Glimpse from the Field:
what's up with our Stewardship Program?

Volunteers are welcome to join us at our Mission Blue Nursery or at any of our stewardship outings. Nursery activities vary depending on the season, but may include planting seeds, transplanting seedlings, washing pots, and processing seeds collected from the mountain. Stewardship Saturdays are every Saturday at various locations on the Mountain, South San Franicisco Weed Warriors are 2 days a month, and Cypress Lane Wetlands restoration is every Tuesday. You could be weeding or planting, depending on the season. Come join us!

Find out more about our Stewardship Volunteer Programs and the Mission Blue Nursery

Would you like to share your experiences on the Mountain? Our hands-on stewards will be making posts, but a Glimpse from the Field is not just about stewardship. We also want to hear from Mountain advocates - those of you who spend time on the Mountain and consider it to be a special place. Share that with us! Contact Alane if you're interested.


Broom Busting: yanking, sawing and nibbling...

Volunteers pull out French Broom seedlings above Buckeye Canyon (photo: Ariel Cherbowsky)

Stewardship Mountaineers have been busy busting broom above Buckeye Canyon. Over 1,500 Genista monspessulana shrubs and seedlings, a Mediterranean plant commonly known as French Broom, have felt the tug of our weed wrenches and the teeth of our saws over the past weeks.

French Broom
© Neal Kramer 2008
These troublesome invaders have been holding our focus as we await the showers and storms that moisten mountain soils and mark the beginning of our native planting season.

The rich native grasslands south of Buckeye Canyon have undergone extensive invasions by woody plants, including many native species like Toyon (Heteromeles arbutifolia), Coyote Brush (Baccharis pilularis), and Islay (Prunus ilicifolia)—apart from French Broom.

At the moment, however, French Broom has been our main target, and we’ve been ripping them off and cutting them out from patches of autumn’s golden prairies, thick with brittle bunchgrass tufts and lined with the dry outstretched seedheads of Common Yarrow (Achillea millefolium) and Douglas Iris (Iris douglasiana). French Broom shrubs that are too big to pull are cut and their bark peeled.

French Broom peeled stumpGrowing on the slopes just north of where we’ve been working are Silver Lupines (Lupinus albifrons) and California Violets (Viola pedunculata)—host plants of the endangered Mission Blue and Callippe Silverspot butterflies. Both plants would be devastated by broom. First-time teenage volunteers and seasoned volunteer veterans have both joined in the critical effort to challenge the grassy appetite of these relentless prairie consumers.

We’ve been satisfied to learn that the invasive woody shrubs are themselves food—and they don’t just feed our hunger for a hardy day of broom busting.

The University of California’s Statewide Integrated Pest Management Program found a broom gall mite in El Dorado County. To read more see Scotch Broom Gall Mite: A New Partner in Broom Management for California. Below is an excerpt from the article regarding the disruptive effects of the mite on broom shrubs.

The mites cause galls, small abnormal growths on the plant's buds, to form during feeding, greatly reducing Scotch broom's ability to grow and reproduce. This mite is considered to be an ideal biological control agent due to its specialized feeding habits and the debilitating damage it can cause to invasive weeds. In some areas, the gall mite has already killed large stands of broom.

However, the broom gall mite targets Scotch Broom (Cystisus scoparius), apparently not the French Broom we've been attacking ourselves.

Genista Broom Moth caterpillar defoliating French Broom
photo: Sutro Stewards
Yet we did notice a local creature that munches on French Broom. The Genista Broom Moth (Uresiphita reversalis) caterpillar was found scrunching its way along broom branches.

It is native to the United States and prefers plants like broom that form part of the pea family, Fabaceae. We are happy to have other species participating in the fight against broom on San Bruno Mountain.

Still, there is something worrisome about the Genista Broom Moth—our native lupines also form part of the pea family and thus the caterpillars may also target them!

The Sutro Stewards, for example, found the caterpillars eating their nursery stock of yellow Bush Lupines (Lupinus arboreus). See Genista Broom Moth - Friend or Foe? to read more about this surprising find.

