Pampas grass

Cortaderia jubata, Cortaderia selloana

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Background

Identification

Multiple plume-like collections of white flowers, each on stout stalk, often over 6 feet high (see photo).
Bunched mass of thin leaves, 1/2 in. wide and up to several feet long, with sharp finely serrated edges; haystack-like appearance.

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

Growth and spread

Spreads from wind-blown seed. Viable seeds, genetically identical to the parent, are produced without pollination.
Tiller fragments can sprout when soil is moist (Bossard 2000).

Habitat and local distribution

Native to South America, now found all over Bay and Delta region in disturbed sites and a broad variety of habitats. Has been used to control erosion in serpentine soils (Danielsen et al. 2003).

Impacts

Can form dense stands that exclude other plants.
Sharp leaves cut skin and can limit recreational use of area.
Dense colonies can be fire hazards.

Prevention and Control

Prevention

Plant natives or spread native seed in disturbed areas.

Manual or mechanical control

(DiTomaso 2000)

Hand removal of seedlings and established clumps—pickax or shovel effective tools; must remove entire crown and top-section of roots to prevent resprouting.
Prescribed burning—not an effective long-term control method due to resprouting.

Biological control

No known biological control agents (DiTomaso 2000).
Grazing by cattle successful in New Zealand (Harradine 1991; Gadgil et al. 1984).

Chemical control

Application of herbicides—spot treatment with post-emergence application of glyphosate; most effective when leaves sprayed to wet but not dripping (DiTomaso 2000).
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).

Integrated control

Remove top foliage by cutting or burning; treat regrowth with post-emergence herbicide (Harradine 1991).

References and more information

Danielsen, C. W., R. McClure, E. Leong, M. Kelley, and C. Rice. 2003. Vegetation Management Almanac for the East Bay Hills. Hills Emergency Forum, a consortium of eight local governments. Available from East Bay Regional Parks, Environmental Education Center, Tilden Park. (510) 528-6619.

DiTomaso, J.M. 2000. Cortaderia selloana. In Invasive Plants of California Wildlands. Carla C. Bossard, John M. Randall, Marc C. Hoshovsky, Editors. University of California Press. Available at http://groups.ucanr.org/ceppc/Invasive_Plants_of_California's_Wildlands .

Gadgil, R.L., A.L. Knowles, and J.A. Zabkiewicz. 1984. Pampas: a new forest weed problem. Proceedings of New Zealand Weed and Pest Control Conference. 37:187-90.

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.

Harradine, A.R. 1991. The impact of pampas grass as weeds in southern Australia . Plant Protection Quarterly. 6:111-15.

Element Stewardship Abstract for Cortaderia jubata, pampas grass . D.L. Peterson and M.J. Russo. 2002. The Nature Conservancy, Wildland Invasive Species Team. Arlington, VA. Available at http://tncweeds.ucdavis.edu/esadocs/cortjuba.html.

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