Synonyms: Phalaris commutata, Phalaris stenoptera, Phalaris tuberosa
Common names: harding grass; bulbous canarygrass; phalaris; toowoomba grass
Phalaris aquatica (hardinggrass) is a perennial grass (family Poaceae) found throughout California. Hardinggrass is widespread in California because it has been used as a forage species and for revegetating after fires. It is most common in coastal valley and foothill grasslands from Oregon to the Mexican border. It is also found in the Sacramento and San Joaquin valleys at elevations below 4,000 feet (1,200 m). Hardinggrass is typically found along roadsides that are seldom mowed, allowing this tall, erect, leafy plant to dominate neighboring vegetation. In wildland habitats, hardinggrass can out-compete and displace native plant species. Tall stands of its dry foliage can present a fire hazard in summer.Cal-IPC Rating: Moderate?
CDFA Rating: None?
Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
Weed Management Notes
- Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.
Cal-IPC Newsletter Articles
- Prescribed grazing for invasive plant control on rangelands. Davy, Josh; Tate, Kenneth; Roche, Leslie. Vol 21, Issue 3
Cal-IPC Symposium Presentations
Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.
- Control of invasive plants after the Scorpion Fire on Santa Cruz Island. Woolsey, Jay; Parker, Mike; Carter, Katy; Little, Annie; Cowan, Clark (2022)
- Two years after the fire: accomplishments in invasive plant control following the 2018 Woolsey Fire. Algiers, Joey (2020)
- Weeds after Woolsey. Algiers, Joseph (2019)
- Controlling Harding grass (Phalaris aquatica) in a grassland setting _ an interim report. Samuels, Stassia; Julian, Laura S. (2012)
- Control of Phalaris aquatica on lowland coastal terrace prairie in Richmond, CA. Stafford, Monica; Farrell, Sharon; Beyer, Claire (2006)
- Grasses working group. Clines, Joanna; DiTomaso, Joe; Meyer, Tanya (2004)
- Out of the frying pan: Invasion of exotic perennial grasses in coastal prairies. Corbin, Jeffrey D.; Thomsen, Meredith; Alexander, Janice; D_Antonio, Carla M. (2004)
- Annual grasses: Status of biology and control. D'Antonio, Carla; Gerlach, John (2003)
Other Phalaris aquatica Information
- Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
- CalPhotos - Images of plants taken mostly in California.
- Calflora - Distribution map and records of this species in California.
- CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
- EDDMapS - Distribution of this species in North America.
- Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
- USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.