Beachgrass Removal, Orick Beach,
Redwood National and State Parks, California

by Jim Popenoe

Although we attacked European beachgrass in the Redwood National and State Parks early on, an entirely satisfactory eradication project eluded us until 1999. This time we copied a method used successfully at Lanphere Dunes under the leadership of Andrea Pickart. Beachgrass has an extensive system of rhizomes that enable it to outcompete other beach plants. These are the same rhizomes that bind sand into high dunes. The growth of rhizomes relies upon energy from above-ground photosynthesis in order to provide beachgrass its competitive advantage.

Pickart found that you can turn beachgrass' advantage on it head. Cut the beachgrass rhizomes well below the sand surface with a sharp shovel and remove the tops and attached sub-surface parts. This forces the rhizomes to send up new shoots without photosynthetic input, which depletes their energy reserve. Repeated cutting (the deeper the better) eventually kills the plants.

Detailed work records help us to evaluate the 1999 project. According to the 2001 exotic plant management annual report, 3270 person-hours were spent in 1999 to remove European beachgrass from Orick Beach (a.k.a. Freshwater Spit). Follow-up continued; 930 person-hours were spent in 2000 removing re-sprouts, and 150 person-hours were spent in 2001.

I retired from the Park Service in 2002, but I assume the number of person-hours continued to decline. However, monitoring and spot removals must continue indefinitely in order to control re-infestation. Winter storm waves detach beachgrass fragments from elsewhere and ocean currents disperse them along beaches.

Compared to eradication, a maintenance regime requires a relatively small annual investment of time. You periodically walk the beach looking for beachgrass and set bright flags to mark any that you find. If there is too much, you organize crews to help with the removal. You leave the flags in place until the beachgrass that you remove no longer has the energy to re-sprout.

If you want to learn more and to help personally eradicating beachgrass and thereby protecting the native dune-mat ecosystem, consider joining a scheduled European beachgrass bash in the park.