My transition from activist to observer

This is my last article of 2024, and the last for the foreseeable future.  However, I still welcome guest posts that are consistent with the mission of my website.  If you have a story to tell, please contact me at mildredtrees@gmail.com.

Clarification:  I published this article prematurely on November 28th in error.  I republish the article today to clarify my intentions.

Although I have accomplished little in 25 years of environmental activism, I can point to a few achievements that I am proud of. 

  • I was successful in getting the “invasiveness” of eucalyptus downgraded from “Moderate” to “Limited” by the California Invasive Plant Council.  There were a few specific issues that were deleted from Cal-IPC’s assessment of eucalyptus.  The assessment no longer claims that eucalyptus kills birds.  Cal-IPC also removed the claim that eucalyptus leaves are allelopathic, i.e., they do not emit a chemical that suppresses the growth of an understory.  However, these improvements in Cal-IPC’s assessment of eucalyptus had no apparent effect on the demands of native plant advocates to destroy all eucalyptus in California.
  • I am proudest of our achievements to improve pesticide applications by the supplier of our drinking water in the East Bay, EBMUD.  With the help of a video and a photo, a small team of collaborators convinced the leadership of EBMUD that their staff did not know how to apply herbicides.  The leadership of EBMUD deserves equal credit for this accomplishment because they listened and they acted.  EBMUD is now conducting annual training of its staff about proper application of pesticides, herbicide application notices are being posted, and an annual report of pesticide use is presented to the Board and posted on-line for the public to see.  As a result of these efforts, herbicide applications were reduced by one-third, but have since plateaued. 
  • When the SelecTree website published by CalPoly San Louis Obispo claimed that blue gum eucalyptus lives only 50 years, it became another tool nativists used to support their demands to destroy blue gums in California.  I was able to give CalPoly the evidence needed to disprove this inaccurate claim.  Blue gums have lived in California since the 1860s and many of the original plantations are still alive.  Eucalypts are known to live in Australia from 200-400 years.  It’s difficult to determine the age of eucalyptus because trees growing in mild climates such as ours do not have clear growth rings used to determine age.  SelecTree initially changed the lifespan estimate to 150 years, which was the maximum lifespan for the entire SelecTree database of trees in California.  Since then, SelecTree has deleted all lifespan estimates because they weren’t able to find reliable sources of this information.  The correction of blue gum lifespan on SelecTree relieved some of the pressure to destroy them. 
  • I also claim small credit for the final version of Oakland’s Vegetation Management Plan, which is a compromise with native plant advocates who wanted all non-native trees on public land in Oakland to be destroyed and replaced with native trees.  The consultant who wrote the plan also deserves credit for listening and reading studies I sent to him about the flammability of trees.  Non-native plants and trees are not inherently more flammable than native trees. We live in a Mediterranean climate in which vegetation is fire adapted and fire dependent.  It took 7 years and 4 revisions to reach a compromise that satisfied the nativists.  The plan will destroy all eucalyptus less than 31” in circumference on 2,000 acres of public land and 300 miles of roadside.  The plan will also use herbicides on public land where it has been prohibited since 1998, when herbicide spraying was confined to road medians.  Although the plan is destructive, its approval after 7 years of pointless delay will finally enable Oakland to mitigate fire hazards with fuels reduction without destroying all non-native trees on public land.

These were small victories and they were difficult to accomplish. I won’t bore you with a list of hundreds of my failed efforts to protect public lands from needless destruction.  My most recent failure was an appeal to California’s Wildlife Conservation Board, which is theoretically responsible for protecting California’s wildlife. Despite the effort of a small team of collaborators, the WCB granted another 10 years of funding for an eradication project that has killed over 50% of an endangered bird species in the San Francisco Bay after 20 years of spraying herbicides, destroying the bird’s habitat and its food. 

I hope these few achievements and multitudes of failures will help to convey why I am pulling back from my 25-year effort to defend our urban forest and our public lands.  In a word, it is unrewarding work.

Good sources of information about invasion biology and the “restoration” industry

I have 535 subscribers on Conservation Sense and Nonsense and over 1,000 followers on Meta (Facebook).  In addition, my articles on Conservation Sense and Nonsense have been read by over 500,000 people who found them with internet searches over the 15 years that Conservation Sense and Nonsense has existed. 