Could the Genista Broom Moth defoliate the host plants of the Mission Blues, like the Silver Lupine (Lupinus albifrons)? It seems possible.

We’ll be keeping an eye on the lupines for signs of the Genista Broom Moth, especially in areas where French Broom grows near lupines—and now we have one more clear reason why we shouldn’t let French Broom encroach upon precious lupines!

    — Ariel Cherbowsky, Stewardship Coordinator for SBMW

Ariel recently joined Mountain Watch as our Stewardship Coordinator. He has thrown himself into this important work with great enthusiasm. If you're interested in joining Ariel in restoration and stewardhsip projects on the Mountain, contact him at


Native Gardens - words from our nursery volunteers

Chris's front yard "native island" this Fall - a Giant Buckwheat in the rear, with California Fuchsia in bloom (front left) plus several smaller buckwheats and grasses

Fall is planting time - so a few words of advice from two of our Mission Blue Nursery volunteers. California native plants are a wonderful addition to your garden - and functional too, since they are mostly drought-tolerant. In California, this is an important feature and one of the reasons natives are becoming more and more popular. If you live next to natural areas like San Bruno Mountain, you might consider replacing potentially invasive cultivars with local California natives. It's a good thing.

native Toyon laiden with berries; moisture-loving Juncus sp. (rush) under bird bathNursery volunteer Chris Read offered to share photos of her Burlingame native gardens this Fall. Chris got rid of her lawn about 6 years ago. She and her husband were motivated mainly by their interest in native plants, but their garden mixes both natives and non-natives. A well-designed mix will give you pleasure year-round.

In the Fall, your native garden won't be particulary flashy but beautiful just the same - natives will be at their peak in late Winter through Summer, and native Toyon will provide a bounty of berries for birds in the Fall.

California natives are usually dormant in the Summer, with many losing their leaves. But there are late bloomers like Coyote Brush, Goldenrod and California Fuchsia (top photo) which is a striking Summer/Fall bloomer. Chris's remaining non-natives continue to flower every year and also attract local birds and insects.

Islay (Hollyleaf Cherry) framed on the left by sagebrush and at the right rear by manzanitaWe'll revisit Chris's garden in the Spring when we'll see poppies, columbines, blue-eyed grass, Flannel Bush, Twinberry and a long list of others.

Chris's recommendation for someone beginning - just start the process with a few favorites to see what happens. Start a native plant "island" and then expand. Chris says it gets a little addictive and pretty soon you are adding more and more.

They love to hear that at the Mission Blue Nursery!

Freidel, left, at Mission Blue NurseryVolunteer Freidel Cohen shares plenty of good advice for the native gardener in her September 2015 article for the San Jose Mercury News - Pacifica. Freidel recommends choosing plants that are native to your specific area and that would grow naturally on nearby coastal bluffs, riparian habitats and hillsides - this will encourage locals bees, butterflies and birds to visit your garden! Plus the plants will be happy growing in their native conditions - that's a plus for you - less water, less pesticides and less work for you.

Our Mission Blue Nursery grows and sells plants that fit those requirements - they are from San Bruno Mountain and are adapted to growing conditons on the SF Peninsula - perfect for your local garden.

We hope to see you at our November Native Plant Sale at Mission Blue Nursery on Saturday November 7 - make your list now to load up on natives - you'll never have too many.


in spite of the drought...

Pacific Aster - Symphyotrichum chilenseEven with the yearslong drought, there is still plenty of life on the Mountain. The Mountain is so dry - it is almost painful to experience, but plants and animals do survive. There are late blooming wildflowers, some finding protected locations, but the lack of water has taken it toll. The very hardy Pacific Aster is not uncommon at this time of year and you will even find it baking in the sun along the Saddle Trail's edge. Think drought-tolerant California native - suitable for your garden!

I ventured up to the Saddle area with birding on my mind. Since it was already noon (I'll never make a serious birder since I'm not an early riser) I didn't hold out a lot of hope, but it was sunny and not windy. These were good signs - at least to see the usual supects. But it's Fall and there are birds migrating to their wintering grounds, and San Bruno Mountain hosts its share of travelers.

