Weed Watchers - A volunteer-based invasive plant early detection program

Become a Citizen Scientist

Learn to identify invasive plants of the region and report your findings. 

Weed Watchers patrol the roads and trails of the national parks in San Mateo, San Francisco and Marin counties, detecting weeds as they first invade. 

Discovering weeds before they become well-established is critical to reducing damage to ecosystem integrity, preventing the loss of habitat for rare plants and animals, and preventing costly natural resource management. Deepen your understanding of the natural world while playing an important role in the protection of the unique resources at the park.

Getting Started


Download a set of "Plants Out of Place" ID cards or check out an illustrated plant list of priority invasive species

Join us on one of our hikes to help map and remove weeds. To sign up for a hike, check the survey schedule and contact the Weed Watcher Volunteer Coordinator to reserve a spot. 



Beginning Weed Watchers:

Use the What’s Invasive smartphone and/or internet reporting tool to learn about plant identification and document up to 14 invasive species in Golden Gate National Recreation Area or Point Reyes National Seashore.



Advanced Weed Watchers:

Use the SFNPS Weed Watchers user group on Calflora.org to report the location of any priority early detection species in the San Francisco Bay Area National Parks. You can use the online Calflora Observer tool or download the Observer app to record observations using a smartphone. For more information contact the Weed Watcher Volunteer Coordinator and I will add you to the list.




Contact Information

Weed Watchers Volunteer Program
Fort Cronkhite , Building 1063
Sausalito, CA 94965
Email: Eric_Wrubel@nps.gov
Phone: 415-289-1849