I intend to keep posting occasional news items to Facebook and I welcome my readers to follow me there.  I also encourage my readers to follow other sources of reliable information about the issues I have covered.  I leave the field in the good hands of those who still have the courage to fight what seems like a losing battle:

  • Beyond Pesticides is a reliable source of information about pesticides.  I recommend that you subscribe to BP’s Action Alerts that inform us of opportunities to engage with decision makers about new policy decisions regarding pesticides. 
  • For home gardeners looking for advice about creating gardens that are beautiful as well as respectful of the environment and the animals that live in our gardens, I recommend that you subscribe to Garden Rant.
  • For readers who love all plants, both native and non-native, I recommend the Substack of Kollibri terre Sonnenblume.  His articles are deeply researched, informative, and beautifully written.  His knowledge of plants far exceeds anything I have learned about plants because he works directly with them as an integral part of his life and he is an astute observer.

Right turn at the crossroads

After a long, bumpy trip to the crossroads of the 2024 presidential election, the American people made a hard right turn on Election Day.  Voters have re-elected President-elect Donald Trump and given him control of all branches of government with which to implement his agenda. 

As Trump approached the crossroads he also acquired some allies who will be influential in crafting his agenda.  Wunderkind Elon Musk, who is already a major government contractor in space exploration and telecommunications, is likely to influence and benefit from policies in those—and other—areas. Billionaire “tech-bros” have convinced Trump to promote crypto currency.  Robert F. Kennedy, Jr. is likely to influence the future of our policies regarding health, such as the availability of drugs and vaccines. 

This is to say that although we can’t predict specific policy decisions, we can predict that there will be significant changes in the functioning of the federal government.  We know that Republicans have been trying for years to defund, if not eliminate, many federal agencies.  

The Environmental Protection Agency and the Department of the Interior have long been Republican targets for budget cuts.  And the US Supreme Court has collaborated with this effort by reducing the power of federal agencies to implement policies that aren’t specifically authorized by federal laws.

We should probably expect that federal funding for many so-called “restoration” projects will evaporate, such as the USFWS plan to shoot 500,000 barred owls in Western Forests or the USFWS plan to dump rodenticides on hundreds of off-shore islands to kill non-native animals.  Likewise, the theoretical ability of the EPA to evaluate new pesticides for access to the market is likely to end altogether, to the extent that regulation exists at all.

On the other hand, State funding of “restoration” projects is unlikely to decrease.  California voters have approved Proposition 4, which will provide $10 billion of bonds for water, wildfire, and land protection in California.  The federal government is expected to withdraw funding for ecological “restoration” while California state government is likely to replace the lost federal funding.

Becoming an observer

We are headed into a long period of radical change.  It is an opportunity to hunker down and watch the changes play out. That is my plan for the foreseeable future.

Although environmentalism had little explicit role in the rightward shift in American politics, it probably played a role on the margins.  The electorate’s rejection of environmentalism as a priority policy goal requires some deep reflection. 

Does environmentalism contribute to the political divide between urban and rural voters?

  • For example, urban environmentalists support the reintroduction of top predators, such as wolves, into rural communities, where they become predators of domesticated animals.  Rural communities resent that their livelihoods are threatened by decisions made by urban policy makers who are not impacted by the decisions they make. 
  • Proposition J in Sonoma County would have shut down many agricultural operations that raise animals.  Most of these agricultural operations are certified organic and they are central to the economy of Sonoma’s rural community. Proposition J was easily defeated by an agricultural community that could have been destroyed by an extremist version of environmentalism.  However, a similar Proposition DD in Berkeley passed narrowly in a community with a more diverse economy. 

Has environmentalism contributed to the high cost of housing and the growing homeless population?

