Weeds: Quackgrass – Elymus repens (Elytrigia repens, Agropyron repens)

categories: Pr-Sc Weeds

revision date: 2024-06-22 10:58

  • Family: Poaceae (Graminae)
  • Cycle: Perennial
  • Plant type: Grass
Ground level view of Quackgrass.
Photo by: D.G. Swan


Quackgrass is a perennial grass which spreads by both seeds and rhizomes, forming dense clumps if left unchecked. The spreading rhizomes are typically pale yellow in color and sharply pointed at the tips. Uncut plants are one to three feet high. The leaves are narrow and flat with rough upper surfaces. Leaf blades are frequently constricted near the tip, which helps in identifying non-flowering plants. The seed head of flowering plants consists of two rows of spikelets on opposite sides of the spike. The seed head is typically six to ten inches long. SPECIAL INFORMATION: Quackgrass can be difficult to eradicate once established. Repeated cultivation to expose and cut up the rhizomes has been effective in some areas. In Oregon, quackgrass is on the noxious weed quarantine list, which prohibits sale, purchase, and transport of plants, seeds, and plant parts.


Quackgrass is common in fields, grasslands, and waste areas on fertile soils. It may invade newly planted lawns, and also may become a problem in home gardens and ornamental plantings.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Digging and carefully removing all rhizomes will effectively eliminate single plants and small infestations.
  • However, this is very time consuming and frustrating.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Apply according to label directions.
  • Spot treatments with certain post-emergent herbicides will control weedy grasses, but will also kill the turf.
  • Glyphosate products should be applied as spot treatments only!
  • NOTE: Some ingredients listed here are only available in combination.
  • Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Landscape areas

  • dichlobenil
  • fluazifop
  • glyphosate

Turf areas

  • No products approved for use in turf.

Bare ground areas

  • dichlobenil
  • glyphosate

Additional Images