Golden-Crowned SparrowThe first Golden-Crowned Sparrows have arrived and can usually be seen hanging around with resident White-Crowned Sparrows, foraging on the ground - flying quickly to the scrub when they feel threatened. This one was "hiding" in a thicket of non-native blackberries. This plant is terribly invasive and difficult to control, but it provides food for both animals and humans. Check oublackberry "thief"t the blackberry picker - he's got a big bucket for blackberry pie, he says. I think it's illegal to collect in a State Park, but this species of blackberry is non-native and there's plenty for everyone, unfortunately.

It's a conumdrum, but non-native and invasive plants are sometimes attractive to birds, animals and insects and substitute for an absent native plant - providing nectar, berries and seeds.

NectarUmber Skipper on Bull Thistle and pollen feeding insects often use a variety of flowers in their diet. It's true that many insects, like butterflies, may have strict plant species requirements for laying eggs and providing food for larvae, but nectar for adults is a different thing. This Umber Skipper is feeding on the flower of the dreaded, invasive Bull Thistle. Birds, especially Goldfinch, love the thistle seeds and use the thistle "down" for nest building. Goldfinch have adapted to breed late in the season to take advantage of matured thistle.

Hermit Thrush - Winter visitorSo it wasn't a bad couple of hours up on the Mountain. In addition to just the joy of being outdoors I saw another new arrival for my bird list, a Hermit Thrush skulking in dense Arroyo Willows near Colma Creek. They arrive as early as September to the SF Peninsula. It's always exciting to see your first-of-the-season migrant.

I highly recommend a couple of hours on the Mountain - in spite of the drought.

    — Alane Gray, Mountain Watch Volunteer


Mountain Watch bids farewell to Iris...

hands full - as usualBidding farewell to an incredible naturalist, hard worker and a friend to many, was difficult. Iris Clearwater brought to Mountain Watch her extensive background in habitat restoration, native plant cultivation, invasive plant control, wildlife monitoring and her love of working with people. Her tenure here as our Stewardship Coordinator and Nursery Manager was WAY too short - as everyone will tell you who had the pleasure of working with her. Iris was most fulfilled when sharing her passion in a way that helped people see species and ecological processes around them in new ways. She's headed back East to be closer to her family.

Iris with Ted & Loretta, long-time volunteersThere was a great farewell BBQ in her honor at the Mission Blue Nursery before her recent departure. It seemed like everyone was there to say goodbye and wish her the best. Paul Bouscal manned the barbecue, serving up grilled treats brought by guests. To say the least, there was a lot of eating and good conversation.

Lou, nursery volunteer and keeper of its demonstration garden, had nothing but good things to say about Iris. "Iris's style, Lou with Ildiko, incoming nursery managerdemeanor, enthusiasm and overall joie de vivre were  contagious; she had us volunteers as well as our native plants dancing a merry tune. Her ability to bring in a variety of folks to work together on a project as well as her organizational skills are both exemplary... best of all, she's a hard worker herself!"

More glowing comments from stewardship volunteer Mary Beth also paint Iris as a wonderful leader. "Iris brought her energy and organization to us at a time when we sorely needed it. Her welcoming personal style and beautifully presented snack times increased our volunteer base so much that we may need more parking! She added some group socializing that turned out to be more fun than this particular introvert expected it to be and has made us a more cohesive group."

The parking area was certainly full at this farewell gathering - a tribute to Iris's contribution during her all-too-short stay with us at Mountian Watch. If you too would like to pay tribute to Iris and her contribution, please leave a comment below.


Mountain Watch Welcomes New Stewards...

Once Iris Clearwater, our Stewardship Coordinatior and Nursery Manager, announced that she would be leaving us, the hunt was on for her replacement - a seemingly impossible job. Her 1 year tenure was WAY too short, but her desire to be close to family back East sort of trumped everything. She will be missed. Her replacements will be 2 people - each working part time.