  • The San Francisco Bay Area Chapter of the Sierra Club has a track record of suing to prevent the building of new housing.  The Chapter’s support for this agenda reflected the opinions of entrenched elected leaders who were recently displaced by a coalition of housing advocates.  One of the displaced leaders explained how this coup has changed the Chapter’s approach to new housing.  The changed leadership is now reflected in the Chapter’s political endorsements of housing advocates, such as State Senator Scott Wiener.
  • The insurance industry in California is in trouble.  Major insurance companies have left California.  Some have quit insuring homes.  The companies that remain have cancelled thousands of policies insuring homes. Premiums of the policies that remain have increased significantly and are expected to increase further.  California’s wildfires have increased the costs of the insurance industry and California has not allowed the insurance industry to anticipate increased risks of wildlife in setting premium prices for home insurance.  Insurance is required to finance new building and home buyers cannot get a mortgage without property insurance.  The 7-year delay of Oakland’s Vegetation Management Plan is an example of how extreme versions of environmentalism have handicapped fire hazard mitigation. 

Statement of Purpose

I am a moderate Democrat who voted for the Democratic candidate for president in 2024.  I am disturbed by the sudden and extreme lurch to the political right.  I also see it as an opportunity for all Americans to think deeply about how we reached this point.  I intend to do more listening and less talking.  I hope to find something more rewarding to do. 

I leave the field knowing that nativism in the natural world will be defeated eventually by evolution, as natural selection “chooses” the plants and animals capable of surviving in a radically altered climate.  Nativism in the natural world is ultimately a dead end.  Nature moves forward, not backward.  Activism, such as mine, will not successfully deliver that message to the ideologues who continue to destroy the plants and animals most likely to survive, but nature will, because nature always bats last. 

Thank you for your readership.  Best wishes for happy holidays and a more peaceful new year in 2025.

Invasion Biology: “We can do whatever we want”

Macaylla Silver discovered Conservation Sense and Nonsense on Facebook.  We instantly recognized one another as kindred spirits, battle scarred by our attempts to protect nature from pointless destruction in service of the ideology of invasion biology and the native plant movement it spawned. 

When confronted with the destruction of wild places we love, our reaction was very similar, and responses to our efforts were also similar.  First we turned to public policy for protection:  Are they really allowed to poison our public lands with pesticides to destroy harmless plants? With a few targeted “exceptions” to policy, the answer was always, “We can do whatever we want.”

Then we both decided the best course of action was to become experts about the “science” that is used to justify destroying harmless vegetation with herbicides.  And so, we took to the books and armed ourselves with the science that refutes invasion biology.  Once again, we hit the brick wall of “We can do whatever we want.”

And there Macaylla’s experience as an activist diverges with mine.  He has successfully stopped the poisoning of Leverett Pond (for the time being) by showing the neighbors of Leverett Pond with videos, the consequences of poisoning the pond. 

However, he concludes his story with the astute observation that stopping the destruction of Leverett Pond is unlikely to be the end of the story.  Life in the pond will continue to evolve, as it must.  As long as people continue to believe that evolution must be stopped, the futile attempt to prevent change will continue. Macaylla is hopeful that mistaken belief will fade.  I hope he is right.

We thank Macaylla for his efforts.  We wish him luck in preventing more herbicide applications in Leverett Pond.

Conservation Sense and Nonsense


“Let the Pond Be a Pond”

Massachusetts Wetlands Protection Act was created for the protection of the state’s wetlands. The goals of the law are to prevent pollution, maintain habitats for plants and wildlife, and protect groundwater, public and private water supplies.

Our Town Bylaws in Leverett, Massachusetts also included a ban on the use of herbicides for any use outside of domestic and agricultural use since 1973.

There are five colleges in the area. The town is filled with highly educated academics and retired academics. Leverett is quite ecologically minded in my opinion, this hill town of 2,000 people.

Leverett Pond, circa 1860-1880, Erastus Salisbury Field.  Public domain.

One day back in 2018, I found that the large body of water at the town’s center, Leverett Pond, was under ecological attack. Somehow, some way, a handful of land abutters on the shallow side of the pond were trying to rid the pond of “noxious weeds.”  This included floating leaved Waterlilies and Watershield, plants such as rootless carnivorous plants like Bladderworts, submerged weeds like Coontail, Waterweed and Milfoils.  Even Cattails and other plants growing on the pond’s edges were considered for removal.

Act One:  Isn’t there a law against this?


