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Jubatagrass & Pampasgrass

Cortaderia jubata, C. selloana
Updated Nov 04, 2022
 
1

Make a Positive Identification

  • These are two species of large perennial grasses from South America. They grow dense tufts (bunches) of leaves 3–13 feet tall. They have plumes of flowers up to 6 feet taller than the leaves. Jubatagrass and pampasgrass are difficult to tell apart.
  • Invasive populations have escaped from landscape plantings. They are spreading throughout Western coastal states.
  • Both grasses establish and thrive in coastal sites. Pampasgrass tolerates warmer and drier interior sites.
Jubatagrass
Species: Jubatagrass
Jubatagrass infestation

Jubatagrass grows in moist, cool coastal areas. It is found in dunes, drainage ditches, roadsides, cut slopes, forestry operations, and disturbed areas.

Species: Jubatagrass
Jubatagrass leaves

Mature leaves are 0.8–1.2 inches wide and grow 3–6 feet above the ground. Bright green leaves ascend and spread horizontally. Leaf edges are sharp and can easily cut exposed skin.

Species: Jubatagrass
Jubatagrass immature flowering plumes

Immature flowering plumes of jubatagrass are deep violet and can grow 3–6 feet above leaves. Plumes occur in late summer-early fall.

Species: Jubatagrass
Jubatagrass mature plume and seeds
  • Mature flowering plumes of jubatagrass fade to pinkish or tan color. Jubatagrass flowers are effectively all female; however, plants produce viable seeds.
  • Each jubatagrass flowering plume can create roughly 100,000 seeds. An individual plant creates millions of seeds per year.
  • Seeds are less than 0.1 inches long and are dispersed on air currents, animals, clothes, and equipment.
Species: Jubatagrass
Cortaderia seedling

Joseph M. DiTomaso, University of California - Davis, Bugwood.org

Seeds live less than six months and require moist bare ground in spring to germinate and grow new plants. Seedlings compete poorly with native plants in shady conditions.

Species: Jubatagrass
Jubatagrass root crown

Forest & Kim Starr, CC BY 3.0 US, via Wikimedia Commons

Mature jubatagrass forms a robust root system that often requires heavy equipment to remove.

Pampasgrass
Species: Pampasgrass
Cortaderia jubata, C. selloana

John Ruter, University of Georgia, Bugwood.org

Pampasgrass is often grown in landscapes as shown in the photo.

Compared to jubatagrass, pampasgrass plants in landscapes don’t always create viable seeds.

If you have pampasgrass in your landscape, look for new seedlings in bare-ground areas. If you don’t see new seedlings, then you can leave the plants alone. If you do see new seedlings, then remove the pampasgrass plants from your landscape.

Species: Pampasgrass
Pampasgrass immature flowering plumes

"Pampasgras" by Ronile35 is licensed under CC BY-NC-SA 2.0.

Immature flowering plumes of female pampasgrass are white and grow 0–3 feet above leaves. The male flowering plumes are white-violet and grow 0–6 feet above leaves. Plumes occur in midsummer–early fall.

The immature plumes of jubatagrass are violet-colored in comparison.

Species: Pampasgrass
Pampasgrass stand growing in inland site

When both male and female pampasgrass flower heads grow together, they form viable seeds. In this case, it spreads to new areas, which makes it an invasive plant species.

Pampasgrass grows in moist, cool coastal areas and tolerates a wider range of cool and warm temperatures than jubatagrass.

Pampasgrass grows in the increased sunlight intensity and drought found at inland sites. It grows in dunes, drainage ditches, roadsides, cut slopes, forestry operations, and disturbed areas.

LOOK-ALIKES: RAVENNA GRASS & Native Reed Grasses
Species: Ravenna Grass
Ravenna grass in landscape

Ravenna grass (Saccharum ravennae) could be confused with jubatagrass or pampasgrass. Its flower plumes grow up to 12 feet tall. It is also planted in landscapes as shown in the photo.

To tell this grass apart from jubatagrass and pampasgrass, look at the base of the leaf blades. Ravenna grass has fuzzy hairs that cover the base of the leaf (ligule).

Different risks or methods

Ravenna grass is a noxious weed with limited distribution in Eastern Oregon. Take action to control it. See Oregon Department of Agriculture Noxious Weeds  for more information.

Species: Native Reed Grasses
Reed grass (Calamagrostis nutkaensis) with loose flower plume

USFWS Mountain-Prairie, Public domain, via Wikimedia Commons

Some native reed grasses (Calamagrostis spp.) are large, perennial grasses found in coastal areas. They grow 5–6 feet tall.

Young pampasgrass and jubatagrass without plumes may be confused with mature reed grass. Reed grasses have shorter plumes.

Different risks or methods

Reed grasses are native species. They may be left alone.

 
2

Jubatagrass & Pampasgrass Benefits

  • When male and female pampasgrass plants are grown apart, they don’t produce viable seed. In this situation, pampasgrass is an attractive landscape plant.
  • When jubata and pampas are allowed to spread by seed, they are destructive weeds that don’t have any benefits for people and the environment.
 

Jubatagrass & Pampasgrass Risks

  • These grasses form dense stands with sharp leaves.
  • They crowd out desired vegetation, impede site access, and increase fire risk.
  • Jubatagrass and pampasgrass form dense stands that have a negative impact on forestry operations.
Risk Card
Does it cause harm?
Adults & Children
Some
Property
High
Pets
Some
Annoyance
High
Environment
High
Action Highly Recommended
 
3

TAKE ACTION

If you have jubatagrass or pampasgrass spreading on your property, take action to control it right away.