Ariel Cherbowsky will be the new Stewardship Coordinator. Ariel will be busy assessing prime restoration sites on the mountain - some old and some new. He will recruit and train volunteers and interns to work on stewardship restoration projects. There's a lot involved - plus he will work closely with the incoming nursery manager.

Ildiko Polony is our new Mission Blue Nursery Manager. The nursery has become a huge success and is an ongoing source of revenue for Mountain Watch - plus it's an important link to the native gardening community in the Bay Area and habitat restoration projects in the county. Managing the nursery is a big job - Ildiko will run the nursery with the help of volunteers and interns, with new volunteers always welcome.

Ariel Cherbowsky was born in Mexico City and grew up mainly in Encinitas, California, near the wonderful San Elijo Lagoon, a coastal estuary where he first tasted the fruitful work of habitat restoration. He continued to cultivate a passion for the diverse activities that encompass ecological restoration during his studies at UC Berkeley as a steward of Strawberry Creek and its watershed.

Ariel spent the last year helping lead restoration events in coastal San Mateo County at Mori Point, Milagra Ridge, and Rancho Corral de Tierra with the Golden Gate National Parks Conservancy.

He is passionate about historical ecology, the democratic promise of community-based restoration, bioregionalism, environmental art and poetry, and the magic of remnant ecosystems in a massively altered world.

Ariel is inspired by all who have been involved in San Bruno Mountain Watch, like many others working to protect nature in their backyard. He is deeply committed to improving the health of the Mountain and helping facilitate more loving connections between it and the communities that surround it.

Ildiko Polony has been a lifelong environmentalist. She mostly focused on advocacy for action on climate change - until she started gardening in her San Francisco backyard and discovered local wildlife. Asking herself the question, “how could I foster the birds, bees, butterflies, and surprisingly diverse wildlife I see,” the answer came in planting locally adapted California native plants. She quickly became a native plant fanatic, a habitat restoration gardener and knew the direction her life would now take.

A year later, she graduated from UC Berkeley with a degree in Conservation and Resource Studies, completing her thesis titled “Connecting People, Connecting Wildlife: A Bicycle Wildlife Corridor on Arguello Boulevard in San Francisco.” Since graduation she has worked at Larner Seeds, a California Native Plant Seed Company, worked as a backyard habitat landscaper and is currently a coordinator for Nature in the City’s Backyard Native Nursery Network. She is thrilled to join San Bruno Mountain Watch to help nurture native plants for restoration on the mountain and to work with all the talented and dedicated volunteers to continue the legacy of conservation and restoration.

Ildiko is also a professional modern dancer.

Stewardship of the Mountain is important - there are several opportunites to participate, both in the nursery and in the field. Check out all of our Stewardship Volunteer Programs - something for everyone!


seeds often need encouragement...

volunteers Freidel and AliciaThe nursery is hard at work getting seedlings ready for planting with the first rains - Fall is the big planting season for California natives which are mostly dormant during the warmer Summer months in the wild. Often the first step before sowing carefully collected seeds is some form of pretreatment which mimics conditions in nature that tell the seeds when to germinate.

Light, water, oxygen, and temperature are normally required for germination - and each species has different requirements based on their different adaptations for survival.

Scarification is any method of disrupting a hard seedcoat so that water and oxygen can enter and trigger germination. Faithful Mission Blue Nursery volunteers, Freidel and Alicia, are sanding lupine seeds to let moisture into the seeds' hard coating - something that can be naturally accomplished by fire.

   — Iris Clearwater, Stewardship Coordinator


It's a zoo out there!

All kinds of creatures visit the Mission Blue Nursery - not all welcome. But one of the delights of working at the nursery are surprise sightings of the Pacific Chorus frog, or Pacific Tree frog. They love the regular misting in the nursery and find dark, moist places to hang out most of the time. But when they perch on a Brownie Thistle leaf or pretend to be a hat decoration, they are always very lovable and adorable.

Frogs aren't the only creatures that seek out the coolness and water of the nursery. Birds are frequent visitors - we should probably start a list! But the other day I found another surprise visitor.

