Common Name: European Beachgrass Scientific Name: Ammophila arenaria Code: AMAR4 Group: Monocot Family: Poaceae Growth Habit: Graminoid Duration: Perennial

What does it look like?

European beachgrass is a tough, perennial grass found on beach dunes. It has narrow (about 0.08-0.2 inches wide), rolled green leaves that turn brown in the fall, quite different from the broad, flat, blue-green leaves of native dune grass (BLM 2003).

American beachgrass is a native grass found in California that plays an important role as a dune stabilizer. This grass is a tall perennial, usually two to four feet, growing from long subsurface rhizomes, with long and narrow leaves. Its distinguishing traits are leaf clusters that surround an elongated flowering spike (LBJWC 2004). American beachgrass does grow in a few counties along the coast of California and in many cases is threatened by infestations of European beachgrass. It is vital to correctly identify these species and conduct removal projects targeting European beachgrass while promoting the growth of the native dunegrass species.

European Beachgrass

Where does it grow?

European beach grass is native to Europe and the eastern coasts of America, and was cultivated and spread for dune stabilization, basket-making and brooms.This species currently inhabits almost the entire coast of California.

While often in areas where dunes are stabilized, European beachgrass is most common on unstable dunes where there is continuous sand accumulation (Bossard, 2000).

Is it in our watershed?

There are no known areas of European beachgrass occurring on Mattole Beach. Previously, the Bureau of Land Management (BLM) manually eradicated threes sites in the King Range National Conservation Area (KRNCA) on the Lost Coast between Four mile Creek and the Cooskie Creek trail. These are the only “known” sites at this time and have been completely eradicated (pers. comm. Jennifer Wheeler). However, it is crucial to be vigilant for beachgrass in other areas and to report sightings immediately.

Why is it a problem?

This aggressive grass forms a dense mat of grass and rhizomes that dramatically alters native foredune habitats along the west coast. European beachgrass traps more sand than native beachgrass species, thus creating dunes with much steeper slopes. This change in dune morphology prevents the movement of sand from the beach to the interior dunes and disrupts conditions that support native plant communities.

European Beachgrass is also a primary threat to several endangered plant and animal species, such as the snowy plover, a marine bird whose nesting relies on areas of open sand or low, native dunemat vegetation. Beach Layia (Layia carnosa), Wolf’s evening primrose (Oenothera wolfii), and pink sand verbena (Abronia umbellata ddp.brevifolia) are sensitive or federally listed endangered species whose natural habitats are also threatened by European beach grass (NPS, 2001).

How do you get rid of it?

Manual Removal: For smaller sites, digging is one of the best ways to manually remove this plant. Begin by digging out the grass to the depth of the shovel blade. Cut the shallow rhizomes 6 inches below the surface to weaken the plant’s energy reserves. Remove resprouts every few weeks. It is possible to kill the grass within one season to a few years, depending on the site.

Mechanical control: Heavy machinery can remove large infestations of European beachgrass. At Oregon Dunes National Recreation Area, beachgrass was removed to a depth of 3.3 feet and then buried and covered up to one meter of sand. Moderate resprouting occurred the following spring, reinforcing the need to monitor removal sites closely (Pickart and Sawyer 1998 in Bossard 2000).

Author:
Unity Peterson, Invasive Plant Program Coordinator, Mattole Restoration Council, Petrolia, CA.

Photographs:
Saint Mary's College of California, 1995

References:
BLM. Noxious Weeds of the Arcata Field Office. Bureau of Land Management. http://www.ca.blm.gov//arcata/arcweeds.html

Bossard, CC., J.M. Randall and M. Hoshovsky. (eds.) 2000. Invasive Plants of California’s Wildlands. University of California Press, Berkeley, CA. Online version: http://groups.ucanr.org/ceppc/Invasive_Plants_of_California's_Wildlands

LBJWC 2004. Lady Bird Johnson Wildflower Center. Native Plant Information Network. http://www.wildflower2.org/NPIN/Plants/Detail.asp?Scientific_Name=Ammophila%20breviligulata

NPS 2001. Exotic Plant Species List. Scientific and Common Names of known Exotic Plant Species in the Redwood National and State Parks. National Park Service. http://www.nps.gov/redw/epsplist.htm