Talking back to nativism

Dana Millbank is a political columnist for the Washington Post. He broke out of his political mold on April 7, 2023 to write an article about gardening published by the Post, which repeats every myth of the nativist ideology. 

A team of dismayed critics of invasion biology has responded to excerpts of Millbank’s column:

  • Marlene A. Condon is a garden writer based in Virginia and the author of The Nature Friendly Garden. She has a degree in physics. Her entire critique of Millbank’s column is available on her website.  Her comments address the reader.
  • Carol Reese is a retired Extension Horticulture Specialist who conducted her 27 year career from the University of Tennessee’s West Tennessee AgResearch and Education Center in Jackson, where a large and diverse display garden gave her the opportunity to observe biodiversity in action on an enormous range of plant species from other parts of the world. She describes herself as a farm raised country girl tomboy who has looked at the natural world in hundreds of settings and landscapes, natural and manmade, and read countless books and articles. She has written for several magazines, newspapers, articles for Garden Rant as well as university publications.  Her speaking engagements around the country have allowed her to engage with many other green industry professionals. Dana Millbank’s column prompted her to email him directly with her concerns, directly addressing some of his assertions. I publish some excerpts here from her emails sent directly to Millbank.
  • Conservation Sense and Nonsense is the webmaster of this website.  I have studied invasion biology and the native plant movement it spawned for over 25 years. I’ve watched forests of healthy, non-native trees in California be destroyed and replaced by weedy grassland.  I have used what I have learned to advocate for a less destructive approach to restoration, a word I am reluctant to use to describe projects that use herbicides to eradicate harmless plants and trees. My comments are addressed to the reader.

What follows are excerpts from Dana Millbank’s column with responses from Marlene Condon, Carol Reese, and Conservation Sense and Nonsense, just three of many skeptics of invasion biology.  To summarize the point of our criticism:

  • Insects are not dependent on native plants.  They are just as likely to use related non-native plants in the same genus or even plant family with similar chemical properties and nutritional value. 
  • While some non-native plants have potential to be harmful, many are beneficial. There are pros and cons to both native and non-native plants and that judgment varies from one animal species to another, including humans. For example, we don’t like mosquitoes, but they are important food for bats and birds.  
  • All plants, whether native or non-native convert carbon dioxide to oxygen and store carbon. Destroying them contributes to greenhouse gases causing climate change.
  • When the climate changes, vegetation must also change.  Many non-native plants are better adapted to current climate and environmental conditions in disturbed ecosystems.

Conservation Sense and Nonsense

“I’m no genius about genuses, but your garden is killing the Earth”
By Dana Millbank
Washington Post, April 7, 2023

Millbank:  I did almost everything wrong.

ReeseI’m so sorry you thought this!

Millbank:  For 20 years, I found the latest, greatest horticultural marvels at garden centers and planted them in my yard: sunny knock-out roses, encore azaleas, merlot redbud, summer snowflake viburnum, genie magnolia, firepower nandina.

In between them flowed my lush, deep-green lawn. I hauled sod directly from the farm and rolled it out in neat rows. I core-aerated, I conditioned, I thatched, I overseeded, I fertilized. I weeded by hand, protecting each prized blade of tall fescue from crabgrass and clover.

In this season, a symphony of color performs in my yard. The fading daffodils, cherry blossoms, saucer magnolias, hyacinths and camellias meet the arriving tulips, lilacs, creeping phlox and azaleas, with the promise of rhododendrons, peonies, hydrangeas, day lilies and roses to debut in the coming weeks.

But this year, the bloom is off the rose. And the hydrangea. And the rhododendron. And all the rest. It turns out I’ve been filling my yard with a mix of ecological junk food and horticultural terrorists.

Condon:  When Mr. Millbank posits that he’s “been filling his yard with a mix of ecological junk food and horticultural terrorists,” he’s channeling the kind of words Bringing Nature Home author Doug Tallamy loves to employ:  Biased expressions that implant negative images in the reader’s mind so he will become yet another minion of this scientist.  Nowadays you can’t read a garden or environmental column without being accosted with the same words or variations thereof, as if everyone has become a mouthpiece for Doug Tallamy, which I’ve never seen done more obviously than in this column by Dana Millbank. 

Conservation Sense and Nonsense:  Millbank’s lengthy list of “bad” plants in his garden paints with too broad a brush.  For example, instead of identifying a particular species of hydrangea and rhododendron, Millbank condemns an entire genus.  Both hydrangea and rhododendron genera have several native species within the genus.  Most (all?) species of phlox are also native to North America. 

Millbank:  When it comes to the world’s biodiversity crisis — as many as 1 million plant and animal species face near-term extinction because of habitat loss ― I am part of the problem. I’m sorry to say that if you have a typical urban or suburban landscape, your lawn and garden are also dooming the Earth.

Reese:  YIKES! This is pretty extreme, and dare I say inaccurate? No, home gardeners are part of the solution, no matter the plants in their garden. Doom will come from lack of diverse green space. Doom will come from climate warming as a result, as well as from pollution, tillage, factory farming and development.

Millbank:  I came to understand the magnitude of my offenses after enlisting in nature boot camp this spring. I’m in “basic training” with the state-sponsored Virginia Master Naturalist program. While others sleep in on rainy weekend mornings, my unit, the Arlington Regional Master Naturalists, has us plebes out in the wetlands distinguishing a yellow-bellied sap sucker from a pileated woodpecker.

I’m no genius with genuses, but I know a quercus from a kalmia, and because of my gardening experience, I began the program with confidence. Instead, I’ve discovered that all the backbreaking work I’ve done in my yard over the years has produced virtually nothing of ecological value — and some things that do actual harm.

A few of the shrubs I planted were invasive and known to escape into the wild. They crowd out native plants and threaten the entire ecosystem. Our local insects, which evolved to eat native plants, starve because they can’t eat the invasive plants or don’t recognize the invaders as food.

Anise swallowtail on non-native fennel. Courtesy “Papilio zelicaon, the anise swallowtail, typically has one to two generations in the mountains and foothills of California where it feeds on native apiaceous hosts. However, along the coast, in the San Francisco Bay Area and the urbanized south coastal plains and in the Central Valley, P. zelicaon feeds on introduced sweet fennel, Foeniculum vulgare, and produces four to six or more generations each year… the use of exotics has greatly extended the range of P. zelicaon in lowland California.” SD Graves and A Shapiro, “Exotics as host plants of the California butterfly fauna,” Biological Conservation, 2003

Reese:  It sounds so logical, but is sooo inaccurate. Ask any entomologist that has spent their careers “fighting pests” on valued crop or ornamental plants. Remember Pangea [when all continents were fused into one]? More recently, have you thought about the exchange of plants and animals across Berengia when we were still connected to Asia? We can trace those relationships/kinships of our plants to Asian/Eurasian plants now through DNA. They eventually differentiated into species (a continuum of change caused by climate and geologic pressures until we [Man] declare it as a different species, though biologically it is still basically the same nutritional makeup)

Condon also dissects Millbank’s statement: 

  • “They crowd out native plants and threaten the entire ecosystem.”  Read virtually any description of where you find so-called invasive plant species and you will find the word “disturbed.”  This tells you the soil profile has been negatively impacted by people, animals, or weather, and usually means the topsoil is gone.  Only very tough plants—known as colonizers—can grow in disturbed areas because the soil is nutrient-poor and is typically compacted.  Consequently, these areas may fill with a mix of native and nonnative plants, or mainly one or the other—but every single plant is a colonizer that is working to rehabilitate the land for the benefit of the native plants that require topsoil in which to grow.  “Invasiveness” is nothing more than a derogatory word used by people with contempt for alien-plant colonization.  Conclusions:  Alien plants can’t “crowd out” native plants because once the soil is disturbed and thus degraded, most of our native plants can’t grow there and thus are not there to be crowded out.  As for “threatening the entire ecosystem,” to the contrary, alien colonizers are helping to restore it.
  • “Our local insects, which evolved to eat native plants, starve because they can’t eat the invasive plants or don’t recognize the invaders as food.”  This oft-repeated distorted premise comes straight out of Bringing Nature Home, in which Doug Tallamy deceptively writes about “an excellent demonstration of how restricted a specialist’s [an insect with particular food preference] diet is.” Tallamy tells the story of Eastern Tent caterpillars on a cherry tee denuded of its own leaves but hosting a Japanese Honeysuckle vine.  He writes that the caterpillars didn’t recognize the honeysuckle as food (sound familiar?)  But, of course, they didn’t because this species of insect can only eat plants in the Rose Family, which does not include honeysuckle.  What Doug Tallamy doesn’t tell the reader is that the tent caterpillars could certainly have eaten the so-called invasive Multiflora Rose, which I’ve documented in the photo below.  Conclusion:  Native insects did not evolve to eat only local (native) plants, but rather can typically feed upon dozens, if not hundreds or thousands, of plants related to each other by family classification, even though they grow in other countries.
Tent caterpillar on multiflora rose.  Photo by Marlene Condon.

Millbank:  This in turn threatens our birds, amphibians, reptiles, rodents and others all the way up the food chain. Incredibly, nurseries still sell these nasties — without so much as a warning label.

Reese:  As I read, I also watch the many birds on my lawn, the fence lizards on my decks, the insects humming among the flowers in my diverse collection of native cultivars and introduced plants. 

Hummingbird in eucalyptus flower. Eucalyptus blooms from November to May. It is one of the few sources of nectar and pollen for birds and bees during the winter months when little else is blooming. Courtesy Melanie Hoffman
Eucalyptus leaf litter makes excellent camouflage for this garter snake. Courtesy Urban Wildness

Millbank:  Most of my other plants, including my beloved lawn, are ecological junk food.

Reese:  Now, now! Many (most) natives do not supply useful forage either. All plants supply some benefit. They provide shelter, create, improve and anchor soil, cleanse air and water, make oxygen and cool the planet. The plant must be judged on benefits versus detriments in each situation. If a nonnative plant is the only thing that will flourish in bombed out rubble, or contaminated soil, if it is providing many benefits, shall we rip it out because caterpillars won’t eat it? If we let it get established, will it ready the site for other species with more benefits to become established? Shall we get out of the way and let nature do what she does, which is heal herself?

Millbank:  The trees, shrubs and perennials are mostly “naturalized” plants from Asia or Europe or “cultivars,” human-made varieties of native plants bred to be extra showy or disease resistant but lacking genetic diversity or value to animals. I, like other gardeners I know, planted them after mistaking them for their native cousins. They’re not doing harm, but neither are they doing anything to arrest the spiral toward mass extinction.

Reese:  Please know that the most influential native plant botanical garden in the country (Mt. Cuba Center)  has trialed the cultivars of native plants for their ecological benefits and found as should be expected, that each cultivar must be judged on its own merits. Some are better than the straight native as in the coneflowers where ‘Fragrant Angel’ scored tops for pollinators and many others were very close to being as good as straight species. These cultivars were even better than the other species of Echinacea tested. BTW, I grow E. purpurea, pallida, paradoxa, tennesseensis and laevigata as well as many cultivars. Remember that cultivars should also be judged on not just nutritional value, but other factors that increase benefits, such as length of bloom period, numbers of blooms, drought resistance, heat tolerance, hardiness, ease of production (cost) and durability. Please ask to speak to Sam Hoadley there as he leads the research on beneficial cultivars and has completed and undertaken several studies of different native species. Great guy and great speaker. 

Please be aware that many cultivars originated as naturally occurring deviations in seedling populations, and as we know this actually diversifies the genetic pool, allowing Mother Nature to select the better form. We sometimes agree with her, and other times we may move along that diversifying form by crossing it with others that are demonstrating genetic variance. Logically, this actually furthers the cause of a broader genetic pool that can help in today’s crisis in showing which can cope and flourish.

Millbank:  To get a sense of my missteps, I asked Matt Bright, who runs the nonprofit Earth Sangha, a native-plant nursery in Fairfax County (and a lecturer on botany for my nature boot camp) to walk through my yard with me.

He took aim at my day lilies: “I would remove them all. Those have also become badly invasive.”

He spied my creeping jenny on a slope: “Another nasty invasive.”

He condemned to death my rose of Sharon shrubs (natural areas “have really been torn up by these guys”) and my innocuously named summer snowflake viburnum.

Worst was my row of nandinas — “heavenly bamboo” — along the foundation. “You definitely want to remove it,” he advised. Its cyanide-laced berries poison birds.

Condon:  This tactic is typical of the followers of Tallamy who want folks to perceive supposedly invasive plants as “bad” even though no evidence exists to support their accusations, especially in this instance.  Mr. Millbank and Mr. Bright, who obviously supplied this information, have misspoken here.  A study out of the University of North Carolina, Chapel Hill, published in 2022, explains that Cedar Waxwings are the only birds that might be poisoned, and that’s only going to happen if someone grows so many nandinas that these birds consume large numbers of fruits in a single feeding bout.  If you grow just one or even a few plants, you are not going to poison waxwings.

Conservation Sense and Nonsense:  Here in California, most berry-producing, non-native plants are considered “invasive” based on the assumption that birds eat the berries and spread the plants.  Nandina was briefly on the list of invasive plants in California until knowledgeable people informed the California Invasive Plant Council that birds don’t eat the toxic berries.  Nandina was removed from the invasive plant inventory long ago.

Bumblebee on Cotoneaster, Albany, CA. Cotoneaster is one of many berry-producing non-native plants on the list of invasive plants in California. Himalayan blackberries are another target for eradication in California. They are frequently sprayed with herbicide in public parks where children and other park visitors eat the blackberries.

I also have personal experience with nandina and cedar waxwings.  Flocks of waxwings visited my holly trees in San Francisco every year.  They did not touch my three nandina plants.

California buckeye (Aesculus californica) is an example of a native tree that is toxic.  Its flowers are toxic to honeybees and its big brown seeds for which it is named were used by Indigenous people to stun fish to make them easier to catch.  The bark, leaves, and fruits contain neurotoxic glycoside aesculin.  Every negative characteristic attributed to some non-native plant species is equally true of some native plant species.  No one mentions buckeye’s toxic characteristics because it’s a beautiful native tree.  Photo Sacramento Tree Foundation

Condon:   I’ve had a Rose of Sharon (Hibiscus syriacus) growing in my yard since I moved to my home in Virginia almost 40 years ago. In all this time, only one seedling from the plant I brought here has ever “volunteered” to become a second yard denizen.  During the past 37 years, pollinators have fed at the original plant and then also at its offspring. What I’ve found by experience in my yard is that few plants can successfully move into a space that’s already filled with other plants. (Proving what physics tells us–that no two physical objects can occupy the same space).  I’ve brought home numerous so-called invasive plants, only to have them disappear or simply stay put where I planted them. That’s because hundreds, if not thousands, of plants fill my yard. 

Conservation Sense and Nonsense:  Virginia is one of only four states in which rose of Sharon is considered invasive.  Condon’s experience with rose of Sharon in Virginia suggests that lists of “invasive plants” are either inaccurate or are serving another purpose (perhaps both).  The longer the list of “invasive plants” the more work is created for the “restoration” (AKA eradication) industry.

Rose of Sharon is not considered invasive in California. This is a reminder that the behavior of plants varies because of the wide range of climate and environmental conditions.  Nearly one third of the plants on California’s list of invasive plants are not considered invasive in California.  They are on the list because they are considered invasive in Hawaii, a state with a warmer, wetter climate than California.  In naming rose of Sharon as a dangerous invasive, a media resource with a national readership has made a generalization that red-lines more plants than necessary.  They become targets for eradication with herbicide and they deprive us of the biodiversity that is particularly important in a changing climate in which biodiversity ensures resiliency.

Millbank:  Bright did praise two “good” species I have that contribute to biodiversity: a sycamore and a catalpa as well as a “great” American elm and a “phenomenal” dogwood. (I couldn’t take much pride in them, though, because all four were here long before I arrived.) And Bright assured me I wasn’t a particularly egregious offender; my one-sixth acre lot in town is typical of the urban/suburban landscape.

●  ●  ●

Lawns, and those useless, ubiquitous cultivars of trees, shrubs and perennials sold by the major garden centers, are squelching the genetic variety nature needs to adapt to climate change.

Reese:  It’s actually the opposite. We need more plants in the mix. We need “the tumult of nature” to decide. We aren’t the jury, and we continue to interfere with our well-intended assumptions that we know best.

Lawns are full of wildlife when management is minimal. Mow. That’s all. Mow judiciously when “lawn weeds” are blooming. Watch birds feed on the many insects in the lawn including lepidopteran larvae. Realize that many moths pupate underground. Think of your lawn as haven for them and for the grubs birds relish as millions of acres across our country are being tilled for factory farms. Remember that the best habitat is mixed. Open areas bordered by wooded areas and most species love the borders. Our suburban landscapes are ideal if we just stop killing things.

This is a lawn that serves pollinators. Homestead Stencil Company

Millbank:  The resulting loss of native plants in our fragmented urban and suburban landscapes deprives both plants and wildlife of the contiguous habitats they need to breed and, over time, to migrate in response to climate change.

The deck is stacked against nature in this fight.

●  ●  ●

If possible, you should remove the nastiest of the invasive plants if you have them: burning bush, Japanese barberry, Asian bush honeysuckle, English ivy, callery (Bradford) pear and a few others.

But leave the rest of your plants alone, for now. Tallamy ultimately wants to cut lawn acreage in half, but “there is room for compromise,” he said. Think of your noninvasive plants and cultivars as “decorations.”

Janet Davis, who runs Hill House Farm & Nursery in Castleton, Va., has a similar message for the purists who make you feel bad about your blue hydrangea. “Don’t give me crap about something that’s not native but not invasive,” she said. “I’m never going to tell you you can’t have your grandmother’s peony.”

Thus absolved, I shed my guilt about my yard full of ecological empty calories. I kept my hydrangeas, azaleas and roses but pulled out the truly bad stuff. I dug up the nandinas and replaced them with native winterberry holly, red chokeberry and maple-leaf viburnum. I removed the rose of Sharon and substituted American hazelnut and witch hazel. I uprooted the invasive viburnum and planted a native arrowwood viburnum in its place.

I also took a small step in the painful task of killing my beloved lawn. I used landscape fabric to smother about 400 square feet of turf. In its place, I planted a smattering of canopy trees (two white and two northern red oaks), understory trees (ironwood, eastern redbud), shrubs (wild hydrangea, black haw viburnum) and various perennials and grasses (Virginia wild rye, blue-stemmed goldenrod, American alumroot, woodrush, spreading sedge).

My 38 plants cost $439 at Earth Sangha. But these natives, adapted to our soil and conditions, don’t require fertilizer, soil amendments or, eventually, much watering. Over time, I’ll save money on mulch and mowing.

Reese:  This one is so oft repeated and so very wrong. It depends on the plant, and it depends on the site. Plants in the wild require no input to succeed whether native or not because we have not messed up the soil and we have let the natural cycles of plant debris/decay improve the soil as it was meant to, creating a live, moist, interaction of microorganisms that work symbiotically to support the plant, which, btw has also been selected by nature for that site. It has absolutely nothing to do with origins. In fact, why would nonnative plants become “invasive” if they did not adapt as well or better than the native plants? I want to snort with laughter!

Millbank:  Right now, my seedlings look pretty sad. Where once there were healthy lawn and vibrant shrubs, there is now mud and scrawny sprigs poking from the ground every few feet. I put up chicken wire to keep the kids (and me) from trampling them. The carcasses of my invasive plants lie in a heap on the gravel.

Condon:  This statement supports my contention that ridding your yard (and, in the case of government, natural areas and parks) of “invasive” plants destroys habitat, leaving our wildlife high and dry.  Follow the advice of Doug Tallamy, via Dana Millbank (and many others) and you make the environment far less hospitable to our wildlife by removing plants that supplied habitat NOW when our critters need it to survive.

Conservation Sense and Nonsense:  This description of Millbank’s ravaged garden is consistent with my 25 years of observing native plant “restorations” on public land.  They all begin with destruction, usually accomplished with herbicides.  The first stage of these projects is often described as “scorched earth.”  Years later, there is rarely habitat comparable to what was destroyed.  Colored flags usually outnumber plants. 

This is what a native plant garden on Sunset Blvd in San Francisco looked like after two years of effort: more colored flags than plants. The sign claims it is “pollinator habitat.” Since when do pollinators eat flags?

Millbank:  But in a couple of seasons, if all goes well, my yard will be full of pollinators, birds and other visitors in need of an urban oasis. Years from now, those tender oak seedlings, now 6-inch twigs, will stretch as high as 100 feet, feeding and sheltering generations of wild animals struggling to survive climate change and habitat loss.

Conservation Sense and Nonsense:  Destroying harmless vegetation contributes to climate change by releasing carbon stored in the living vegetation and reducing the capacity to sequester more carbon.  Above-ground carbon storage is proportional to the biomass of the living vegetation.  Destroying large, mature plants and trees releases more greenhouse gases in the atmosphere than the young plants and trees can sequester.  Meanwhile, the climate continues to change and the native plants that Millbank prefers are less and less likely to be adapted to conditions.  Native plant ideology is a form of climate-change denial. 

A small forest of non-native trees was destroyed in a San Francisco park to create a native plant garden. Nine months later, this is what the project looked like: a tree graveyard.

Millbank:  I won’t be alive to see it. Yet even now, my infant oaks give me something the most stunning cherry blossom never could: a sense of hope.

Conservation Sense and Nonsense:  I feel bad for Dana Millbank.  He has been successfully guilt-tripped into believing he has damaged the environment.  He hasn’t, but destroying his harmless garden WILL damage the environment. 

We hope he will find his way back to a less gloomy outlook on nature, which will outlast us all in the end.  Altered perhaps, but always knowing best what it takes to survive.  The way back from the cliff he is standing on is through a study of evolutionary change through deep time to appreciate the dynamic resilience of nature, which may or may not include humans in the distant future.  Our message is “Embrace the change because change will enable survival.”

Suggested reading for those standing on the steep cliff created by nativism in the natural world:

Sunset Blvd: Biting off more than you can chew

Sunset Blvd is a major traffic artery that runs through the middle of the Sunset District, on the west side of San Francisco.  It is one of only three traffic arteries in the Sunset.  The Great Highway on the western edge of the Sunset, separates ocean beach from the dense residential neighborhood called the Sunset District.  The Great Highway is closed to traffic from Fridays at noon to Monday at 6 am for recreational purposes.   19th Avenue, on the eastern edge of the Sunset is State Highway 1, a major entrance into San Francisco from the south and north that is heavily congested around the clock. 

In other words, Sunset Blvd is vitally important to traffic traveling into and through San Francisco.  Yet, San Francisco’s “biodiversity coordinator” calls Sunset Blvd a wildlife corridor from Lake Merced to Golden Gate Park and he was instrumental in creating the Sunset Blvd Biodiversity Master Plan that is trying to transform Sunset Blvd into a 2-1/2 mile long densely planted garden.  The gardens are being funded by grants and non-profit organizations and planted by volunteers with no commitments for long-term maintenance.  The gardens are being watered by hand by the volunteers because the sprinkler system is no longer functional.  Faucets (quick couplers) were installed in each block as a substitute for the sprinkler system. 

Implementation of the Sunset Blvd Biodiversity Master Plan has been in progress for over 4 years.  This article is a progress report that is also a lack-of-progress report on a plan that seems to us misguided in some ways and too ambitious.  Sunset Blvd looks like a mess now, but it will be substantially worse when the short-term grants and volunteer commitments expire because the city does not have the resources to maintain it for the long-term.

Natural History of the Sunset District

This birds-eye view of San Francisco in 1868 (see below) shows why it’s challenging to garden in the Sunset District.  Most of the District was barren sand dunes.  The district is foggy during the summer and windy throughout the year.  There were few plants on the sand dunes and no trees.  Trees that are native to San Francisco do not tolerate salty ocean winds and sandy soil that doesn’t retain the moisture of our limited seasonal rain. 

Sunset Blvd was built in 1931, at a time when the Sunset District was barren sand.  It was planted with Monterey pines and cypress that are native less than 150 miles south of San Francisco, in a similar climate.  The trees were planted to provide a wind break for the residential neighborhood east of Sunset Blvd as well as to beautify a neighborhood that many consider bleak during the foggy days of summer. 

This (see below) is what Sunset Blvd looked like in the 1990s when I lived in the Sunset District:  A tall windbreak of Monterey cypress and pines with tall non-native shrubs below the canopy and mowed lawn on both sides of the windbreak, the sidewalk medians, and the center median.  It was a landscape that is easy to maintain because it can be mechanically mowed and irrigated with automatic sprinklers.  It was a simple, neat, and functional landscape.

The Sunset Blvd Biodiversity Master Plan

The windbreak on Sunset Blvd is dying of old age, which should be expected, given its age.  Reforestation should have begun decades ago in anticipation of the death of Monterey pines and cypress.  By 2019, many hazardous trees had been removed and 250 new trees were planted, with another 100 trees planned.  This year, intense winter storms have toppled many more trees on Sunset Blvd (and elsewhere), suggesting that all hazardous trees have not been removed. Public safety should be the top priority for any renovation project.  That doesn’t seem to be the case in this project.

Climate Action Network (CAN) obtained Cal Fire grants to plant trees and shrubs from Lawton to Pacheco.  They have planted a mix of both natives and non-natives and most are doing well after unusually heavy winter rains, 10 inches more than San Francisco’s average annual rain total of less than 23 inches. 

Lawton block of Sunset Blvd., January 2023

The master plan makes a commitment to create nine small native plant gardens done by several different organizations, including student organizations.  Department of Public Works—which is responsible for Sunset Blvd–has also given the entire block from Santiago to Taraval to the California Native Plant Society (CNPS) to garden with exclusively native plants. The Memorandum of Understanding (MOU) with CNPS also gave them the block from Kirkham to Lawton to plant a wildflower meadow.  The meadow CNPS planted there failed and that part of their plan has been abandoned.  The MOU with CNPS obligates them to provide the plants, irrigate, and maintain the garden for three years.  Many dead tree saplings in that block suggest watering may be haphazard. CNPS has made the most effort at the corner of Taraval and Sunset Blvd.  These three photos (below) show what this small native plant garden looks like at different times of the year. 

Taraval and Sunset Blvd, spring 2022. CNPS photo
Taraval and Sunset Blvd, October 2022
Taraval and Sunset Blvd, January 2023

The center median of Sunset Blvd that was mowed and irrigated grass in the past was planted with a mix of native and non-native drought tolerant plants several years ago.  After several years of intense drought and no available irrigation, only the succulents survived, leaving bare ground populated by weeds that can’t be mowed because of the succulents.  The weeds are sprayed with herbicide by Department of Public Works.  In 2021, the center median was sprayed 38 times with 238 gallons of herbicide. Thankfully, the wide medians between the boulevard and side streets are not being sprayed with herbicide. In 2021 and 2022, over 20% of all herbicide spraying by DPW was done on the center median of Sunset Blvd. 

The Public Utilities Commission has created 151 rain gardens in San Francisco and about 30 of them are on Sunset Blvd.  PUC is using both native and non-native plants, but they are under intense pressure from native plant advocates to plant exclusively natives. The rain gardens aren’t irrigated, so they look pretty shabby during dry summer months. Although they reduce run off into the sewer system, some members of the public are likely to judge them by what they look like. PUC is trying to recruit neighbors to take care of them.  The Sunset Blvd Biodiversity Master Plan leans heavily on the public to take care of Sunset Blvd.

Rain garden on Sunset Blvd, August 2022

What do Sunset residents want?

Is the Department of Public Works (DPW) giving residents what they want on Sunset Blvd?  The do-it-yourself playgrounds and seating areas created by neighbors may be a better indication of the preferences of Sunset residents.  This DIY playground (see below) has provided seating, a play structure, a basketball hoop, and a horseshoe throw.  On a sunny Sunday morning in January 2023, the adults were supervising their children in their homemade playground.  A mowed lawn would provide space for such recreational activities.

Homemade playground on Sunset Blvd, January 2023

There are also DIY gardens with seating that have been created by neighbors.  In this case (see below), non-native succulents have been planted in some of the many logs of dead trees on Sunset Blvd.

Homemade garden on Sunset Blvd., January 2023

San Francisco city officials had something different in mind.  The design goals of the Sunset Blvd Biodiversity Master Plan were:

Create Meaningful Public Spaces:
– Create areas of passive and active recreation that build on neighborhood cultural resources
– Design an immersive trail experience that connects to citywide trail network
– Engage the community through outreach initiatives for planting, maintenance, and education
Cultivate a Biodiverse Landscape:
– Support San Francisco Biodiversity Resolution
– Plant native species that provide critical wildlife habitat with a focus on insects, pollinators, and birds
– Develop educational opportunities to learn about local biodiversity and wildlife
Provide Ecosystem Services:
– Manage stormwater with green infrastructure to support PUC initiatives
– Minimize water use with drought tolerant plants
– Sequester carbon by increasing plant diversity [Carbon storage is not related to plant diversity.]

This is what city officials have actually delivered on Sunset Blvd:

  • A complex landscape that must be watered by hand by volunteers. 
  • A landscape that can’t be mowed because it has been intensively planted with plants.
  • A landscape that is dominated by weeds, except in the center median, which is sprayed with herbicide.
  • Although some old trees have been removed, many aging, hazardous trees remain.  Many new trees will not be tall trees that provide a windbreak. Many new trees are dead because hand watering by volunteers is haphazard.
  • A landscape that looks messy now, but will look substantially worse when grant funding and volunteer commitments expire. 
  • A complex landscape that requires labor-intensive maintenance and can’t be maintained by the city in the long term.


The Sunset Blvd Biodiversity Master Plan is too ambitious.  It is trying to create a complex landscape that can’t be maintained without volunteer labor because the city doesn’t have the resources to maintain it.  The main goal for Sunset Blvd should be a landscape that reflects the preferences of the residents of the Sunset District, rather than the wishes of city bureaucrats. 

Assuming Sunset residents would like a safe windbreak, more hazardous trees must be removed.  Many are clearly dead and are obvious candidates for removal.  Replacement trees must be tall enough to provide a windbreak and they must be capable of tolerating salty ocean winds.  New trees must be watered weekly during the dry season for at least three years.  An irrigation system is required because hand watering is not reliable enough to ensure survival of new trees.

San Francisco’s General Plan (see policy 4.1) defines “biodiversity” as including both natives and non-natives.  A diverse landscape of natives and non-natives is more resilient because each has a different tolerance for changes in climate and environmental conditions.  A diverse garden also prolongs the blooming period, which serves pollinators best.  We visited the UC Berkeley Botanical Garden in early April to see a stunning display of blooming plants in the South African section of the garden.  On the same day, little was blooming in the California section of the garden. 

South African Collection, UC Berkeley Botanical Garden, April 8, 2023
North Coast, California Collection, UC Berkeley Botanical Garden, April 8, 2023

If new plantings were confined to the center of the wide medians, weeds could be mowed to serve as an ersatz lawn.  I walk in a local cemetery every day.  The “lawn” is 90% weeds.  It was dominated by oxalis from January to April.  Now purple alfalfa, clover, and English daisies are blooming.  The weeds are mowed and become a part of the lawn.  No one looks closely to distinguish weeds from grass.  The weedy lawn is rarely irrigated and is brown during most of the dry season.  It is now lush green after winter rains.  This is a sign (below) in one of our cemeteries that begs indulgence of visitors for this responsible response to the drought. 

St. Mary’s Cemetery, Oakland, California, January 17, 2023

There are several advantages to a weedy lawn.  It creates recreational space that can be used by residents in any way they choose, e.g., picnicking, playing ball or Frisbee, sunbathing, etc.  It does not require more water than the intensive planting on Sunset Blvd that is now watered by hand.  A weedy lawn provides flowering weeds that are useful to pollinators.  Most of all, it is a landscape that does not require labor intensive maintenance that the city cannot afford. 

The Sunset Blvd Biodiversity Master Plan is an example of short-term thinking that has not given enough thought to the long-term consequences of the choices it has made.  Residents of the Sunset District are living with the consequences of the short-term thinking that is typical of most public land management. 

A Necessary Nuisance: The Undervalued Functions of Non-native Aquatic Plants

Julian Burgoff

I am grateful to to Julian Burgoff for giving Conservation Sense and Nonsense this opportunity to publish his guest article that adds to our extensive collection of articles about the benefits of non-native plants and the damage done by herbicides to needlessly destroy them. Julian Burgoff is an avid bass angler and aspiring fisheries ecologist from western Massachusetts. He is currently a master’s student with the Massachusetts Cooperative Fish and Wildlife Research Unit at UMass- Amherst where he studies juvenile river herring age, growth and habitat use in coastal Massachusetts lakes and estuaries. He is passionate about lake ecology and the management of aquatic vegetation in lakes and hopes to work in a field related to lake conservation and warmwater fisheries management in the future.

Conservation Sense and Nonsense

Natural resource managers and scientists in the United States often use divisive, warlike language when referring to both terrestrial and aquatic plants they consider to be “invasive” species, devolving the complexity of ecological interactions into good vs evil rhetoric. Like terminology used by the US government to define groups such as undocumented immigrants, nonnative “invasive” species are often referred to by natural resource managers and scientists in this country as “alien” and “exotic,” causing “nuisance infestations” and economic and ecological “harm.” This demonization of non-native species is illustrated by the title of a seminar conducted last spring by the State of Connecticut’s Agricultural Experiment Station Invasive Aquatic Plant Program regarding the relatively recent proliferation of Hydrilla Verticillata in the lower Connecticut River:

Despite the hyper-negative perception cast upon non-native species, the reality is that non-native organisms often provide important ecosystem services in highly altered landscapes and waterbodies that are often completely overlooked and highly undervalued by the scientific community.

Aquatic plants harbor an immense amount of aquatic life in lakes, ponds, and rivers. They stabilize lake and river bottoms, sequester/cycle nutrients, provide oxygen, improve water clarity, and serve as important habitats for all aquatic life from small macroinvertebrates (larval insects) and zooplankton (free-floating microorganisms) to large predatory fishes. The aquatic plant communities in lakes and rivers of the United States are subject to sustained stress via anthropogenic disturbances to land and water. Land use changes including corporate agriculture, development and expansion of impervious surfaces, wastewater pollution and damming of rivers have all contributed to dramatic changes in aquatic ecosystems and their aquatic plant communities since the colonial invasion of the North American continent.

Non-native aquatic plants have long been blamed for their supposed negative ecological impacts to lake and river ecosystems. As a response to eutrophication (i.e. nitrogen and phosphorous enrichment from human activities), non-native aquatic plants can grow in extremely dense stands that are perceived to outcompete native aquatic vegetation, decrease water quality (e.g. lower dissolved oxygen), and reduce foraging efficiency for predatory fish. While this may be accurate at various spatial/temporal scales, the prolific growth of non-native aquatic plants also serves a multitude of benefits for lake and river ecosystems and the organisms that they support.

Non-native aquatic plants have a tremendous capacity to improve water quality in freshwater ecosystems. In tropical climates like Florida, floating plants such as Hyacinth (Eichhornia crassipes) and Water Lettuce (Pistia stratiotes) sequester nutrients from the water and produce allelochemicals (chemical compounds released by plants) that, along with physically shading areas of the water, can reduce harmful algal blooms.

Photo: Kevin Copple
Cyanobacteria bloom on Lake Hatchineha, Kissimmee, Florida

 In the northeast, Water Chestnuts (Trapa natans) provide similar ecosystem services in terms of shading, nutrient cycling, and competition with algal taxa. Non-native submerged aquatic plants such as Eurasian Milfoil (Myriophyllum spicatum) and Fanwort (Cabomba caroliniana) also compete with algae and cyanobacteria via allelopathy and physically collect suspended sediment and algae particles from the water column, improving water clarity.

Photo: Jody White
Eurasian Milfoil in a tidal tributary of the Potomac River
Dense Eurasian Milfoil in an urban central Massachusetts lake
Dense stands of Fanwort with holes/edges of clear water in an otherwise turbid, hyper-eutrophic Central Massachusetts lake

All of these plants provide habitat for a diverse array of macroinvertebrates and zooplankton, and thus contribute essential prey resources to feed the higher organisms up the food web like fishes.

Depiction of the interactions between plants, macroinvertebrates, zooplankton and fishes underneath beds of water chestnut on the Hudson River

Not all fisheries and aquatic ecologists are blind to the ecosystem services provided by non-native aquatic plants. Researchers following the recovery of submerged aquatic vegetation on the Potomac River and Upper Chesapeake Bay since the 1980s have documented the important role that hydrilla played in reestablishing water clarity and facilitating the regrowth of native aquatic plants such as Eel grass (Vallisneria americana) and Coontail (Ceratophyllum demersum). Long-term assessments of aquatic plant communities in these ecosystems failed to reveal the catastrophic impacts to native flora and fauna biodiversity claimed by the Connecticut Invasive Aquatic Plant Program. Similarly, a study regarding the impacts of hydrilla on the biodiversity of plants, fish and waterfowl in 39 Florida lakes conducted on multiple time scales found no significant effects on metrics of ecological health. A quote from the abstract of this article depicts the main findings:

“Our conclusions support the hypothesis that hydrilla in these Florida lakes has occupied a mostly vacant ecological niche and has not affected the occurrence or relative composition of native species of aquatic plants, birds, and fish.”

“Lack of exotic hydrilla infestation effects on plant, fish and aquatic bird community measures,” Mark Hoyer, et. al.

There seems to be a common pattern with aquatic plant “invasions”. Water quality suffers due to human activities which affect the ability for native plants to grow, opening a niche for more tolerant species to proliferate and this in turn often remediates conditions enough to allow native taxa to reestablish. Where native aquatic plant communities remain intact and water quality remains high, the degree to which “invasion” of non-native aquatic plants occurs is often buffered by the integrity of the existing native plant communities. The notion that non-native aquatic plants enter an ecosystem and completely overtake the native plant community is rarely, if ever, an actual phenomenon realized in nature. In my view, the trouble comes when humans seek to selectively intervene with species interactions and try to control aquatic plant communities with quick fixes like herbicides and algicides as band-aids to cover up the consequences of poor water quality. These “management” efforts often result in a net loss of ecosystem services, biodiversity, habitat, and water quality.  The pictures below illustrate this phenomenon.

Variable-leaf Milfoil (Myriophyllum heterophyllum) growing amongst native Yellow Water-lily (Nuphar lutea) in an eastern Massachusetts lake
Variable Milfoil left to rot after a chemical herbicide treatment in a neighboring eastern Massachusetts lake

Where I live in Massachusetts there are dozens of small ponds and lakes that are sprayed with herbicides annually to treat “nuisance” aquatic vegetation. Most aquatic plant “control” here is driven by the desires of lakefront property owners who are concerned with their property values and want to transform the lakes they live on into swimming pools (full of toxic cyanobacteria, I suppose). A select few private lake management companies (e.g., Solitude Lake Management) enjoy a monopoly over the lake management market in this region and are endorsed by herbicide manufacturers to put chemicals into our water in the name of ecological “restoration”. Unfortunately, there is often extremely limited pre and post water quality monitoring, and almost never in-depth pre and post monitoring for impacts to indicators of biotic health (native plant communities, zooplankton/macroinvertebrate communities, fish etc.) following these treatments.

 While this issue is not studied nearly enough by independent scientists (i.e. those not representing institutions funded by chemical manufacturers), numerous studies have shown that lake herbicide treatments can have negative impacts to water quality, native plant communities, zooplankton communities, fish and wildlife. I have witnessed firsthand the negative consequences of herbicide use to “control” non-native aquatic plants ever since I was a kid. I’ve seen numerous lakes with abundant milfoil populations turn from crystal clear water to pea soup, with dense cyanobacteria blooms following chemical treatment.

Some of the healthiest lakes are those which have never been subjected to large-scale herbicide treatments. One such lake, Lake Bomoseen, is one of the most important fisheries in the state of Vermont, offering trophy Brown Trout, Largemouth Bass and Smallmouth Bass angling opportunities. Since the 1980s, the lake has supported an abundant population of Eurasian Milfoil. An excellent example of the ecosystem services achieved by allowing species interactions to occur unmolested over time, Lake Bomoseen supports an extremely healthy native aquatic plant community in addition to the dense stands of Eurasian Milfoil present around the lake. In 2022, the Lake Bomoseen Association, comprised of select individuals who own property around the lake, requested a permit from the Vermont Department of Environmental Conservation for the use of an herbicide ProcellaCOR to treat the entire littoral zone (i.e. the area of the lake where plants grow) of the lake over a 3-year period. This spurred a tremendous amount of public dissent. Lakefront property owners, local anglers, and hundreds of Vermont citizens concerned with the use of chemicals in the lake have united and made their voices heard on the issue. The Vermont Fish and Wildlife Department submitted a review of the treatment application to the Vermont DEC, stating that the proposed treatment was a threat to the health of the lake and the integrity of its fish populations. An excerpt from the review sums up the position of the VT Fish and Wildlife on this proposed treatment:

“Lake Bomoseen supports high-quality sportfish fisheries that rely on a diverse healthy aquatic plant community, which may be harmed by wide-scale application of pesticide, thus impacting these sportfish populations and the public benefits they support. The pesticide application at the scale proposed presents a risk to fishing as a public benefit.”

Vermont Fish and Wildlife

The proposal is still under review by the VT DEC, which if approved, would be the largest lake-wide herbicide treatment ever conducted in the state of Vermont. More information about this issue and how you can support the folks fighting to stop this treatment can be found here.

My observations of aquatic plant communities and their importance as habitat for fish have led me to pursue a career in fisheries and aquatic ecology. Before I had ever read a single piece of scientific literature, I had internalized many of the complex interactions between fish and aquatic plants based off of intuition derived from thousands of hours of on the water experience fishing in eutrophic, heavily vegetated Massachusetts ponds and lakes. To this day I am obsessed with fishing in thick aquatic vegetation. In the summer months on a hot sunny day I will actively seek out lakes with the densest aquatic plants I can find to chase after big bass hiding in the matted cover. I share this passion with thousands of anglers across the country.

Native aquatic plants can grow in dense stands, too. This is a cavernous mat of Elodea canadensis over +/- 9ft of water in a bay on southern Lake Champlain
Releasing a Largemouth Bass extracted from the canopy pictured above

Next time you go to your local lake or river, spend some time looking at the aquatic plants that inhabit that body of water. If you have the opportunity, go under the water to observe how fish utilize and interact with stands of aquatic plants. Notice all the life that resides within the plants and try to appreciate the organisms that you encounter, regardless of where in the world they may have originated.

Julian Burgoff
Amherst, MA

California’s “Sustainable Pest Management Roadmap” is a 25-year poisonous pathway

California’s Department of Pesticide Regulation (DPR) has published a draft of a policy that would replace its Integrated Pest Management policy with a Sustainable Pest Management (SPM) policy that is different in name only.  SPM makes a commitment to continue using pesticides in California until 2050, and by implication, beyond.  It makes NO commitment to reduce pesticide use or reconsider the current targets of pesticide applications.  It claims that the health hazards and damage to the environment will be reduced by identifying “Priority Pesticides” for possible substitution or “eventual elimination.”  It doesn’t commit to identifying any specific number of dangerous pesticides nor does it provide specific criteria for selecting these dangerous products.  It claims that increased testing and development of new products will result in safer products and puts these judgments into the hands of “stakeholders” with “experiential and observational knowledge” rather than scientists with expertise in soil science, endocrinology, toxicology, epidemiology, biology, botany, horticulture, etc.  The “stakeholder” committee that wrote the SPM proposal for urban areas included the manufacturer of pesticides and other users and promoters of pesticides. 

That’s not an exhaustive list of the many faults of SPM and the dangers that lurk in it.  I hope you will read it yourself and consider writing your own public comment by the deadline on Monday, March 13, 2023, at 5 pm.  The document is available HERE.  It’s less than 100 pages long and it is a quick read because it is basically a collection of bullet-points.

This is how to comment:  “DPR is accepting public comments to inform the prioritization and implementation of the Roadmap’s recommendations through March 13, 2023 at 5 p.m. Comments can be shared in writing to or by mail to the department at 1001 I Street, P.O. Box 4015, Sacramento, CA 95812-4015.” Please note that Department of Pesticide Regulations is not offering revisions, only “prioritization and implementation.” 

My public comment on California’s “Sustainable Pest Management Roadmap”

 A summary of my public comment is below.  A link to the entire comment is provided at the end of the summary:

Public Comment on
“Sustainable Pest Management Roadmap”
(AKA “Pathway to poisoning the environment for another 25 years”)

My public comment is focused on pesticide use in urban areas because of my personal experience and knowledge of pesticide use where I live.  These are the broad topics I will cover in detail with specific examples later in my comment:

  • Since glyphosate was classified as a probable carcinogen by the World Health Organization in 2015 and the manufacturer of glyphosate settled 100,000 product liability lawsuits by awarding $11 billion to those who were harmed by glyphosate, public land managers have been engaged in the process of substituting other, usually equally or more dangerous herbicides for glyphosate to deflect the public’s concerns.  The Sustainable Pest Management Roadmap (SPM) formalizes this process of substitution without addressing the fundamental problems caused by pesticides. 
  • SPM endorses the status quo that exists now.  Affixing the word “Accelerating” to SPM is an extreme case of double-speak that deliberately obscures, disguises, distorts, or reverses the meaning of words.  SPM ensures that toxic pesticides will be used in California for more than 25 years, to 2050, and likely beyond.  SPM therefore accelerates the damage to the environment that is occurring now.  Given that climate change will enable the movement of more pests into areas where they are now suppressed by weather, greater use of pesticides should be anticipated so long as the underlying issue is not addressed.
  • The underlying issue is that pests have been identified for eradication that in some cases cannot be eradicated and in other cases should not have been identified as pests either because they are innocuous or because of the valuable ecological functions they perform.  The key question that SPM does not address is whether pesticide use is truly necessary in the first place.  Unless we focus on whether a pesticide is actually necessary, all other issues are merely window dressing for perpetual pesticide use. 
  • SPM proposes to identify “Priority Pesticides” for possible substitution without any clear definition of “Priority Pesticides,” a process that is ripe for manipulation. Given the substitutions that are occurring now, we cannot assume that further substitutions would be less toxic. SPM puts the classification of “Priority Pesticides” into the hands of “stakeholders” without clearly identifying who stakeholders are.  SPM says “stakeholders” were involved in the development of the proposed policy.  Those stakeholders included only users and promoters of pesticide use.  There was no representation on the Urban Sub-Group of organizations such as Californians for Pesticide Reform, California Environmental Health Initiative, Beyond Pesticides, Center for Environmental Health, Environmental Working Group, etc.  Nor was there any visible expertise in the fields of science that are capable of analyzing and evaluating the impact of pesticides, such as soil science, endocrinology, toxicology, entomology, botany, biology, or horticulture.  SPM ensures that this exclusion will continue during the implementation phase by suggesting that “experiential and observational” knowledge should be represented on an equal footing with undefined “science.”  The word “science” is being used and abused by advocates for pesticide use who dangle it as a magic talisman, conferring fraudulent credibility. 

My entire public comment is available here:

The Oxalis Obsession

As a long-time reader of Jake Sigg’s Nature News, I am very familiar with his passionate crusade against Oxalis pes-caprae.  When oxalis appears in the landscape in January, Jake gears up his campaign again. This year the Westside Observer published an article by Jake about oxalis that reaches a new level of urgency and asks land managers to increase their use of herbicides to kill the plant.

In the past, Jake has advised careful and relentless hand-pulling of oxalis with its bulb intact.  Now he acknowledges that hand-pulling is useless to eradicate oxalis.  Although herbicides have been used on oxalis in San Francisco’s parks for 25 years, Jake now wants MORE herbicides to be used. Over 20% of all herbicide spraying by the Natural Resources Division (NRD) of the Recreation and Park Department was applied to kill oxalis in “natural areas” in 2022. NRD sprayed oxalis 35 times in 2021 and 38 times in 2022.

Spraying Garlon on Twin Peaks in San Francisco, February 2011

From January to March, virtually all the herbicides sprayed by NRD in the so-called “natural areas” were sprayed on oxalis.  If it were possible to eradicate oxalis with herbicide, why is there more oxalis now than there was 25 years ago, when NRD (then known as the Natural Areas Program) started spraying herbicides in the “natural areas?”  A lot of herbicide has flowed under the bridge in the past 25 years, but oxalis thrives. What is the point of pouring more herbicide under the bridge of sighs?  We’re pouring more fuel on the fire with nothing to show for it. 

One of many pesticide application notices on oxalis in Glen Canyon Park in February 2023.

The University of California Integrated Pest Management Program explains why it’s not possible to eradicate Oxalis pes-caprae with herbicides: “Several postemergent herbicides including triclopyr and fluroxypyr (selective for broadleaf plants) and glyphosate and glufosinate (nonselective) effectively kill the top growth of this weed but are harmful to most ornamentals, so be careful these herbicides don’t drift onto desirable plants. These herbicides don’t kill the bulbs, and regrowth from bulbs should be expected.” In other words, you can kill the above-ground top growth and other non-target plants in the vicinity, but you won’t kill the oxalis. 

Chemical Warfare?

On one hand, Jake urges public land managers to escalate chemical warfare against oxalis.  On the other hand, he accuses oxalis of “chemical warfare” (AKA allelopathy), secreting chemicals that kill other plants. This accusation is pure speculation on Jake’s part.  He offers as “evidence” of his speculation that after oxalis dies back in April “we’re left with bare ground for the rest of summer and autumn.”  He ignores the obvious fact that annual spraying of gallons of herbicide on oxalis in the “natural areas” could be causing the bare ground. It has apparently not occurred to him that many herbicides are non-selective, killing everything they touch, not just targeted plants. And those herbicides that claim to be selective are very mobile in the soil, capable of killing adjacent plants through their roots.  If you don’t want to see bare ground, don’t spray herbicides!

Jake asks for more research on how oxalis interacts with other plants in his article published by Westside Observer. He is apparently unaware of the research that has been done by scientists at University of Montana to address the question of how competitive oxalis is in plant communities that include native plants:  “Oxalis is a poor competitor. This is consistent with the preferential distribution of Oxalis in disturbed areas such as ruderal habitats, and might explain its low influence on the cover of native species in invaded sites.

The study explains why oxalis does not suppress the growth of other plants, including natives.  Oxalis makes more phosphorous available in the soil, which essentially acts as a fertilizer for other plants“These results are consistent with our field data and suggest that Oxalis may improve P availability in the field.”

This study was published in 2007.  It found that Oxalis pes-caprae does not suppress the growth of other plants and, in fact, increases nutrients in the soil.  Jake apparently doesn’t know about this study and related studies that found that pollinators are as interested in O. pes-caprae as they are in native plants.

Jake’s accusation that oxalis is waging “chemical warfare” against native plants does not come out of nowhere.  The same accusation was used against eucalyptus trees for decades until a definitive empirical study proved that eucalyptus is not allelopathic.  The California Invasive Plant Council removed that accusation from its evaluation of Blue Gum eucalyptus in 2015 (along with the accusation that eucalyptus kills birds).  As the readers of Jake’s Nature News know, his hatred of eucalyptus is second only to his hatred of oxalis.  There was never evidence that eucalyptus is allelopathic and there is no evidence that oxalis is allelopathic.

Does biodiversity justify poisoning nature?

Jake justifies his crusade against oxalis based on his belief that its existence threatens biodiversity.  Since there is no evidence that oxalis kills other plants, there is no reason to believe its existence threatens biodiversity.  

Jake also asks us to include only native plants in the measure of biodiversity, but he is alone in that belief.  Scientific measurements of biodiversity include all species of plants and animals, whether considered native or non-native.  The Recreation and Open Space Element of San Francisco’s General Plan explicitly acknowledges that both native and non-native plants contribute to biodiversity:  “Parks and open spaces in San Francisco include both native and non-native species, both of which can contribute to local biodiversity.” (Policy 4.1, Recreation and Open Space of San Francisco General Plan)

Jake ups the ante against oxalis by claiming that wildlife requires solely native plants, a fundamental tenet in native plant ideology.  Again, this claim is unsupported by evidence.  As Professor Art Shapiro (UC Davis) says in his Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions, “Most California natives in cultivation are of no more butterfly interest than nonnatives, and most of the best butterfly flowers in our area are exotic.”

coyote hunting in oxalis field. Copyright Janet Kessler

On one hand, Jake claims that oxalis deprives birds and other foragers of food.  On the other hand, Jake acknowledges that oxalis is foraged by gophers and scrub jays (based on one observation).  Jake wants it both ways because that serves his purpose. 

If native plants were any benefit to wildlife, that benefit is quashed by the widespread use of herbicides being used in the “natural areas.”  For example, Himalayan blackberries are an important source of food for birds and other wildlife in San Francisco’s parks and are also eaten by children visiting the parks.  The blackberries are routinely sprayed with herbicides in the so-called “natural areas.”  Wildlife is exposed to the herbicides and they are also deprived of important sources of food.

A recent survey of 24,000 gardens in the UK found that pesticide use had a significant effect on bird life. The study found that gardens that used pesticides had fewer species of birds than similar gardens that did not use pesticides:

“Pesticide spraying impacted the positive effect [surrounding habitat quality] had on bird richness. Specifically, ‘species richness [number of species] increases with the surrounding quality, both for gardens that do not use pesticides and for gardens that applied pesticides, but this effect is significantly less strong when pesticides are applied’ the study indicates. Scientists zeroed in on three active ingredients: the weed killer glyphosate, the neonicotinoid insecticide acetamiprid, and the synthetic pyrethroid deltamethrin as resulting in the most damaging pesticide impacts to bird species’ richness.” Note that the study’s definition of “surrounding habitat quality” made no distinction between native and non-native plants.  The British are not strong supporters of native plant ideology. 

Nativists keep using huge quantities of herbicide to kill vegetation they don’t like, while also claiming that their eradication projects benefit birds. This is a fundamental contradiction. Their eradication projects are harmful to birds and other creatures that live in our parks and open spaces.

Jake’s Lament

In his article, Jake laments that people are accepting changes in the landscape because they don’t remember what the landscape looked like 100 years ago.  His “baseline view” of what landscapes should look like is much further in the past than most people’s memories of the landscape. 

The climate has changed significantly in the past 100 years.  When the climate changes vegetation changes.  We should welcome the changes because they are required for the survival of any landscape.  When the climate changes, plants and animals must move, adapt, or die.  The changing landscape is an indication that plants are adapting to changing conditions. 

We cannot stop evolution, nor should we try.  Herbicides are a futile attempt to stop evolution.  Herbicides cannot stop evolution, because plants evolve a resistance to them.  After 25 years of constant herbicide use in San Francisco’s parks and open spaces, we should assume that they are less effective every year. 

While San Francisco’s Recreation and Park Department has significantly reduced its use of herbicides since 2010, the Natural Resources Division that is responsible for the “natural areas” has not. Natural Resources Division is now using more herbicides than the rest of the parks. Source: San Francisco IPM Program, Department of Environment

Wild by Design: A history of ecological restoration in the U.S.

“This is a superb book. Laura Martin’s research takes us where no restoration literature has gone before, asking, ‘Who gets to decide where and how wildlife management occurs?’ Martin tackles this question with unmatched clarity and insight, illuminating the crucial discussions we must have to secure a future with thriving natural species and spaces.”—Peter Kareiva, President and CEO, Aquarium of the Pacific

The author of Wild by Design, Laura J. Martin, is a professor of environmental history at Williams College.(1) She has written a comprehensive history of ecological restoration in the US that is consistent with my own observations of the restoration industry in the past 25 years.  It’s a story of the gradual transition from a conservation ethic to a preservation ethic and finally to the restoration ethic that we see today.  The story is punctuated by milestone federal laws and actions that facilitated the transition.  Environmental non-profits and academic ecologists used those laws to professionalize and monetize the restoration industry that exists today. 

By the end of the 19th Century, the public began to react to the environmental degradation caused by unregulated resource extraction.  In 1902, a survey of naturalists around the country determined there were 1,143 bison left in the country; virtually all were in captivity.   The American Bison Society was founded in 1905 in reaction to the disappearance of bison in America.  Their activism led to the creation of federal game reserves on former Indian reservations where captive bison were introduced.  The game reserves were the model for the National Wildlife Refuge system that was greatly expanded by President Teddy Roosevelt.

A photograph from 1892 of a pile of American bison skulls in Detroit, Michigan waiting to be ground for fertilizer or charcoal. (Photo Wikimedia Commons)

The creation of the Wild Flower Preservation Society (WFPS) in 1901 was modeled on the successful campaign of the Audubon Society to save birds killed to serve as ornaments on fancy hats.  It was as much a campaign to shame women into abandoning the fashion fad as it was an effort to legally ban the practice.  Likewise, the Wildflower Preservation Society applied social pressure.  They were critical of organized excursions to visit wildflowers because they picked and trampled the wildflowers.  WFPS said that “Weddings are a new menace to our native plants” because of their use of wild flowers. Their criticism was initially aimed at their own community, but “it moved toward policing the behavior of so-called new immigrants to the United States—especially children.”  The moralistic scolding by these early native plant advocates was a preview of the finger-wagging now aimed at those who choose to plant a diverse garden. 

These advocacy organizations are precursors to the many environmental non-governmental organizations that are influential in pressuring government to invest in ecological restorations today.

Conservation and Preservation

The goals of conservation and preservation are similar, but some differences were observable in the past 200 years.  Both ethics are committed to protecting the environment, but conservation allows the sustainable use of natural resources while preservation protects nature from use.  The presidencies of both Teddy and Franklin Roosevelt were committed to conservation. 

Teddy Roosevelt created the US Forest Service based on the premise that government can and should regulate public lands to manage natural resources.  Franklin Roosevelt’s conservation programs were based on the same principle, but were motivated by the economic emergency of the depression as well as the environmental disaster of the Dust Bowl in the Midwest.  The Civilian Conservation Corp (CCC) was created to provide jobs as well as to plant a “shelter belt” of trees across the Midwest of the country as a windbreak to stop dust storms (and many other projects).  Ecologists were critical of CCC projects because they expanded recreational opportunities and put “a stamp of man’s interference on every natural area they invade.” They preferred to exclude humans and their activities from nature. This is another early indicator of the conflicts between preservation and conservation that persist to the present day.

Sharp Park, Pacifica, CA. Photo by Erica Reder, SF Public Press

Government investment in ecological research

Ecological research in the United States was fundamentally altered after World War II, which ended with the beginning of the atomic era.  Atomic bombs were dropped on Japan to end the war without much thought given to the consequences.  After WWII, the federal government made big investments in science, creating the Atomic Energy Commission and the National Science Foundation, which funded ecological research to study the impact of radiation on the environment and those who live in it.  Conservation Sense and Nonsense published an article about those studies and the impact they had on ecological research. 

These studies legitimatized destruction of ecosystems to study effects of the destruction and the concept was expanded from radiation to pesticides in the 1960s.  They also provided funding to the academic profession of ecology that was small and is now enormous.  The dependence of ecological studies on government funding remains to this day and government funding of ecological projects has created the restoration industry that now extends far beyond academia.  Destruction of existing habitat is still considered the prerequisite to restoring a historical landscape.  Often, destruction is the first and only stage of the project because of the persistent fantasy that the native landscape will regenerate without further help. 

In the late 1960s Daniel Simberloff tented and fumigated 6 mangrove islands off the eastern short of Florida with methyl bromide to kill all life on the islands.  The objective of the project was to study how long it would take to repopulate the islands with insects.

From Conservation to Restoration

The post-war economic boom of the 50s and 60s greatly increased the impact of human activities on the environment.  The federal government built a vast highway system that fragmented and disrupted ecosystems.  We built huge dams, and channeled riparian ecosystems.  Open space was rapidly covered by housing and industrial development.  Wetlands were drained and filled with rubble to create more land.

People who cared about the environment began to react to the loss of nature and wildlife that lives in nature.  Although Aldo Leopold is idolized by the native plant movement, his concern about the degradation of nature was primarily for wildlife.  His interest in vegetation was as habitat for wildlife.  He was opposed to government programs devoted to killing animals perceived as predators of game animals because he believed that wildlife is best served by expanding their habitat.  In fact, he was opposed to the expansion of government’s role in conservation because “he believed restoration would be most efficient and effective if pursued by private citizens.” He did not prefer native plants because “Farmers had the opportunity to conserve plants such as ragweed and foxtail (an introduced grass), ones ‘on which game, fur, and feather depend for food.’”  In other words, in the 1940s one of the icons of the native plant movement knew that wildlife is not dependent upon native plants for food.  One wonders if native plant advocates have actually read Leopold’s treatise, A Sand County Almanac. 

Aldo Leopold’s son, Starker Leopold, had as much impact on conservation in the United States as his father.  In 1963, he published the Leopold Report that changed the direction of conservation in the National Park Service.  The Leopold Report recommended a goal for national parks of maintaining historical conditions as closely as possible to those of “primitive America.”  When the Leopold Report was adopted as official policy by the National Park Service in 1967, it committed NPS to restoring park lands to pre-settlement conditions. NPS officially changed this policy in 2021, but we don’t see any change locally in their projects because NPS is decentralized and local parks are autonomous.

Restoration Goals

Professor Martin says that “historical fidelity did not become a widespread restoration goal among ecologists and environmental organizations until the 1980s.”  The arrival of Columbus in the new World in 1492 was arbitrarily selected as the date after which all new plant species were “deemed nonnative, unwanted reminders of human (colonist) presence and activity.”  On the West Coast, 1769 is the equally arbitrary date to confer non-native status because it is the date of the first Spanish expedition to California. 

Many now question the goal of replicating historical landscapes.  After 40 years of effort, there is a growing recognition that it is not a realistic goal, especially in a rapidly changing climate.  The Society for Ecological Restoration has changed its definition of ecological restoration from “the goal of intentionally altering a site to establish a defined, indigenous, historic ecosystem” in 1990 to “the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed” in 2002.  Try telling that to the restorationists on the ground who are still trying to eradicate naturalized non-native plants that have been here for nearly 200 years.  Non-native annual grassland in California is a case in point. It has been repeatedly burned, mowed, plowed, and poisoned for 25 years without any visible progress toward native perennial grassland.   

Blaming non-native species

Around the same time that historical fidelity was identified as the goal of “restorations,” land managers and ecologists decided that the existence of non-native species is the main threat to native species.  I suppose the “logic” was that the main difference between historical landscapes and present landscapes is the existence of non-native species.  Concern about non-native species spread among federal agencies such as the National Park Service and The Nature Conservancy (TNC) began aggressive campaigns to kill non-natives, “which were newly framed as the main threat to wild species…nativity would become a precondition to wildness—of plants and animals both.”   TNC’s methods have become increasingly deadly and destructive: using fire and herbicides to kill plants, poisoning honeybees, aerial hunting of sheep, pigs, and goats.  As a former donor to TNC, their methods finally became intolerable to me.

Professor Martin believes that the identification of non-native species as the scapegoat was not based on experimental evidence, but merely a description of the strategies used by public land managers, as well as The Nature Conservancy.  Non-native species were a convenient scapegoat because they were easily identified and were an easy substitute for identifying and remediating the underlying conditions causing so-called “invasions.”  “Although the role of invasive species in native species extinction has since been challenged by some ecologists, the influence of this fear on species management has been enormous…The US federal budget for invasive species management increased by $400 million between 2002 and 2005, for example.”   

Endangered Species Act

The Endangered Species Act (ESA) was passed in 1973, along with companion laws such as the National Environmental Protection Act and others.  These federal laws created more funding opportunities for ecological projects as well as the legal justification for ecological restoration projects.

Federal laws permit the reintroduction of legally protected plant and animal species to places where they no longer exist.  The ESA confers the same protections for reintroduced species as it does for naturally occurring species.  Such reintroductions have become a tool for the restoration industry.  I have seen that strategy used in the San Francisco Bay Area.  If we had not been successful in preventing the reintroduction of a legally protected turtle, it would have justified the destruction of the non-native forest in my neighborhood park because the turtle requires unshaded nesting habitat within 500 feet of the water source in the park. The park remains largely forested because that is one of the few battles we have won in 25 years. Reintroduced, legally protected species are the Trojan horses of ecological restorations.

Compensatory mitigation is an equally powerful tool for the restoration industry.  Federal law requires an Environmental Impact Statement (EIS) for projects that will have a significant impact on the environment, such as big developments like building Disney World in Florida.  Disney World was built on an enormous wetland that was lost by the development of the park.  The EIS for the project agreed that the impact would be great, but it “mitigated” the impact by requiring Disney to fund the creation of a new wetland in a distant location.   

The funding generated to create fake wetlands built a new industry of commercial companies to design and build them.  Academic restoration ecologists questioned the functional equivalency between created and natural wetlands:  “’however accurate [the Comprehensive Everglades Restoration Plan] is the restored community can never be authentic.’”  The tension between commercial and academic restorationists continues today.

The Society for Ecological Restoration published findings that mitigation wetlands were not functionally equivalent to the wetlands they were meant to replace.  In Florida only half of the promised mitigation projects were actually built. Those that were built were colonized by “undesirable plant species” such as cattail and melaleuca in 32 of 40 projects.    

Projects that earn carbon credits are creating the same opportunities to generate funding for restoration projects in distant locations.  The Nature Conservancy was successful in defining carbon offsets as an international market when the Kyoto Protocols were signed in 1997.  They understood that a reforestation project would be cheaper in Costa Rica (for example) than a comparable energy efficiency project in the US.  Such distant projects don’t benefit those in the US who now have a power plant in their backyard that is being offset by a forest in Costa Rica. 

It’s a game for those who know how to play.  I have witnessed local examples in the Bay Area.  An oil spill in the bay generated millions of dollars of compensatory damages to fund unrelated “restoration” projects.  How does planting eel grass compensate for hundreds of birds killed by the oil spill?  When the San Francisco airport expanded runways, the airport had to pay compensatory mitigation that funded the restoration of native plants at India Basin in San Francisco that hardly compensates for the increased air traffic enabled by the new runway.   


Professor Martin is surprisingly frank about the future of ecological restoration in America:

“Whatever paths restorationists choose, restorations must happen in tandem with other changes in human behavior.  If we don’t reduce the ongoing harms of racism, fossil fuel burning, overconsumption by the wealthy, and toxic industrial chemicals, restoration will offer no more than a temporary repair, a way to move a problem to some other place or time.”

I would go one step further in my assessment of the restoration industry.  I would say that the methods used by restorationists are directly contributing to environmental degradation. 

Professor Martin asks the right questions in her concluding chapter:  “Who benefits from restoration?  Who is harmed?”  Those who earn their living in the restoration industry are the primary beneficiaries. According to a 2015 study entitled “Estimating the Size and Impact of the Ecological Restoration Economy,” environmental regulation has created a $25 billion-per-year restoration industry that directly employs more people than coal mining, logging or steel production.  Given recent investments in restoration projects of billions of dollars by California and federal infrastructure funding, this figure is undoubtedly an underestimate. 

Who is harmed?  Wildlife and humans are harmed by the destruction of useful habitat with herbicides.  Harmless animals and plants are killed because they have been arbitrarily classified as “invasive.” And all Americans are harmed by the waste of public funds that could be used to benefit society and/or the environment. 

(1) Laura J. Martin, Wild by Design:  The rise of ecological restoration, Harvard University Press, 2022.  All quotes are from this book.

The Destructive Origins of Ecological Field Studies

Laura J. Martin is an environmental historian at Harvard University.  She wrote two articles (1,2) about the origins of ecological field studies that might help explain the destructive methods still used today by some ecologists.  Professor Martin “contends that the history of ecosystem science cannot be separated from the history of nuclear colonialism and environmental devastation in the Pacific [Nuclear Testing] Grounds” (2)

When the US dropped two atomic bombs on Japan in 1945, little thought was given to the consequences of atomic bombs because ending the war in the Pacific was the only consideration.  Japan surrendered to the US less than one month after the bombs were dropped, effectively ending World War II. 

Few doubt that the use of atomic weapons was instrumental in ending World War II.  After the war, there was a more sober effort to determine the consequences of using atomic weapons.  Some believed that nuclear weapons might replace conventional warfare.  Others wanted to understand the impact on life on the planet before making such a momentous decision.  This effort was focused on practical considerations such as the impact on the world’s fisheries and food supply.  The objective of their initial studies was less concerned about long-term consequences for the environment such as the duration of impacts on living creatures and the environment in which they live.

The US federal government invested heavily in the sciences after World War II. The Atomic Energy Commission (AEC) was established in 1946 and the National Science Foundation (NSF) in 1950.  The availability of federal grant funding for academic institutions “dramatically reconfigured the relationships among federal, academic, and corporate spheres.” (2) Increased federal funding greatly increased the number of academic research projects.

Between 1945 and 1970, the US detonated 105 nuclear weapons. The Atomic Energy Commission and later the National Science Foundation paid academic ecologists to conduct field studies at the test sites to determine the impact on animals. 

In 1963 the US, Soviet Union, and Great Britain signed a Partial Test Ban Treaty that prohibited all non-wartime detonations except for those done below ground.  Testing of the effects of radiation by academic scientists continued because the AEC mass produced radioisotopes and distributed them to American institutions.  Scientists were no longer constrained to field sites where atomic bombs had been detonated.

“Thus began a period in which ecologists purposefully destroyed ‘ecosystems’ to study how they recovered.”

Laura Martin, “The World in Miniature”

The availability of radioisotopes made laboratory testing possible, but it also enabled large-scale atomic irradiation experiments such as a forest irradiation project in Georgia that exposed 300 acres of forest to an air-shielded reaction (?) that produced radiation levels comparable to expected fallout following a nuclear catastrophe.  The purpose of that experiment was to determine the impact of radiation on forests.  The findings were that some tree species were more vulnerable to radiation than others.  This finding contributed to the hypothesis “that the greater number of species in an ecosystem, the better that system will be ‘adjusting to stress.’” (1) This is the familiar theory that greater biodiversity enhances resiliency of ecosystems against stressors such as climate change.  It remains a cornerstone of conservation science. 

These studies are also responsible for the knowledge that radiation—and many other toxic substances such as chemicals—bioaccumulate, first described publicly in 1955, according to Martin.  Many toxic substances persist in our bodies throughout our lifetime.  The longer we are exposed to them, the more dangerous they are to our health.  Women who were exposed to DDT before it was banned in 1972 still have higher levels of DDT in their bodies than women born after 1972.  Many toxic chemicals also bioaccumulate in food webs.  Top predators in the food web are more heavily burdened with poison than animals at the bottom of the food web because of biomagnification

Using pesticides to study impacts and recovery

The concept of destroying an ecosystem for the purpose of studying impacts and recovery from impacts was soon extended to using pesticides.  In a study funded by NSF in the 1960, herbicides were repeatedly applied to clear-cut plots in the White Mountain National Forest to compare the runoff from “disturbed” watershed with “undisturbed” control watersheds.  “They concluded that forest clear-cutting led to the leaching of nutrients from the soil, and ultimately, algal blooms in downstream waters.” (1) (Yet, 60 years later, spraying clear-cuts with herbicides is still the norm in the timber industry.) 

Destructive methods used by Daniel Simberloff

The first publication (3) in 1969 of Daniel Simberloff’s academic career was a report of his Ph.D. dissertation project under the direction of EO Wilson at Harvard University.  He tented and fumigated with methyl bromide 6 mangrove islands off the Eastern shore of Florida to kill all the insects.  His objective was to study how long it would take for insects to recolonize the islands.

Although Simberloff monitored the islands for only one year, he concluded, “The colonization curves plus static observations on untreated islands indicate strongly that a dynamic equilibrium number of species exists for any island.” (3)  This is an example of the generalized conclusions of ecological studies noted by Professor Martin:  “With ecosystem studies, ecologists claimed that fieldwork conducted in one place could be used to understand other distant and different places.  The Pacific Proving Grounds became a model for lakes in Wisconsin, rain forests in Panama, deserts in China…” (2) 

Some 60 years and thousands of ecological studies later, such generalizations are rarely considered credible.  To quote one of the academic scientists who advises me, “If you study a specific site, you know something about THAT site at THAT specific point in time.”  Nature is too dynamic to reach a sustainable equilibrium and its complexity cannot be accurately generalized.  The concept of a sustainable equilibrium ecosystem was rejected by scientists long ago.

Laura Martin says of Simberloff’s study, “Destruction thus became a method of studying ecosystems. As Eugene Odum put it: ‘ecologists need not feel bashful about attacking ecosystems so long as they observe the rules of good science.’” (1)

Methyl bromide used by Simberloff in his thesis project is known to deplete the ozone layer of the atmosphere that shields the Earth from harmful Ultraviolet light that causes skin cancer.  Its use was severely restricted by an international treaty in 1989.  However, it is still used in the US for agricultural crops as a soil sterilant that kills all living organisms in the soil. 

The federally mandated Material Safety Data Sheet for methyl bromide says it is acutely toxic to aquatic life at the highest danger rating (Category 1). 

Nearly 60 years after the publication of his Ph.D. study, Daniel Simberloff remains one of the most vocal advocates for the eradication of non-native plants and animals.  With few exceptions, those eradications require the use of pesticides.  Simberloff may not have known the damage that methyl bromide does in the environment at the time of his study, but surely he knows or should know now.  Yet, he is still committed to the eradication of non-native plants, projects that require the use of pesticides.

Many ecological studies and associated “restoration” projects adopt the same viewpoint that destruction is a justifiable method of studying and “restoring” ecosystems.  “Restoration” projects often begin by killing all non-native plants with herbicides before attempting to create a native landscape.   Rodenticides and insecticides are used to kill non-native animals with the understanding that many native animals will inevitably and unintentionally be killed.  The Endangered Species Act accommodates the by-kills of these projects by issuing permits for “incidental takes.”  The law and the scientific community make a distinction between killing individual animals and killing animals on a scale that threatens the survival of the species. 

Killing and destruction were established as legitimate scientific tools over 70 years ago.  Given what we know now about pesticides and radiation and at a time when habitats are being destroyed by human activities and climate change, is it time to question the legitimacy of habitat destruction as a scientific tool?

A Preview

Professor Martin is also the author of her recently published book, Wild by Design:  The Rise of Ecological Restoration.  I look forward to reading it.  Meanwhile, I hope Professor Martin’s papers about the destructive origins of ecological field studies are a preview of her book. 

Update: I have read and summarized Wild by Design in this article, published January 7, 2023.

Happy New Year! We hope 2023 will be a more peaceful year.

  1. Laura J. Martin, “The World in Miniature”: Ecological Research at the Pacific Proving Grounds and the Materialization of Ecosystems, 2016 (unpublished)
  2. Laura J. Martin, “Proving Grounds: Ecological Fieldwork in the Pacific and the Materialization of Ecosystems,” Environmental History 23 (2018): 567–592
  3. Daniel Simberloff, EO Wilson, “Experimental zoogeography of islands: the colonization of empty islands,” Ecology, 1969

Revelations of the 2022 California Invasive Plant Council Symposium

I have attended the annual symposiums of the California Invasive Plant Council (Cal-IPC) for 5 years.  I have always learned something new and the most recent symposium in November 2022 was no exception.  This year there was a lot of important information about herbicides that are widely used to eradicate non-native plants. 

Several presentations reviewed the California laws that regulate pesticide use in California. (Slides for one of those presentations are available HERE.) The laws are designed to reduce risks of exposure to both applicators and the public. 

The presentations emphasized the importance of legally mandated personal protective equipment (PPE) for applicators.  The minimum PPE required by California law is protective eyewear and chemically resistant gloves:

Source: 2022 Cal-IPC Symposium

The toxicity of pesticides is rated by federal law as “Caution,” “Warning,” or “Danger,” with “Danger” indicating the most toxic and “Caution” the least toxic.  These ratings are defined as signal words.  Signal words of “Warning” or “Danger” require the applicator to also wear protective coveralls, in addition to protective eyewear and gloves. 

Other types of PPE may be required by the product label, shown in this picture:

Source: 2022 Cal-IPC Symposium

Comparing the toxicity of organic and synthetic herbicides

Signal words can be used to compare the acute toxicity of different products.  For example, the signal word on glyphosate products is “Caution,” indicating that it is considered less acutely toxic than other herbicides with higher toxicity ratings of “Warning” or “Danger.” Signal words are not a measure of long-term health damage of pesticides, such as cancer or kidney damage. Epidemiological studies of long-term health effects of pesticides are hotly disputed and are usually dismissed by the manufacturers of pesticides.

When glyphosate products were rated as a “probable human carcinogen” by the World Health Organization and tens of thousands of product liability lawsuits were filed by users of glyphosate products with cancer, there was a public backlash against the use of glyphosate partly because it is the most widely used herbicide on the market.  Glyphosate is found in most of our food and in the urine of most people. The health damage done by glyphosate is the result of 40 years of widespread use by agriculture. Glyphosate’s “Caution” signal word does not reflect the long-term effects of its use.

Consequently, glyphosate has been banned in many places all over the world. Los Angeles County has banned glyphosate. Locally, it is no longer used by East Bay Regional Park District (EBRPD) in developed park areas such as picnic areas, parking lots, and playgrounds.  Although EBRPD made an exception for “invasive” plants outside developed areas, they have significantly reduced their use of products containing glyphosate.  They are using more “organic” herbicides.  Marin County banned the use of glyphosate.  They are using exclusively organic herbicides.

What is the difference between synthetic and organic pesticides?  In general, organic products are derived strictly from sources in nature with little or no chemical alteration. Synthetic pesticides are products that are produced from chemical alteration. 

Are organic pesticides less toxic than synthetic pesticides?  The general public tends to assume that organic pesticides are less toxic than synthetic pesticides, such as glyphosate.  Based on the signal words the EPA assigns to pesticides to evaluate toxicity, organic pesticides are not necessarily less toxic than some synthetic pesticides.  Remember the signal words are “Danger” (the most toxic), “Warning,” and “Caution” (the least toxic.) 

Several presentations at the Cal-IPC conference compared the toxicity of organic and synthetic pesticides, using signal words as a proxy for toxicity.  This is a slide from one of the presentations:

I also compared the signal words of the organic products used by Marin County and East Bay Regional Park District.  Although they are using some organic products not evaluated by the presentation at the Cal-IPC Symposium, many of the organic products they are using have a “Warning” signal word, which means the EPA considers them more toxic than glyphosate. 

Clearly organic herbicides are not necessarily less toxic than synthetic herbicides and many organic herbicides are more toxic than glyphosate.

Comparing the efficacy of organic and synthetic herbicides

Are organic herbicides as effective as synthetic herbicides?  One of the presentations made at the Cal-IPC Symposium reported the results of a field study comparing the effectiveness of three organic herbicides with three synthetic herbicides, all with “Caution” signal words: 

Here’s a description of the field trial:

Here are the results of the field trial (one organic herbicide was removed from the field trial when glyphosate was reported as an undisclosed ingredient in the product):

WeedZap and Fireworxx are the organic herbicides used in the field trial.  The organic herbicides used in the field trial were found to be less effective than synthetic herbicides considered equally toxic.

This finding was corroborated by a publication of the UC Nursery and Floriculture Alliance, entitled “Organic Herbicides –Do they Work?”  The short answer to that question is, not very well:

  • “Organic herbicides kill weeds that have emerged but have no residual activity on those emerging subsequently. Further, while these herbicides can burn back the tops of perennial weeds, perennial weeds recover quickly.”
  • “These organic products are effective in controlling weeds when the weeds are small but are less effective on older plants.” The organic herbicides were significantly less effective when weeds were more than 12 days old.
  • “…broadleaf weeds were easier to control [with organic herbicides] than grassy weeds.”

Comparing the cost of organic and synthetic herbicides

The field study comparing organic and synthetic herbicides also compared the costs of these different product types:

In other words, organic herbicides are considerably more expensive than synthetic herbicides

The publication of the UC Nursery and Floriculture Alliance agrees:  organic herbicides “are expensive and may not be affordable…Moreover, because these materials lack residual activity, repeat applications will be needed to control perennial weeds or new flushes of weed seedlings.” 

Clearly, organic herbicides are not a substitute for synthetic herbicides because they are not less toxic, not as effective, and are very expensive.  Cal-IPC considers that assessment of organic herbicides a justification for continued use of synthetic herbicides.  I consider it an argument for declaring a truce in the war on “invasive” species.  We have waged that war for over 30 years.  We have not won that war.  In fact, we lose ground every year.  We have done more damage to the environment with our chemicals than the “invasive” species did.  We have reached a dead end.

Herbicides and Climate Change

The most valuable lesson I learned at the Cal-IPC Symposium was that climate change is making herbicides less effective.  Higher temperatures and higher levels of CO₂ are reducing the effectiveness of herbicides. This revelation was mentioned only briefly in a presentation by Regional Invasive Species and Climate Change (RISCC) Management Networks.  A search of the scientific literature substantiated that revelation:

These studies are just a small selection of the studies that respond to a search for “impact of heat and CO₂ levels on herbicide efficacy.”  They all point to yet another reason why the chemical crusade on introduced plants is a dead end. 

Climate change is a reality and it is here to stay.  Climate change has changed the ranges of where native plants can survive and it has made it impossible to destroy the non-native plants that are capable of surviving in the changed climate.  Switching from one poison to another will not overcome the forces of evolution, which dictate that vegetation changes when the climate changes. 

The Timber Wars in the Pacific Northwest could have been avoided

Tree Thieves (1) is a non-fiction version of Damnation Spring, a novel that tells the story of the Timber Wars that ended with the death of the logging industry in the Pacific Northwest in the 1970s, 80s, and 90s.  Although the industry collapsed throughout the Pacific Northwest, both books focus on the redwood forests of coastal Northern California. 

Sequence of Events

When the timber industry began in earnest after the Gold Rush of the 1850s, there were said to be 2 million acres of redwood forest on the coast of California.  The demand for timber during the Gold Rush fueled the unrestricted clear-cut methods that decimated the forest, provoking a backlash.

The city-slickers who established the Save the Redwoods League in 1918

The National Park Service invited three well known conservationists to visit the redwood forests of Northern California, which led to the creation of the Save the Redwoods League in 1918.  Two members of that team–Madison Grant and Henry Osborn—were also advocates for eugenics, the control of human reproduction for the purpose of increasing characteristics considered desirable.  The author of Tree Thieves, Lyndsie Bourgon, describes their purpose for creating the Save the Redwoods League: “They considered protecting the redwoods as part of a mission to enshrine White, masculine dominance over the wilderness.” (1) Save the Redwoods League purchased several parcels of redwood forest for preservation, setting the stage for the continuing perception of environmentalism as the hobby of wealthy city dwellers, with little understanding of the lives of those who live and work in resource extraction industries such as forestry.  The League has acquired a total of 66 redwood forests as of 2018, according to Wikipedia. 

In the 1930s the government imposed restrictions on the timber industry that limited clear-cutting methods because of concern about dwindling timber stocks.  The industry returned to clear-cutting methods after World War II in response to the demand for new housing.  By 1968 90% of redwood forests had been logged, according to Tree Thieves.

Consequences of clear-cut logging

The author of Tree Thieves believes that the turning point leading to the Timber Wars was a flood in 1955 that triggered a landslide that “toppled 1,000 year old redwoods and covered the region in silt and mud.”  The landslide was the result of decades of clear-cutting the forest:  “During clear-cut logging, topsoil is lost and streams are bulldozed for roads…In Humboldt [County’s] forests, the root system could no longer contain the immense annual rainfall and waterways began to flood.  Mangled roots, lack of second growth, and flattened shrubs made the earth unstable and the construction of roads deep in the woods to transport logged wood had hastened erosion and habitat destruction.”

This is what remains of Orick, Ca. Google Earth

Clear-cut logging didn’t stop after the first flood and landslide and in 1964 another flood and landslide swept through the town of Orick.  The town of Orick is at the center of Tree Thieves’ telling of events.  Orick is said to be a Yurok word for “mouth of the river,” perhaps referring to Redwood Creek that bisects Orick. Yuroks were one of several tribes of Native Americans who were the first human inhabitants of the region.  At the height of the post-war timber boom, there were about 2,000 inhabitants of Orick.  The 2010 census downgraded Orick from a town to a “census designated place” with fewer than 400 inhabitants. 

These catastrophic floods alerted the Sierra Club to the issue of clear-cut logging and the government was becoming concerned about the environmental devastation it caused.  In 1968, the government established the Redwood National Forest, which ended logging in the park. The government believed—or said they believed–the park would create a tourist trade, replacing the logging economy.  Timber corporations were compensated by the government for the loss of their properties, but there wasn’t government relief for the loggers.

The Timber Wars

The promise of a tourist industry proved to be a fantasy, which forewarned the loggers of the consequences of expanding the national park that occurred in 1978.  This time the loggers fought back and environmentalists organized to engage in that war.  In the 1970s, Humboldt County became a rural refuge for hippies fleeing the druggy disorder of cities as described by Joan Didion in Slouching towards Bethlehem.  They were the foot-soldiers opposing the loggers in the Timber Wars.

Both sides of the Timber Wars engaged in violence and vandalism, as well as degrading rhetoric.  “ARE YOU AN ENVIRONMENTALIST, OR DO YOU WORK FOR A LIVING?” was a typical protest sticker worn by loggers.  One of the leaders of the environmentalists, Judi Bari, described the loggers as “the equivalent of the white racists in Mississippi…They’re being used by the system.  But they are people who are not real bright who have bought into it.”

The battle lines need not have been drawn between loggers and environmentalistsIf they had worked together to find a solution to environmental issues, the battle lines could have been the timber corporations vs. the government.  The decision to clear-cut and spray with herbicides was made by the corporations, not by the loggers.  Many of the loggers had learned their profession by taking individual trees in the forest, which quickly recovered from single tree removals.  They knew that clear-cutting was destructive and they probably would have been glad to return to less destructive methods of logging.  Many of them also knew that herbicides used for road clearance and destroying competing vegetation after clear-cuts were poisoning the watershed and sickening their community.  That aspect of the story is best told by Damnation Spring

If loggers and environmentalists had worked together to pressure the government to regulate the destructive aspects of the timber industry, the environmental issue could have been resolved without a war that permanently alienated both loggers and environmentalists.  Government has the right to regulate pesticide use and it could restrict clear-cutting, but it didn’t and it won’t.  The Timber Wars also alienated some people from environmentalism and others from the logging industry.  There is a lesson here for those who wish to learn it. 

The loggers were also disrespected by the government.  While the plan to expand the national park was being debated, the loggers organized a convoy of logging trucks across the country to Washington DC in 1977.  They carved a redwood log into the shape of a peanut, intended as a gift to President Carter, a former peanut farmer, hoping to engage him in a dialogue.  President Carter refused the gift and the request for a meeting.  He said the peanut-log was a waste of a valuable resource.  The logging convoy not only failed, but it subjected the loggers to abuse across the entire country and back.

The decision to expand Redwood National Park in 1978 incorporated the forests protected by the Save the Redwoods League and California state parks into a total of 139,000 acres, protecting approximately 45% of remaining redwood forests.  Once again, the timber corporations were compensated for the loss of their properties.  This time, the federal government tried to compensate loggers for the loss of their employment by funding a job training program, community development projects, watershed restoration, and direct compensation to unemployed loggers.   

The failure of the job retraining effort was very disappointing:  “By 1988, $104 million had been spent on about 3,500 people, of whom fewer than 13% had received retraining….’Never have so many given so much for so few,’ one critic noted of the funding.”

The fate of the loggers and their community

When spotted owls and several other forest species were designated as threatened species by the Endangered Species Act in the 1990s, much of the timber industry was also shuttered in Washington and Oregon.  Between 1980 and 1998, 23% of logging jobs were lost. 

Using the community of Orick in California as an example, Tree Thieves describes the consequences of the loss of the timber industry.  Many people moved away.  Those who remained pieced together a meager living of odd jobs.  Many of those odd jobs were criminal.  Poaching of whole trees in the national park is still common, but poaching the valuable redwood burls is more lucrative. 

Redwood burl. California State Parks

Redwood burls are the tree’s means of recovering from wounds.  The burls have artistic patterns in their wood grain that make them valuable to make furniture, art objects, and veneers for the dashboards of luxury cars.  The tree is damaged by the removal of its burls and is sometimes killed by the damage. 

Tree Thieves interviews many of the former loggers, now poachers.  They are an angry bunch who feel justified in their thievery.  Their livelihoods and self-respect have been taken from them and they have been subjected to decades of abuse by self-righteous environmentalists and government enforcement.  They now feel owed. 

Having won the Timber Wars, environmentalists are rarely directly engaged in confrontational encounters. Now the anger of dispossessed loggers is directed at government employees who are trying—with little success—to stop poaching and punish poachers.  Government employees are also imposing new restrictions on the communities surrounding the national park, opening new wounds.  For example, these poor communities are now prohibited from collecting drift wood on the beach, which was used to fuel wood-burning stoves in the past. 

Timber corporations were not blamed for the Timber Wars.  They were compensated by the government for the loss of their land.  They had already logged much of the land and didn’t see much future in the few forests that remained.  They were responsible for much of the loss of employment because they had mechanized much of the work and reduced availability of unlogged forests after clear-cutting for decades.  They walked away unharmed. 

Making, selling, and using methamphetamines is also a common way to survive in Humboldt County.  Those who choose that mode of survival frequently engage in other criminal behavior and their lives are often ruined in the process.

The marijuana trade in Humboldt County is also a popular career choice.  Ironically, the damage to the environment caused by large marijuana farms hidden in the forests is one of the consequences of the transition from a logging economy to an odd-job economy.

This scenario is probably similar to many other small towns and rural communities in America.  There are devastated communities in former coal country and in the rust-belt where manufacturing industries have been closed as the result of global trade agreements that enabled industries to move to countries with lower labor costs.  Those are the places where angry people no longer trust the government, where environmentalists and other “experts” are hated.  And those are the places where desperate, resentful people have turned to an angry, resentful politician to lead our country.  We reap what we have sown.

  1. Lyndsie Bourgon, Tree Thieves:  Crime and survival in North America’s woods, Little, Brown Stark, The Hatchett Group, 2022.  All quotes are from this book.  Some factual information is from Wikipedia.   

Money and Fire: 2022 Conference of California Native Plant Society

The California Native Plant Society (CNPS) held a conference in October for the first time since 2018.  There were two main themes of the conference:

Money:  The State of California is making a huge investment in the environment with many interrelated goals:

  • “30 X 30” is shorthand for the goal of protecting 30% of California’s land and coastal waters by 2030.
  • Developing “nature-based solutions” to address the threats of climate change.
  • Vegetation and forest management to reduce wildfire hazards.
  • Protecting and enhancing California’s biodiversity.

Fire:  The frequency and intensity of wildfire is of concern to all Californians, but the California Native Society has a particular interest in fire because it is viewed as a tool to enhance native plant abundance and control the spread of non-native plants that outcompete native plants.


If attendance were the sole measure of success, the conference was a resounding success.  The conference was sold out with record-breaking attendance of 1,200 people.  That’s a 50% increase in attendance since 2018, when 800 people attended.  People came to learn about the many opportunities for public funding of their “restoration” projects and they were not disappointed.

Jennifer Norris, Deputy Secretary for Biodiversity and Habitat for the California Natural Resources Agency (CNRA) was one of the keynote speakers.  She and many other staff of CNRA made presentations at the conference to inform the community of native plant advocates about the many new opportunities to obtain grants for their projects.  This slide (below) shown at the conference, itemized by state agencies the $1.631 Billion budget for just the 30 X 30 portion of the CNRA’s environmental grant programs.  It does not include Cal-Fire funding for forestry projects to reduce wildfire hazards and address climate change.  Nor does it include $10 million of new funding for Weed Management Areas, which funds projects that attempt to eradicate non-native plants and $10 million of new funding for the state council for invasive species. State funding is also supplemented by new federal funding in support of a national goal of achieving 30 X 30. 

But money isn’t the only element of this state program that native plant advocates are excited about.  They have also been gifted a three-year moratorium on requirements for Environmental Impact Reports for their projects.  There will therefore be no requirements for a public process to review plans and comment on them. 

An anxious applicant for state grant funding asked a speaker representing the Wildlife Conservation Board about a rumor that projects using herbicides would not be funded.  The speaker’s reassuring answer was, “We are not rejecting projects using herbicides.” Applicants are being asked to complete a questionnaire about herbicides they plan to use, but the speaker was quick to add, “We have not rejected any [such applications] so far.”  She assured the audience that “You are all careful” in your use of herbicides.

Huge buckets of money are being distributed with no restrictions on the use of herbicides and no vetting process such as an environmental impact review with opportunities for the public to comment.  It seems inevitable that some of the projects will unintentionally do more harm than good, and the public will have nothing to say about which projects are funded. 


Alexii Sigona was the first keynote speaker for the conference.  He is a member of the Amah Mutsun-Ohlone Tribal Band (not a federally recognized tribe) and a Ph.D. candidate at UC Berkeley in the Department of Environmental Science.  He explained that there are 600 recognized members of the Amah Mutsun Band in a wide region around Pescadero, Hollister, and San Juan Bautista.  They collaborate with organizations such as CNPS because they don’t have the resources to manage their ancestral tribal lands.  He described some of the projects they engage in:

  • Landscape scale removal of “invasive” plants.
  • Plug planting of 120,000 native grass plants.
  • Creating “native hedgerows” for food sources.
  • Removal of native Douglas Firs “encroaching” on grassland.  They have removed 5,000 native Douglas fir trees.  He acknowledged that this project caused some concern about erosion and aesthetics.  Removal of native Douglas fir was mentioned by several other speakers during the conference.  It is an example of the preference of native plant advocates for grassland because it is the pre-settlement vegetation.  Native coyote brush is another target of eradication projects that attempt to prevent natural succession of grassland to other vegetation types. 

There is great interest among native plant advocates in the land management practices of Native Americans because controlled burns were Native Americans’ most important tool to maintain grassland species needed for food and for their prey.  Controlled burns are important to native plant advocates because they believe they are beneficial to native plants and help to control non-native plants.  Prescribed burns are also currently popular with many public land managers and they are the current fad among many fire scientists. 

Two presentations at the conference suggest that prescribed burns are not compatible with the preservation of native chaparral, nor are they capable of converting non-native grassland to native grassland.

This (above) is the concluding slide of Jon E. Keeley’s presentation.  Dr. Keeley is a respected fire scientist with US Geological Service with expertise in chaparral species.  He explained that 60% of native chaparral species (notably manzanita and ceanothus) are obligate seeders that do not resprout after fire and therefore depend on the existence of their dormant seed bank for regeneration.  In recent decades the fire interval in chaparral has decreased due to climate change and associated drought.  In many places, the fire interval has become too short to establish the seed bank needed for regeneration.  In those places Dr. Keeley has observed vegetation type conversion to non-native annual grasses. 

Dr. Keeley Is concerned that vegetation type conversion from forests in some cases and shrublands in others to non-native annual grassland may be the result of shortening fire intervals further “because of the upsurge in state and federal programs to utilize prescription burning to reduce fire hazard.” (1) This concern extends to some conifer species that do not resprout.  Some are serotinous conifers whose cones are sealed shut and do not release their seeds in the absence of fire. 

This is a familiar theme for much of Dr. Keeley’s research.  He asks that land managers balance the conflicting goals of resource management and fire hazard reduction. 

This (above) is the concluding slide (sorry for the poor quality of my photo) of a presentation about a 20-year effort at the Santa Rosa Plateau Ecological Reserve to convert non-native annual grassland to native grassland, using annual (sometimes bi-annual) prescribed burns.  Many different methods were used, varying timing, intensity, etc.  The abstract for this presentation reports failure of the 20-year effort:  “Non-native grass cover significantly decreased after prescribed fire but recovered to pre-fire cover or higher one year after fire.  Native grass cover decreased after prescribed fire then recovered to pre-burn levels within five years, but never increased over time.  The response of native grass to fire (wild and prescribed) was different across time and within management units, but overall native grass declined.” (1)

The audience was audibly unhappy with this presentation.  One person asked if the speaker was aware of other places where non-native grass was successfully converted to native grass.  The speaker chuckled and emphatically said, “NO.  I am not aware of any place where native grasses were successfully reintroduced.” 

Another questioner prefaced her question with the admission that “I’m new here and all this is new to me.”  Then she suggested that Native Americans are having some success using prescribed fire and that they should be consulted.  The speaker graciously replied that she planned to do so. 

Keep in mind that Native Americans weren’t historically using prescribed fire to convert annual grasses to native grasses.  Their burns were intended to maintain native grassland in the absence of competing non-native annual grassland.  Their objectives were different and they were operating in a very different climate and environment. 

Estimates of the pre-settlement population of Native Americans in California range from 138,000 to 750,000.  The population of Native Americans is estimated to have been reduced to as few as 25,000 after the arrival of Europeans due to disease and violence.  There are now over 39 million Californians and only 630,000 of them were Native Americans in the 2020 census.  Land management practices that are suitable for a population of less than 1 million seasonally migrating Californians are not necessarily suitable for a population of over 39 million sedentary Californians.   

The futility of trying to eradicate non-native plants

The Invasive Spartina Project (ISP) is another 20-year eradication project that is doomed to failure.  The presentation about the ISP was bravely made by Dr. Debra Ayres, one of the creators of the ISP in 1998.  With intensive effort and hundreds of gallons of herbicide (imazapyr), non-native spartina marsh grass has been greatly reduced in the San Francisco Bay, but the hybrid of non-native S. alterniflora and native S. foliosa persists.  Dr. Ayres explained why:

The spartina hybrid is reproductively stronger in every way than either of its parent species.  Dr. Ayres predicts that the hybrid will eventually replace both of its parent species:

If the goal of this project was to eradicate non-native spartina, hybrid spartina will accomplish that goal. You might think that this prediction would end the futile attempt to eradicate the hybrid, but you would be wrong.  There is no intention of abandoning this 20-year project.  More funding is assured by the California Coastal Conservancy and the project continues to provide well-paid jobs. 

Dr. Ayres ended her presentation with this enigmatic statement:  Evolution doesn’t stop just because we think it has to.”  She seems to acknowledge that humans cannot stop evolution, yet she seems to recommend that we continue to try doing so.  If those positions seem contradictory, that’s because they are.  The bottom line is that as long as public funding continues to be available, this project will continue.

A central theme of the nativist agenda is the futile desire to prevent hybridization because it has the potential to replace a species considered “native.”  They fail to understand that hybridization is an important evolutionary tool that helps plant and animal species adapt to changes in environmental conditions by favoring traits that are better adapted to new conditions.  Humans cannot stop evolution, nor should we try.

San Francisco

I have a special interest in San Francisco because I lived there for nearly 30 years.  The native plant movement is very strong in San Francisco and there were several presentations about the success of the movement at the conference.

Sunset Blvd being built on barren sand in 1931

One of the projects is trying to turn Sunset Blvd on the western side of San Francisco into a native plant garden.  I lived in that district and am therefore familiar with Sunset Blvd as the major north-south traffic artery through the district.  It is important as the only wind break in the windiest district of the city, which is only 13 short blocks from the ocean.  The district is virtually treeless because of wind conditions and the pre-settlement landscape of barren sand.  Sunset Blvd is therefore the oasis of the Sunset District.  In the past, it was the only place to take a long walk in the shelter of the tall Monterey pines and cypress and tall-shrub understory.  The lawn beneath the trees was the only place for children to play close to their homes.

San Francisco’s Department of Public Works (DPW) is responsible for maintaining the medians in San Francisco.  It was therefore DPW’s responsibility to replace the wind break on Sunset Blvd that is dying of old age.  That’s not what they chose to do.  They are replacing the lawn with native shrubs and the tall trees with small native trees that won’t provide shelter from the wind. 

The spokesperson for DPW acknowledged that the project is controversial.  Neighbors of Sunset Blvd valued the sheltered recreational space provided by the 2.5 mile-long and wide median.  Native plant advocates and their allies want to create a wildlife corridor through the western edge of the city.  The spokesperson for DPW said that their plans are a compromise between these different viewpoints.  I don’t know if the neighbors agree, but I can say that native plant advocates are thrilled with the new native plant gardens on Sunset Blvd based on their presentation at the CNPS conference.

Planting Sunset Blvd. with native plants, December 2020

Native plant advocates prevailed on Sunset Blvd because CNPS bought or raised all the native plants and provided volunteers to plant them and maintain them for 3 years.  DPW couldn’t look their gift horse in the mouth. DPW hired 6 new gardeners to support maintenance of Sunset Blvd. This is an example of how the money that is flowing into such projects will transform many places into native plant gardens. 

Sunset Blvd and Taraval, spring 2022

So, let’s look at the result of these projects.  Presenters of these projects showed many beautiful pictures of newly planted native gardens on Sunset Blvd (above).  The pictures were taken in spring, when native plants briefly flower.  But that’s not what these places look like most of the year.  They will look better if they are irrigated year-round, but that would defeat the purpose of replacing the lawn to reduce water usage.  Unlike native plants, lawn turns brown during the dry season if it isn’t watered, but it is still functional as walkable ground. 

Here’s what that garden at Sunset Blvd and Taraval looks like most of the year:

Sunset Blvd & Taraval, October 23, 2022

There was also a presentation by a spokesperson from San Francisco’s Public Utilities Commission (PUC) about the creation of rain gardens in San Francisco.  San Francisco’s sewer system was built long ago when regulations did not require the separation of street run off from residential sewage.  When it rains, the sewage treatment plant is overwhelmed by street run off.  The sewage treatment plant releases untreated sewage and run off into the ocean, in violation of federal standards for water treatment. 

Rain garden on Sunset Blvd as shown at the CNPS Conference
Rain Garden on Sunset Blvd in August 2022. They aren’t pretty year around.

The PUC is developing rain gardens to redirect street run off away from sewage treatment plants into the ground so that treatment plants are not overwhelmed during heavy rain.  The San Francisco Chronicle recently reported that 151 rain gardens have been installed so far. It seems a very good idea, but native plant advocates are not happy with the rain gardens because the PUC has not made a commitment to plant exclusively native plants in the rain gardens.  The audience pressured the speaker about this issue.  He advised them to lobby the PUC to make a commitment to plant only native plants in the rain gardens.  I have no doubt that they will take his advice.  Given their influence and their access to public funding, I would be surprised if the PUC continues to resist their demands.


I have undoubtedly exhausted your patience, although there is much more I could tell you about, including several projects that look promising because they are exploring the importance of soil health to achieve successful results.

The conference themes in 2022 were consistent with the previous two conferences I have attended since 2015.  This is my summary of the fundamental errors of the nativist agenda in the natural world.  They are as apparent in 2022 as they were in 2015: 

  • The futility of trying to eradicate non-native plants that are better adapted to current environmental conditions.
  • The futile and harmful attempts to prevent natural succession and hybridization.
  • The contradictory goals of fuels management and resource management.
  • The lack of understanding that vegetation changes when the climate changes.  The ranges of native plants have changed and will continue to change.  The pre-settlement landscape of the 18th century cannot be recreated.
  • The lack of understanding of the importance of soil health to ecological restoration and associated ignorance (or denial) of the damage that pesticides do to the soil. 

(1) Abstracts for all presentations are available on the CNPS website.