With a little help from my friend David Nelson, we believe the refuge seeker to be a Western Racer. It seemed to be drinking droplets of water from the leaves during a couple of weeks of extra hot and dry weather. It wound its way leisurely through the pots, inspecting the microcosm created by the weeds. Of course, it may have also been hoping to find some insects, or chorus frogs...

I was pretty thrilled to get to have a close look, and that it let me take photos to share with you!

   — Iris Clearwater, Stewardship Coordinator


Anise Swallowtail Season...

On Aug 6th, Dionne Dettmer, Doug Allshouse, and I discovered this wonderful example of Anise Swallowtail butterflies using a native host plant, Coast Angelica (Angelica hendersonii), which is sold at our Mission Blue Nursery. Anise Swallowtails hosts on plants in the Carrot Family (Apiaceae), and have adapted to the invasive Mediterranean fennel plant you see everywhere. Note that there were at least 10 on this one angelica plant.

How many can you find in just this photo?


And in different developmental stages called instars which can look different.

A week later, I was out there again, seed collecting and saw that they had gotten really big and plump. So cute, in fact, that I had to pet it, which it did not approve of, and let me know by surprising me with these bright orange antennae! I relented, and in order to resist petting them, moved on to collect seeds from the lovely CA Horkelia several paces away.

While stooping down, I was very surprised to see that one of these caterpillars had preceded me, and was hanging off of this stem, quite motionless. I wondered if it was getting ready to form a chrysalis?




About half an hour later, I decided to go back and check on it before leaving, and here's what I found! Notice how it has one strong string looped around its back to hold itself up, like a hammock. It was still wriggling around a little bit.




The following Saturday, I went back and found it like this, with a brightly colored underside. It will eventually emerge to look like this exquisite relative, who visited our nursery last month.

Apparently it goes from that hanging caterpillar stage to pupae in just 10 minutes! Had I only known. It takes at least 2-3 weeks, or more for it to emerge, so I'll keep checking, and see if I get lucky enough to see more.

Here is a nice webpage with an overview of its lifecycle, and if you have more time, I loved reading more about each stage - especially how it makes its sling, and emerges into a chrysalis.

   — Iris Clearwater, Stewardship Coordinator


Appreciating our interns!

Summer interns Dionne and AnnaMany thanks to our summer interns Dionne Dettmer and Anna Schlosser, who brought their dedication, positive attitudes, and hard work to every aspect of our work. Both helped out at our Wednesday nursery programs, helped to monitor the success of our plantings, collected seeds, washed pots, and helped in countless other ways - Dionne led the Tuesday Cypress Lane Wetland workdays, and Anna assisted our Saturday stewardship programs.

Also, a big thanks to Tara Kai Lam Centeio, who interned with us in the spring, and has continued to volunteer through the summer, and to Daniel Rodarte, whose photo we hope yet to Tara Kai and Dionne manning plant sale tablecatch. Daniel went on to an internship at Yosemite this past summer, and will be continuing his studies at SF State University. Tara Kai is going on to an AmeriCorps position at a community oriented farm in Pennsylvania, Anna is continuing her studies in Ecology at SF City College, and Dionne is finishing up her studies at College of the Atlantic, in Maine.

Thank you each. It has been a treasured gift to have your help and presence. We wish you the best, and we hope to continue to see you here throughout the coming years! You have made good friends here.

   — Iris Clearwater, Stewardship Coordinator


Welcome our new Stewardship Coordinator...

Iris Clearwater

Mountain Watch’s new Stewardship Coordinator has arrived! Iris Clearwater, a self-described “enthusiatic naturalist”, comes back to the Bay Area where she lived for 12 years — leading restoration work with Nature in the City, managing the native plant garden at Alemany Farm, searching for rare plants in the Golden Gate National Recreation Area (GGNRA), and leading restoration programs in the Presidio.

Iris will manage our Mission Blue Nursery and oversee our Stewardship Program, working closely with Joe Cannon our Stewardship Director. She brings with her extensive experience with invasive species control, vegetation research methods, herbarium work, and wildlife monitoring – as well as with community-engaged projects and the arts.

You can reach Iris at the Mountain Watch office at 467-6631, or by email at