Quackgrass
Agropyron repens
Last reviewed: June 2026
Light
part shade
Water
medium
Size
12"–48" H × 6"–24" W
Bloom
Jun, Jul, Aug, Sep
Native to
CO
Browse plants for this ecoregion
Quackgrass is an aggressive, spreading perennial grass that forms dense colonies through underground rhizomes. It produces upright seed heads from summer through early fall and can quickly dominate other plantings. This species is considered a noxious weed in many areas due to its invasive nature.
In an HOA neighborhood
Quackgrass takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.
- Spreads aggressively and invades neighboring properties
- Extremely difficult to control once established
Wildlife value
Provides some habitat and nesting material for small wildlife, though its aggressive growth often displaces more beneficial native plants that support diverse pollinators and wildlife.
Common questions
- How much sun does Quackgrass need?
- Quackgrass grows best in part shade conditions.
- When does Quackgrass bloom?
- Quackgrass blooms in June, July, August, and September.
- Where is Quackgrass native?
- Quackgrass (Agropyron repens) is native to CO, per the USDA PLANTS Database and regional native plant society lists.
- Is Quackgrass HOA-friendly?
- Quackgrass takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow Quackgrass? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
Not sure where to start? Take the 2-minute yard quiz