February 2021
A group of young Corps workers in their uniforms bag weeds under a sprawling tree
San Jose Conservation Corps crew members work on one of the Cape-ivy sites. Photo: Stephen Rosenthal
Partner Profile:
California Native Plant Society - Santa Clara Valley Chapter

The Santa Clara Valley Chapter of the California Native Plant Society (CNPS) organizes stewardship at numerous locations in municipal and regional parks. Their volunteer labor greatly expands the restoration workforce for these parks.

CNPS volunteers (and work crews, pictured) led by Stephen Rosenthal have been working since 2011 to restore the City of San Jose’s Alum Rock Park, the state’s oldest municipal park. They started in the overlook area at Inspiration Point, which features grassland with Ithuriel’s spear, fiesta flower, blue-eyed grass, soap lily, yarrow, and blue dicks, as well as a woodland with coast live, oak, valley oak, and blue oak. After a few years, they have significantly reduced the level of yellow starthistle (Centaurea solstitialis), Italian thistle (Carduus pycnocephalus), and milk thistle (Silybum marianum).

They next moved to “Fire Meadow”, where wildfire had recently opened the canopy. They planted 20 trees, including hollyleaf cherry, elderberry, and California buckeye within cages to protect them from deer browsing (trees donated by Central Coast Wilds). They also propagated hundreds of native plants from seed gathered in the park. On sites that are relatively inaccessible from roads, weeds like poison hemlock (Conium maculatum) and black mustard (Brassica nigra) are piled on site.

In 2020, Steve trained his sights on removing numerous Cape-ivy (Delairea odorata) infestations from Penitencia Creek, which flows out of Alum Rock Park and into Coyote Creek, emptying into the southern end of San Francisco Bay. By removing these incipient populations, volunteers are keeping the riparian weed from spreading further in the watershed.
Great talks online
The CNPS Santa Clara Valley Chapter maintains an excellent archive of video recordings on YouTube, including talks from Northern California Botanists’ conferences and CNPS Conservation conferences, as well as presentations on the chapter itself.
Close up of a series of bright yellow star burst shaped flowers in a nursery
Photo: CNPS - Santa Clara Valley Chapter
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Two volunteers in face masks hunch over the ground to pull weeds one stops to smile at the camera
Photo: Emily Repech
Find more Wildland Volunteer Network resources online
Looking for more ways to connect? Find resources on the Wildland Volunteer Network section of Cal-IPC's website:

  • Online map of Bay Area Volunteer projects
  • Organizations to volunteer with, sorted by county*
  • Archive of email newsletters with partner profiles

*You may need to check organizational websites to confirm if volunteer programs have restarted since 2020 shelter-in-place closures.
An Asian woman in a blue facemask black shirt and cap holds up a hori hori knife and large weed with carrotlike root
Photo: Kathleen Tarlow
The Wildland Volunteer Network helps strengthen volunteer connections in the Bay Area and beyond. Learn more about WVN.