I thought I could stop this. I thought once the town’s people knew what was happening they would be outraged. I thought the state would step in, prevent the further destruction and maybe even fine the people who were poisoning the area and dredging large sections, all so they could in their words “have crystal clear water to look at.”

I thought it would be easy.  I have never been so wrong in my life. 

It was five years of continual meetings, letter writing, publishing newspaper letters and articles, and a large portion of the town thinking that somehow I was just trying to cause trouble. Or maybe they didn’t think I knew what I was talking about. Sure, I saw the destruction, but I was misinformed. They believed in their intent and factual details of why they were on a campaign of eradication.

The details of destruction used to convince the town’s Conservation Commission, Select Board, and state agencies came from two retired professors, neither with a degree in Environmental Ecology. Their plan contained the curveball of being designed to show off knowledge of several obscure subjects unknown to nearly everyone:

1.Limnology: The science of fresh water systems
2.Pesticides and their application to aquatic environments
3.The botany and identification of aquatic plants

Act Two:  Countering Pseudoscience with Science


While the wordsmithing of the two PHDs had merit and flow, my own research quickly showed that they had only a surface understanding of subjects.  In order to counter their statements and proposals, I decided that I would deeply learn all I could about limnology, pesticides and the life of aquatic plants. I would become an expert, the old fashion way: I would purchase books. Lots of them. I read extensive science based articles on pesticide families, collecting hard data and staying away from anything that was too opinionated. 

People began to realize that I knew more than expected, so much more that it was easy to forget that the vocabulary was rarely understood. I presented myself on equal footing with proponents of the project.  I asked the community and its policy makers to consider that dumping herbicide on the pond might not be the best thing, creating aporia, lingering doubts that this handful of lakefront owners may have hidden motives.

Act Three:  Invasion Biology at Work

Then came the videos. I purchased two kayaks, an underwater camera, and I used cameras I had purchased for bird photography. The videos contrasted the “before and after” of the years of degradation in 2019, 2020 and 2022. The videos got the state involved.   The state permits for dredging that the project applied for in 2010 were never received. This meant that the project had to reapply for permits for any further work after 2020. 

Up to this point, I thought I was fighting against ignorance and arrogance from a few landowners who came late to the pond’s available real estate and bought lots that were undesirable because of their shallowness and large amounts of aquatic flora and fauna. I would have been in heaven if I bought such an area, but they looked to “improve it.”  So they had set out to “manage” the water’s surface.

The two professors contacted a professional who specialized in finding ways around what was allowed by the Wetlands Protection Act. Leverett’s Conservation Commission reviewed the law and found that there were no ways around the law because the plant abundance, oxygen levels and fish life were all healthy, vibrant. Graphs, data, reams of older regurgitated documentation pointed to the same conclusion I had reached: Let the pond be a pond.

To show the reason why no further “management” permits would be issued to continue the project, the head of the Conservation Commission submitted his own reason: the project violated Town Bylaws. Clearly. 

Then it happened. Three members of the Conservation Commission had what I thought were very strange ideas about conservation.  One had a pesticide license. One looked at the pond for recreation purposes rather than an interest in environmental issues. Another felt strongly about eradicating plants that they couldn’t identify if asked.  One said, in defense of using pesticides, the blithe motto “If you can choose it, you can use it,” while the other two nodded in agreement. “We have to stop the growth of these plants before they destroy the pond. It will reach a tipping point where there will be no return,” said one, with great conviction.  “It could in the future make the fishery less healthy,” said another, without a shred of data.  I had no idea why such people would be put on such a Commission. 

The Conservation Commission voted three to two to allow the project to continue for another five years. The state admonished but did not intervene. I had been angry at the professors and their allies for their lack of concern. Now the Conservation Commission had let me, and the pond, down.

The decision of the Conservation Commission gave the pond abutters cover, so they could remove all the plants they wanted. The Commission gave herbicide sprayers a welcome mat in Leverett to earn big money for the applicators and companies that make a variety of toxins.

The decision gave the Conservation Commission, not its local intended use, protecting wetlands and freshwater, but a zealous conviction that they were acting on a world saving mission.  It was Invasion Biology at work, masquerading as “restoration,” AKA the “native plant movement.” Invaders needed to be destroyed, regardless of recklessness, collateral damage, complete destruction.