Do I need to take action?

Yes. Report infestations. Remove individual plants and small patches. Removal of established patches often requires a combination of herbicide, power tools, and heavy equipment.

What if I do nothing?
Jubatagrass and pampasgrass spread rapidly by seed. They take over areas with the passing of time.

 
4

PREVENT JUBATAGRASS AND PAMPASGRASS

Single jubata grass plant
Watch for New Plants on Your Property
  • The best control of these grasses is to prevent them from getting established.
  • Monitor your property each year. Look for individual plants such as the one in the photo.
Cortaderia seedling

Joseph M. DiTomaso, University of California - Davis, Bugwood.org

Look for Seedlings and New Growth
  • After you dig out pampasgrass and jubatagrass or treat it with herbicide, look for plants that have re-rooted and new shoots.
  • New seeds may also germinate as shown in the photo.
Gloved hand with wire brush cleaning shovel

Weston Miller, Oregon State University

Remove Dirt from Shoes and Equipment
  • After working or traveling in an area with pampasgrass or jubatagrass, clean your boots and tools.
  • Use a wire brush to remove all soil that likely contains 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 has been cleaned.
Restoration area with native plants

Weston Miller, Oregon State University

Replant the Area
  • Plant vigorous native plants to compete with Cortaderia seedlings. Thick mulch will prevent seedlings from establishing.
  • These grasses are difficult to eliminate 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 Cortaderia and other weeds. Plan for at least 2-3 years of monitoring and maintenance.
  • If this is the situation then a multi-year revegetation plan is needed. Your local Extension specialist, soil and water conservation district, or a professional revegetation specialist can suggest strategies for your area.
 
5
SOLUTIONS FOR JUBATAGRASS & PAMPASGRASS

Early Detection & Rapid Response

Watch for jubatagrass and pampasgrass on property you manage. Remove it before it becomes a bigger problem.

Physical Removal of Plants & Non-Chemical Options

Single plants and small patches can be removed with hand tools and power tools. Remove or kill all of the root crown.

Herbicides (Weed Killers)

Herbicides effectively control these grasses when used according to the label instructions.

Monitoring & Follow-Up

  • Look for new jubatagrass and pampasgrass on your property each year.
  • After you remove these grasses, new plants will grow in the same spot unless you take steps to prevent them.

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 Remove Plants
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 Remove Plants

Non-Chemical Method

"starr-100303-3223-Cortaderia_jubata-small_plant_pulled_out-Polipoli-Maui" by Starr Environmental is licensed under CC BY 2.0.

Physically Remove Plants

Recommended

Dig out small grasses and remove the root crown with tools. Use equipment as needed for larger grasses.

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

Leaves can cut exposed skin. Wear a long-sleeved shirt and gloves.
Possible risk of exposure or harm from chemicals
NONE

Removal of large individuals in established stands requires power equipment such as chainsaws and string trimmers. These tools remove the leaves to expose the root crown. Then plants are dug out with an excavator or backhoe.

Cortaderia sp. root crown
  • Pampasgrass and jubatagrass spreads with seeds that need moist bare ground to germinate and establish. These seedlings quickly grow to large tufted individuals with robust root systems.
  • The photo shows a small plant dug out of the ground.
  • Dug-out plants with intact roots left on moist soil can re-root. Make sure the detached plants have no contact with soil.
Power tools and heavy equipment for digging

Kn1, iiStock

  • Chainsaws, string trimmers (shown in photo), or bladed tools will remove grass leaves to expose the root crown.
  • Interrupt seed production by removing the flowers before they mature.
Backhoe removing grasses along highway

David Chang, Santa Barbara Agricultural Commission

Heavy equipment is useful to dig out large perennial grasses, as shown in the photo.

 
B

Glyphosate & Grass-Selective Herbicides

Chemical Method: Use with caution

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 jubatagrass and pampasgrass when label directions are followed.

Does it work?
Effective

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

Several years of monitoring and treatment may be necessary to eliminate jubatagrass or pampasgrass.
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.

Natural resource management professionals use herbicide products that contain glyphosate and grass-selective herbicides such as fluazifop. These products, used individually or in a mixture, are effective chemical treatments for jubatagrass and pampasgrass control. 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 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.
  • A silicon-based surfactant (chemical that helps herbicide penetrate leaves) may provide greater effectiveness.
Photo of herbicide label highlighting active ingredient fluazifop

Weston Miller, Oregon State University

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

The photo shows a jubatagrass plant successfully killed with herbicide.

Herbicide Application Tips

  • Premixed products are available in stores.
  • Specific timing and application methods depend on the herbicide product. Follow the label instructions for best results.
  • It may require repeated applications to get rid of a well-established stand of these grasses.
  • For very large clumps, cut and remove the top foliage, then treat the regrowth. This method reduces the amount of herbicide needed compared with herbicide treatment alone.
  • Forestry operations have used the herbicide hexazinone (Velpar or Pronone) to control pampasgrass. This herbicide is root-absorbed. It should be applied by a licensed pesticide applicator.
 

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 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.

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.
  • Control of jubatagrass and pampasgrass (invasive) is costly.
  • Please do your part to control it on property you manage. It can spread beyond your property and impact your neighbors.

If you think you’ve found jubatagrass and pampasgrass 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)

The map shows the distribution of jubatagrass and pampasgrass (combined) in Oregon. If you find jubatagrass and pampasgrass 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.

Pampasgrass and Jubatagrass Threaten California Coastal Habitats  (PDF)
University of California WEED Research & Information Center

Jubata Grass  
Washington Noxious Weed Control Board

Weed Control User Tool  
University of California ANR