Life Has Returned to Hillside Trail

The South San Francisco Weed Warriors is an important arm of our Stewardship Program. Loretta and Chuck have led this group since 2011 and the results of their work to restore these important grasslands on the south slopes of the Mountain will be obvious when you visit - or when you come to volunteer! Check our Upcoming Events listings for dates of their monthly outings, or contact leaders Loretta and Chuck.

This "Glimpse From the Field" focuses on their work since the 2013 fire and highlights the group's achievements which were obvious in a February 2016 visit.

Loretta and Chuck will be showing off this area and leading a wildflower walk on these incredible and undiscovered south slopes on March 6th, 2016. See the Upcoming Events listings for complete details.


Fire is a constant threat to the Mountain. After a September 2013 fire that engulfed 41 acres, the south slope of San Bruno Mountain above South San Francisco looked bare and brown. This had been the stewardship area of our South San Francisco Weed Warriors, led by Loretta Brooks and Chuck Heimstadt. The Weed Warriors had already spent 2 years here, dedicated to pulling weeds to give a little extra help to struggling natives. Only a few coyotebrush escaped the fire, but on the upside many invasive plants – including non-native mustard, radish and Italian thistle were cleaned out - for the time being.

Because the Mountain is surrounded by urban areas, the danger to structures dictated fire control procedures. Fire trucks and bulldozers were called in to quell the flames and the long term consequences of drastic earth-moving strategies was uncertain to the SSF Weed Warriors. After the fire, park rangers supervised work crews to install erosion control before the rainy season. Then the Weed Warriors waited to see what would happen.

bulldozer tracks in 2013

bulldozer tracks in 2013

February 2016

February 2016

Despite the shortage of rain in 2014, good things began to happen and even with little or no rainfall plants began to re-emerge. The Hummingbird Sage sprouted, free of weeds and looking gorgeous. California Barberry, Coffee Berry, Coast Iris and Goldenrod all defied the relative lack of water and began re-growing. Then Checkerbloom, Lomatium and other natives appeared and flourished alongside the Silver Lupine (Lupinus albifrons var. collinus), one of the Mission Blue Butterfly’s host plants.

This provided an opportunity for the Weed Warriors to intensify their war on weeds. They first focused on removing non-native English Plantain (Plantago lanceolata) from around the re-growing lupine. The timing of the fire, at the end of summer after all the weeds had flowered and seeded, was ideal. Hopes were that many non-natives would be greatly reduced. Weeding areas were carefully selected to concentrate on the best habitat, based on plant diversity and plant rarity. So areas with Coast Iris, Coast Rock Cress and San Francisco Wallflower, and of course the Silver Lupine, were given special attention.

This approach of intensive weeding to give an advantage to existing native plants is still their method, with the goal of preserving what already exists. And they have been very successful.

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Silver Lupine & San Francisco Wallflower - 2016

Silver Lupine & San Francisco Wallflower - 2016

Coast Iris - 2016

Coast Iris - 2016

Hummingbird Sage - 2016

Hummingbird Sage - 2016

Over the last 2-1/2 years Loretta and Chuck have attracted a dedicated group of volunteers to help them with their mission. In addition to this great core group, they manage to attract botanists and naturalists eager to give a helping hand. Guests included Dan Gluesenkamp, Executive Director of the California Native Plant Society (CNPS); Jake Sigg, San Francisco botanist and Board Member for the Yerba-Buena Chapter of the CNPS; and Paul Heiple, botanist and naturalist, active in the Santa Clara Valley Chapter of CNPS.

Dan Gluesenkamp (in red)

Dan Gluesenkamp (in red)

Chuck and Jake Sigg

Chuck and Jake Sigg

Paul Heiple (left) and some of his Edgewood Weed Warriors

Paul Heiple (left) and some of his Edgewood Weed Warriors

When you visit this area, and you should, you will be overwhelmed by the diversity of the native plants thriving there and its beauty. All of the Weed Warriors' work has paid off. On a recent visit in February, with Spring starting to rev up, these plants were already in bloom and putting on a great show:

Silver Lupine - Lupinus albifrons var. collinus
Coast Iris - Iris longipetala
Hummingbird Sage - Salvia spathacea
California Poppy - Eschscholzia californica
Hillside Pea - Lathyrus vestitus var. vestitus
Caraway-leaved Lomatium - Lomatium caruifolium
Checkerbloom - Sidalcea malviflora
Wild Cucumber - Marah oregana
Common Yarrow - Achillea millefolium
Blue Dicks - Dichelostemma capitatum
San Francisco Wallflower - Erysimum franciscanum
Oregon Grape/ CA Barberry - Berberis pinnata
Milk Maids - Cardamine californica
Footsteps of Spring - Sanicula arctopoides
Shooting Stars - Primula hendersonii
Sticky Monkey Flower - Mimulus aurantiacus var. aurantiacus

And that’s just the beginning – soon other species with be joining in on the explosion of blooms - so don't miss it! Loretta and Chuck will be showing off this area and leading a wildflower walk on these incredible south slopes on March 6th, 2016. See the Event Listing for complete details.