So destroying acres of plant life, to get at one plant, that is okay now.  They were Crusaders with a capital “C.” And like all crusades…it rarely ends well.

Act Four:  Pictures are worth thousands of words

In 2022, the herbicide sprayers came back, on a very windy day, on an airboat. It appeared that the targeted areas were being sprayed, yet large amounts were misted and blowing in the air as the airboat itself churned the water’s surface. It was, in a word, sloppy.

From my kayak, I videoed the spraying of the pond with herbicides from an air boat: the before, during, and the after of floating masses of dead vegetation. I got the resulting video shown to many. It had few words, an eerie soundtrack that suited the unreal transformation, from living beauty to full degradation, death and decay.  (see below)

Leverett Pond after herbicide spraying in 2022. Entire video available HERE.

For the next year, and the next they stopped spraying. Sure, they hired an aquatic harvester to clean around the area of their docks, but that was it.

In 2024, the promoters of the deadly project were apologetic. They promised that “no herbicides” would be used. Even an attempt to hand pull marginal plants failed.

The pond will continue to respond to changing climate conditions, as it must.  Plants are likely to return and the fear-mongers are likely to demand their destruction again.

Fear of so-called “invasive species” is being used as an excuse to use herbicides in the futile attempt to freeze ecosystems that replicate historical landscapes.  As climate conditions continue to change, the fantasy that humans can prevent evolution is likely to fade.   Perhaps the restoration movement will begin to realize the folly of trying to sort plants and animals into two simplistic groups:  native vs. non-native.

As Charles Mackay said in a book written in 1841, ” Men, it is said, think in herds; it will be seen that they go mad in herds, while they only recover their senses slowly, one by one.”

Macaylla Silver
Leverett, Massachusetts
Contact:  artargentia@gmail.com

Nature’s Best Hope? Nope!

On November 16, 2024 I attended a conference at the Oakland Museum of California, where I live, sponsored by Bringing Back the Natives Garden Tour and featuring Doug Tallamy as the key note speaker.  The conference was sold out.  Two hundred enthusiastic native plant gardeners attended the conference.  Although a native Coast Live Oak is the crown jewel in my garden, I don’t consider myself a native plant advocate.  I listened quietly.

I have heard Doug Tallamy speak several times and I have read his books, so there were few surprises in his talk, except for this slide:

The cited study for this slide was published by Matthew Forister (and others).  Professor Forister is an academic entomologist who is a specialist in lepidoptera (moths and butterflies).  I have read several of Forister’s studies and I respect his research, so I was surprised that he would reach the conclusion claimed on Tallamy’s slide. 

I read the study (available HERE) and I was unable to find a conclusion in the study that was consistent with Tallamy’s interpretation of it.  Hmmmm, I said to myself, does Tallamy’s slide accurately represent Forister’s study? 

I asked Claude.ai to compare the study with Tallamy’s brief summary of the study.  Claude’s response was: 

“After carefully reviewing both the original study and Professor Tallamy’s summary slide, I find that his statement represents a somewhat oversimplified interpretation of the study’s findings…While Professor Tallamy’s statement captures the general spirit of the research – that most insect herbivores are specialists – it appears to be a simplified interpretation that makes stronger and more specific claims than what’s directly supported by the study’s data. The “90%” figure and the explicit connection to evolutionary history, while perhaps derived from other research, aren’t directly demonstrated in this particular study.”

Forister’s study found a continuous distribution between specialists and generalists, not a strict dichotomy, as Tallamy’s slide claims.  For example, an insect that is confined to plants in a genus is more specialized than an insect that is confined to a plant family.  Insects that are confined to a single plant species are extremely rare because they are often an evolutionary dead end. 

Professor Forister’s study is interesting.  It found that dietary specialization of insects varies by latitude and that specialization is greatest near the equator, where diversity of plant species is greatest, creating more opportunities for ecological niches in which specialized insects can find what they need with less competition.   

The same principle applies in the temperate zone, where we live.  That is, greater diversity creates more opportunities for insects to find what they need.  The scientific definition of biodiversity includes both native and non-native species.

