Non-native Plants

Quackgrass

Elymus repens

USDA symbol: ELRE4

perennial grass

Alaska: non-native, naturalized
Canada: non-native, naturalized
Greenland: non-native, naturalized
Lower 48 states: non-native, naturalized
St. Pierre and Miquelon: non-native, naturalized

If you’ve ever battled a stubborn grass that seems impossible to eliminate from your garden beds, you’ve likely encountered quackgrass (Elymus repens). While some might mistake this perennial for a desirable native grass, quackgrass is actually a non-native species that has earned a reputation as one of the most persistent ...

Noxious plant alert!

This plant is listed as noxious where it's harmed public health, agriculture, recreation, wildlife, or property. While it may lend beauty to your garden, it can cause significant harm or damage. Its spread may be regulated or restricted in some areas. Expand for more details.

In Alaska Agropyron repens (L.) P. Beauv. - quackgrass

is listed as a

Prohibited weed.

In New Jersey Agropyron repens (L.) P. Beauv. - quackgrass

is listed as a

Prohibited (seed) weed.

Noxious weed classification

Class A:

Class B:

Class C:

Limited distribution. Eradication is required by law.

Limited in some areas, widespread in others. Mandatory control where not yet widespread.

Widespread. Control is often optional or managed at the local/county level.

Quarantined /Prohibited:

These are often Class A species that cannot be transported, bought, or sold.

Quackgrass: Why This Persistent Perennial Isn’t Welcome in Most Gardens

If you’ve ever battled a stubborn grass that seems impossible to eliminate from your garden beds, you’ve likely encountered quackgrass (Elymus repens). While some might mistake this perennial for a desirable native grass, quackgrass is actually a non-native species that has earned a reputation as one of the most persistent weeds in North American gardens and landscapes.

What Is Quackgrass?

Quackgrass is a perennial grass that belongs to the wheat family. This European and Asian native has established itself across virtually all of North America, from Alaska to Texas and from coast to coast. You might also encounter this plant under its numerous scientific synonyms, including Agropyron repens or Elytrigia repens, but regardless of the name, the challenges it presents remain the same.

Quackgrass has spread extensively across North America, establishing populations in all Canadian provinces and U.S. states. This widespread distribution tells the story of a highly adaptable species that thrives in diverse climates and conditions.

  • Species observed
  • No observations

Importantly, quackgrass carries noxious weed status in some regions. Alaska lists it as Prohibited, while New Mexico restricts its seed as Prohibited. These designations reflect the plant’s problematic nature and the difficulties associated with controlling its spread once established.

Why Gardeners Should Avoid Quackgrass

Despite its hardy nature and rapid growth, there are compelling reasons to avoid introducing quackgrass to your landscape:

  • Aggressive spreading: Quackgrass spreads rapidly through underground rhizomes, forming dense mats that crowd out desirable plants
  • Difficult to control: Its extensive root system makes complete removal extremely challenging
  • Allelopathic properties: The plant produces chemicals that can inhibit the growth of nearby plants
  • Limited aesthetic value: With inconspicuous yellow flowers and basic green foliage, it offers little ornamental appeal
  • Legal restrictions: Its noxious weed status in some areas makes cultivation inadvisable

Plant Characteristics

Quackgrass typically grows to about 2.6 feet tall with a rhizomatous growth form that allows it to spread horizontally underground. The plant produces narrow, medium-textured green leaves and small, inconspicuous yellow flowers during mid-spring. Its rapid growth rate and moderate lifespan contribute to its persistent nature in the landscape.

The plant shows remarkable adaptability to various soil types and growing conditions, thriving in both wetland and upland environments across different regions. This adaptability, combined with its rapid vegetative spread, explains its success as an introduced species.

Growing Conditions and Hardiness

Should you encounter quackgrass (whether intentionally or not), understanding its preferences can help with identification and management:

  • Soil: Adapts to coarse, medium, and fine-textured soils
  • pH tolerance: Thrives in soils ranging from 5.2 to 7.8
  • Moisture: Medium moisture requirements with low drought tolerance
  • Sun exposure: Shade intolerant, preferring full sun locations
  • Temperature: Extremely cold hardy, tolerating temperatures as low as -43°F
  • Hardiness zones: Hardy in USDA zones 3-9

Better Native Alternatives

Instead of quackgrass, consider these native grass alternatives that provide similar coverage without the invasive tendencies:

  • Buffalo grass (Bouteloua dactyloides): A native prairie grass perfect for low-maintenance lawns
  • Blue grama (Bouteloua gracilis): Drought-tolerant with attractive seed heads
  • Canada wildrye (Elymus canadensis): A native relative that supports local ecosystems
  • Little bluestem (Schizachyrium scoparium): Offers beautiful fall color and wildlife value

Management and Control

If you’re dealing with existing quackgrass populations, persistence is key to management. The plant’s extensive rhizome system requires repeated cultivation or targeted herbicide applications. Prevention remains the best strategy—avoid introducing soil or plant materials from areas where quackgrass is present.

The Bottom Line

While quackgrass demonstrates impressive hardiness and adaptability, these same traits make it unsuitable for most garden and landscape applications. Its aggressive spreading habit, limited ornamental value, and noxious weed status in some regions make it a plant to avoid rather than cultivate. When planning your landscape, choose native grass alternatives that provide similar benefits without the associated management challenges.

Your garden—and your neighbors—will thank you for making the more sustainable choice of native plants that support local ecosystems rather than disrupt them.

Elymus repens is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Elymus repens is also known as:

Agropyron repens | USDA symbol: AGRE2
Agropyron repens var. subulatum & | USDA symbol: AGRES
Elytrigia repens ex | USDA symbol: ELRE3
Elytrigia repens ex Nevski var. vaillantiana | USDA symbol: ELREV
Elytrigia vaillantiana | USDA symbol: ELVA3
Triticum repens | USDA symbol: TRRE9
Triticum vaillantianum Wulfen & | USDA symbol: TRVA4

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Monocot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Liliopsida - Monocotyledons
Subclass: Commelinidae
Order: Cyperales
Family: Poaceae Barnhart - Grass family
Genus: Elymus L. - wildrye

Species: Elymus repens (L.) Gould - quackgrass

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA