Giant reed

Arundo donax

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  • Huge erect stems up to 30 feet tall, 1­1/2 in. thick, typically growing in clumps.
  • Smooth, arching, draping leaves, up to 3 feet long, 1/2 to 2 in. wide.
  • Plume-like collection of flowers at top of plant, cream to purplish.

Identification key in: Hickman, J. ed. 1993. The Jepson Manual: Higher Plants of California. University of California Press.

Growth and spread

  • Does not appear to produce viable seed; spreads with underground stems or by sprouting of plant fragments.
  • Can form extensive colonies.

Habitat and local distribution

  • Moist places, seeps, ditchbanks, freshwater to brackish.
  • Native to Europe or India, found on many Delta islands and adjacent mainland, downstream to Suisun Bay, some South Bay sloughs (Grossinger et al. 1998).


  • Displaces native plants and associated habitat through shading and groundwater reduction (Dudley 2000).
  • Large colonies are fire hazards.

Prevention and Control


  • Plant natives or spread native seed in disturbed areas.

General control notes

  • Follow-up monitoring and treatment required to remove resprouts (Dudley 2000).

Manual or mechanical control

(Dudley 2000)

  • Manual removal—combination of cutting stems and digging up roots with shovel or pickax.
  • Mechanical harvesting—reduces biomass but problematic since underground stems and roots must also be removed.
  • Estimated costs: harvesting costs range from $500-800 per acre, with additional costs for mobilization and equipment ($35,000-110,000) (WSDE 2001); there may be additional fees for disposal of plant material.
  • Prescribed burning—does not remove underground stems and roots and may cause damage to native species.

Biological control

  • Biological control agents—none have been approved by USDA for species (Dudley 2000).
  • Grazing (cattle, sheep, goats)partial success in reducing biomass of plant but does not eliminate underground stems and roots (Daar 1983).

Chemical control

  • Application of herbicides—glyphosate applied by foliar spray (most effective when applied after flowering and prior to dormancy period) or concentrated solution applied directly to freshly cut stems (TNC 1996).
  • Estimated costs: costs for materials and application by a contractor are approximately $250 per acre for glyphosate, depending on size of treatment area, scale of treatment, and herbicide dosage. It is recommended to contract a licensed professional for herbicide applications (Gibbons et al. 1999).

References and more information

Daar, S. 1983. Using goats for brush control. The IPM Practitioner. 5(4):4-6.

Dudley, T. 2000. Arundo donax. In Invasive Plants of California Wildlands. Carla C. Bossard, John M. Randall, Marc C. Hoshovsky, Editors. University of California Press. Available at's_Wildlands .

Gibbons, M.V., M.G. Rosenkranz, H.L. Gibbons, Jr., and M.D. Sytsma. 1999. Guide for Developing Integrated Aquatic Vegetation Management in Oregon. Center for Lakes and Reservoirs, Portland State University, Portland, OR.

Grossinger, R., J. Alexander, A. Cohen, and J. Collins. 1998. Introduced Tidal Marsh Plants in the San Francisco Estuary: Regional Distribution and Priorities for Control. San Francisco Estuary Institute, Oakland California.

TNC (The Nature Conservancy). 1996. Control and management of giant reed (Arundo donax) and salt cedar (Tamarix spp.) in waters of the United States and wetlands. Report by The Nature Conservancy, Southern Calif. Projects Office, to US Army Corps of Engineers, Los Angeles.

WSDE (Washington State Department of Ecology). 2001. Final Supplemental Environmental Impact Statement for Freshwater Aquatic Plant Management. Publication Number 00-10-040. Ecology and Management of Arundo Donax, and Approaches to Riparian Habitat Restoration in Southern California. G. Bell. 2002. The Nature Conservancy of New Mexico. Available at

Element Stewardship Abstract for Arundo donax, giant reed. M. Hoshovsky. 1986. The Nature Conservancy, Wildland Invasive Species Team. Arlington, VA. Available at .

Team Arundo Del Norte (web site) Contains a wealth of information on Arundo control.

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