The relationship between plant species in the Apiaceae family and the anise swallowtail butterfly evolved in the distant past, eons before individual members of the family evolved into different genera and species.  The association between an insect and its host plant is chemical rather than being a connection to a specific plant species.  In other words, anise swallowtail butterflies co-evolved with fennel. 

Likewise, monarch butterflies co-evolved with tropical milkweed, which is native to Mexico and Central America.  Both tropical milkweed and local native plants in the same genus contain the chemical that monarchs seek, a chemical that renders it unappealing to its predators because it makes them sick.  Again, this similarity is fortunate because tropical milkweed is evergreen and local natives are deciduous, making it available for monarchs to breed in winter months in a warming climate. Winter breeding of monarchs is recent and may not benefit the monarch population because fewer food sources are available in winter months. (2)

With the help of genetics, we can understand why individual members of a family of plants are closely related.  Plants and animals with a common ancestor are dispersed around the globe in a variety of ways, of which many are natural and long precede the advent of humans around 300,000 years ago.  Plants are carried by ocean currents, rivers, wind, storms, birds, animals, etc. 

When plants arrive in a new home, they quickly begin to change, partly because of random genetic drift and partly because they respond and adapt to the specific environment in which they have landed.  Over time, the change in the plant becomes great enough to be considered a new species, but its chemical properties remain similar to its ancestors in most cases.  Exceptions abound because nature is complex and our understanding is limited.

Why does it matter?

I attended this conference because native plant advocates are unhappy about Oakland’s Urban Forest Plan.  I support the plan because it will improve Oakland’s urban forest by addressing hazardous tree conditions, expanding the forest with diverse tree species, and more equitably distributing Oakland’s forest resources to neighborhoods that have been short-changed in the past.  I expected the plan to be discussed at the conference.  It was.

Native plant advocates want Oakland to plant more native trees and fewer non-native trees.  Opinions vary, of course, but some want a forest of exclusively native trees because of their belief that native trees support wildlife and non-native trees are not useful to wildlife.  There are many reasons why a diverse urban forest best serves Oakland and every animal that lives here:

  • The pre-settlement vegetation of Oakland was 98% grass, shrub, and marshland.(1) There were only 10 species of trees that are native to Oakland:  coast live oak, bay laurel, coast redwood, madrone, big leaf maple, holly leaf cherry, toyon, willow, buckeye, redbud.  There are now over 500 tree species in Oakland.
  • The goal of the Urban Forest Plan is to increase the population of street trees.  Most of the trees that are native to Oakland are not suitable as street trees.  Some are too big.  Some are shrubs rather than trees.  The branching habit of some native trees are too low to be street trees, which must not obstruct sidewalks or streets. 
  • Some shrubs can be pruned into trees, but that would be very costly and Oakland is broke!  A shrub that has been severely pruned into a tree is not stable.
  • Growing conditions where trees are needed in Oakland are often not suitable for native trees. That’s why they didn’t grow there prior to settlement.  Oakland’s urban forest is predominantly non-native because they are adapted to our growing conditions.
  • Climate change requires a diverse urban forest because a more diverse forest is more resilient.  Sudden Oak Death has killed millions of oaks throughout California for the past 25 years. We can’t predict which tree species will survive the warming climate.  Therefore, we must hedge our bets by planting a diverse forest.

As expected, the first question the audience asked of Doug Tallamy was why Oakland Tree Services is telling native plant advocates that Oakland can’t plant exclusively native trees because they aren’t adapted to the challenging conditions that street trees face.  Doug Tallamy replied that Oakland’s Tree Services is mistaken.  He showed this slide of the many native alternatives that he believed would be suitable street trees:

This list is predominantly shrubs.  Some are not native to Oakland.  Some plants native to Oakland are missing from the list. At least one—Himalayan blackberry—is a notorious invasive non-native that most public land managers have been trying to eradicate for decades.  Himalayan blackberry is, however, an extremely useful plant for wildlife.  The list is a mixed bag, but it won’t create an urban forest.  

Update:  The Public Works & Transportation Committee of the City of Oakland approved the Urban Forest Plan for Oakland today, December 10, 2024.  Eleven people spoke in support of the plan.  No one spoke against the plan.  

Dan Kalb, City Council representative for District 1, asked why Oakland is planting non-native trees, which he claimed are breaking sidewalks and destroying the foundations of people’s homes by sending their roots into their yards.  David Moore, the head of Tree Services, handled these questions well and Kalb did not pursue the issue further. No speaker objected to non-native trees in Oakland.  

I have a native Coast Live Oak in my front yard, which damaged the foundation of my home, destabilizing the house and doing extensive damage inside the house.  To save the tree, we had to repair the foundation by suspending the new foundation over the roots from two steel-reinforced piers that are 10 feet deep at each end of the foundation.  In other words, although there is some variation in the configuration of tree roots, the variation is unrelated to the national origin of the tree species. 

Given the budget deficit in Oakland, it was necessary to reduce the goal of the plan to maintain the tree canopy rather than increase it.  No one objected to that change in the goal.  We all understood that the change was necessary.

On the bright side

I enjoyed two presentations by native plant gardeners who transformed their yards from barren places into lovely native plant gardens.  One started her project by digging up concrete covering her back yard.  The other began by digging up a front lawn.  Of course, their new gardens are an improvement over their predecessors.  They are more beautiful and they serve more wildlife. 

However, would these new gardens be even more beautiful and useful to wildlife if they were more diverse?  Would they be more resilient as the climate continues to change in unpredictable ways?  Maybe.

Thankfully, there was little talk of destruction in either of these inspiring presentations.  One exception was an anecdote about the visit of a native plant advocate to the garden of a fellow gardener.  The gardener asked his visitor where agapanthus in his garden is from.  When told it was from South Africa, he promptly pulled it out of the ground. The audience was very amused by the story.

When traveling in distant places, I don’t want to know which plants are native.  Don’t ask, don’t tell.  It’s a pleasant break from the “good” plant, “bad” plant dichotomy. 

Tallamy advised against using insecticide, but he made no mention of using herbicides. 

I have no quarrel with these gardeners.  I firmly believe that everyone should be free to plant whatever they wish in their gardens.  I respect everyone’s plant preferences and I ask that they respect mine. 

However, our public parks and open spaces belong to everyone and our tax dollars are used to maintain them.  I ask only that public land managers quit destroying healthy trees and landscapes, especially with herbicides. 


(1) David Nowak, “Historical vegetation change in Oakland and its implications for urban forest management,”  Journal of Arboriculture, September 1993

(2) Professor Emeritus Arthur Shapiro sent the following “qualifiers” in an email.  The article has been revised accordingly.  “…a couple of qualifiers. First, zelicaon cannot breed all year because it has a seasonal pupal diapause (dormancy) in winter which is photoperiod—T mediated. Its native wetland hosts (Cicuta and Oenanthe) support breeding March-October. It is unclear that it had any native hosts at all in upland, dry habitats. It was probably a tule marsh species in pre-European CA (below about 4000′), just as its close relative machaon is a fenland species in the U.K. Second, monarchs didn’t breed in winter until recently, again because of photoperiod-T induced reproductive (adult) diapause. Tropical milkweed has been cultivated in CA for well over a century but was not bred on in winter, even in SoCal. I hypothesize that warming T is responsible for the change. It is NOT advantageous to breed in winter. Because curassavica is the only plant available, it gets reused over and over again and becomes contaminated with high levels of an infectious protozoan parasite that causes significant morbidity and mortality. The butterfly might be better off if it didn’t try to breed in winter.” November 21, 2024.

Defining “Success” so “Success” can be achieved

I always attend the conferences of the California Invasive Plant Council (Cal-IPC) and the California Native Plant Society because I feel obligated to understand their viewpoint so I can accurately report on the controversies of invasion biology.  Ironically, the more I learn about the native plant movement and the “restoration” industry it spawned, the less sense it makes.  The October 2024 Symposium of the California Invasive Plant Council has provided more evidence that attempts to eradicate well-established non-native landscapes and replace them with native plants are futile.

Tricks of the “restoration” trade

Every Cal-IPC Symposium has wrestled with the question of whether or not it’s possible to convert non-native grassland to native grassland. A study of 37 grassland “restorations” in coastal California addresses that question. (1)  It’s really quite simple.  All you need to do is define success as 25% native plants after “restoration” and limit post-project monitoring to 5 years or less:  “Monitoring is done ≤5 years after project-implementation, if at all, and rarely assesses the effects of management practice on project success.” 

