)

Herbicides effectively control yellow archangel when used according to the label instructions.

Monitoring & Follow-up

  • Following removal, return to the area every several months. Look for regrowth and seedlings. Take action as needed. Established plants require several years of follow-up control actions.
  • After you remove yellow archangel, new plants will grow in the same spot unless you take steps to prevent them.

Jump To

Method Does it work? Is it safe? Recommendation
A
Physically Remove Plants
Effective
Low risk
B
Herbicides Triclopyr & Glyphosate
Effective
Moderate risk
Use if Necessary
C
If Using Herbicides, Protect Yourself & Minimize Risks
D
Prevent Yellow Archangel
 
A

Physically Remove Plants

Non-Chemical Method

University of Maine

Physically Remove Plants

Dig out plants. Sift soil and remove stem and root fragments.

Does it work?
Effective
  • It’s challenging to remove all of the root pieces from the soil. Expect to regrow.
  • Use preventive measures for best results.
How much effort?
High effort
  • Hand-pull and dig plants when the soil is moist. Mowing is not recommended.
  • Dispose of plants in sturdy plastic bags in the trash.
What's the risk?
Low risk
Possible risk of exposure or harm from chemicals
NONE

Tips for Removing Yellow Archangel

  • Yellow archangel is shallow-rooted so it can be dug up with hand tools.
  • Take care to remove all root and stem fragments.
  • It is easiest to remove yellow archangel plants during fall through spring when the soil is moist.

Soil Disturbance & Erosion

  • Minimize soil disturbance as much as possible when removing yellow archangel.
  • Regrade the soil after digging roots. Apply mulch (when appropriate).
  • Take steps to prevent erosion as needed.
  • Replant the area to shade blackberry seedlings.
Curbside green waste bin

Weston Miller, Oregon State University

Composting yellow archangel is not advised. Root and stem fragments lying on the soil surface will make new plants. Put yellow archangel plant material into the green waste stream such as the curbside recycling bin shown in the photo.

 
B

Herbicides Triclopyr & Glyphosate

Chemical Method: Use with caution

iStock

Herbicides Triclopyr & Glyphosate

Use if Necessary

Herbicides that contain the active ingredients triclopyr and glyphosate effectively control yellow archangel when used according to label directions.

Does it work?
Effective
  • It requires several years of monitoring and effort to get rid of yellow archangel.
  • Use preventive measures for best results.
How much effort?
Moderate effort
  • Treat individual field yellow archangel plants and patches.
  • Return to the area each year and take action as needed.
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
Using herbicides includes some amount of risk. The lowest risk comes with using alternative methods.

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.

Herbicides with active ingredients triclopyr and/or glyphosate, used individually or in a mixture, are effective chemical treatments for yellow archangel. Look for these chemical names in the “Active Ingredients” section of product labels.

Photo of herbicide label highlighting active ingredient triclopyr

Weston Miller, Oregon State University

  • The white box on the example product label highlights active ingredient triclopyr. Text on the label states “Kills completely.”
  • Triclopyr doesn’t injure most grasses. It’s a good choice for treating yellow archangel growing next to desired grasses in lawn, pasture, and meadow areas.
Photo of herbicide label highlighting active ingredient glyphosate

Weston Miller, Oregon State University

  • The white box on the example label highlights active ingredient glyphosate. The text on the label states “Kills grass and weeds around flower beds, trees, shrubs....”
  • Glyphosate will damage most plants and grasses. Don’t let the spray contact plants you want to keep.

Herbicide Application Tips

  • Apply herbicide to yellow archangel when it is actively growing from spring through fall.
  • Herbicide treatments are less effective if the plants are stressed due to lack of water.
  • Expect that yellow archangel will regrow after treatment with herbicides. Look for regrowth and retreat as needed.
 

If Using Herbicides, Protect Yourself & Minimize Risks

Chemical Method: Use with Caution
Great blue heron in marsh

BrianLasenby, 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 you 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 if needed.
  • 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.

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.

 

Prevent Yellow Archangel

Look for Yellow Archangel Seedlings and Regrowth
  • Return to the site after control activities and look for regrowth. Yellow archangel regrows from cut stems, stem fragments and roots. Take action as needed.
  • Look for yellow archangel seedlings as shown in the photo.
Gloved hand using metal brush to clean shovel

Weston Miller, Oregon State University

Remove Dirt from Shoes and Equipment
  • After working or traveling in a patch of yellow archangel, clean your boots and tools. Use a wire brush to remove soil and seeds.
  • If you drive into the yellow archangel stand, clean your vehicle afterward.
Landscape area with native plants growing densely together

Weston Miller, Oregon State University

Install New Plants
  • Take care of the plants to get them established and suppress yellow archangel regrowth.
  • Replanting stabilizes the soil surface, shades yellow archangel seedlings, and creates habitat.
  • A yellow archangel infestation and removal activities may significantly damage a site. There may be few or no remaining desirable plants.
  • 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.

Invasive Species Alert

  • Invasives are non-native species that spread aggressively and alter the environment.
  • Controlling unwanted yellow archangel is costly.
  • Please do your part to control it on property you manage. Yellow archangel can spread beyond your property and have an adverse impact on your neighbors.

If you think you’ve found yellow archangel 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 yellow archangel in a new area (orange shows already reported cases), please report it  

View Larger Map >

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.