It also helps if public land managers in charge of the projects won’t allow the academic researcher to enter the land to conduct a survey of the results.  43% of the projects that were studied were “statutory,” i.e., they were mandated by laws such as county general plans or legally required mitigation for projects elsewhere that Environmental Impact Reports determined were harmful to the environment.  30% of the managers of the statutory projects would not allow the academic researcher to survey their projects. 

It is also easier to achieve success if the project goal is downgraded mid-project as were many of the statutory projects because they weren’t able to meet the original goal.

Project managers can also reduce their risks of failure by planting a small number of native species that are particularly easy to grow:  “Ninety-two percent of restoration managers preferentially use one or more of the same seven [native] species.”  Seven projects planted only one native species. 

According to the study, the result of planting only a few hardy native plants is “biotic homogenization.”  Call it what you will, but this risk-averse strategy is inconsistent with claims that the goal of native plant restorations is to increase biodiversity. 

The study did not ask project managers about the methods they used to eradicate non-native plants or plant native plants.  The study tells us nothing about the methods that were used or whether or not some methods were more effective than others.  Since results of the projects were all very similar, should we assume that the methods that were used didn’t matter? 

The presentation of this study concluded with this happy-face slide. (see below) It looks like a cartoonish marketing ad to me:

Harmless aquatic plants being pointlessly eradicated

A USDA research ecologist stationed at UC Davis made a presentation about the most effective way to kill an aquatic plant with herbicides, but that wasn’t the message I came away with. 

Jens Beets told us about a species of aquatic plant that is native to the East and Gulf coasts of the US, but is considered a “noxious weed” in California, solely because it isn’t native.  He said the plant is considered very useful where it is native.  (see below)

Where Vallisneria americana is native, it is considered a valuable plant for habitat restoration because it is habitat for vertebrates and invertebrates and it stabilizes soil and water levels.  The canvasback duck is named for this plant species because it is preferred habitat for the native duck that is found in California during the winter.

 Vallisneria americana looks very similar to other species in the genus considered native in California.  For that reason, native species of Vallisneria have been mistakenly killed with herbicide because applicators didn’t accurately identify the target plant as native.  Jens Beets recommended that genetic tests be performed before plants in this genus are sprayed with herbicide.

This story probably sounds familiar to regular readers of Conservation Sense and Nonsense.  The story is identical to the pointless and futile effort to eradicate non-native species of Spartina marsh grass in the San Francisco Bay.  The species being eradicated in California is native to the East and Gulf coasts, where it protects the coasts from extreme storm surges and provides valuable habitat for a genus of bird that is plentiful on the East Coast, but endangered in California.  The 20-year effort to eradicate non-native Spartina has killed over 50% of the endangered bird species in the San Francisco Bay. 

Throwing good money after bad

Because the hybrid is indistinguishable from the native species of Spartina on the West Coast, 7,200 genetic tests have been performed in the past 12 years before hybrid Spartina was sprayed with herbicide. Taxpayers have spent $50 million to eradicate Spartina over 20 years.  Recently, California state grants of $6.7 million were awarded to continue the project for another 10 years.  A portion of these grants is given to the California Invasive Plant Council to administer the grants.

Plants are sprayed with herbicide because they aren’t native, not because they are harmful.  Even if the target species is needed by birds and other animals, it is still killed and animals along with it.  The target species looks the same as the native species and only genetic testing can identify it is as a non-native.  The non-native is the functional equivalent of the native.  It is only genetically different because natural selection has adapted it to the conditions of a specific location. 

Pesticide regulation in the US is a hit or miss proposition

The final session of the symposium was a carefully orchestrated apologia for herbicides, a defensive tirade that suggested Cal-IPC believes its primary tool is in jeopardy.  Two presentations were made by employees of regulatory agencies.  Their assignment was to reassure the public that pesticides are safe because they are regulated by government agencies. 

The fact that many countries have banned pesticides that are routinely used in the US does not speak well for our regulatory system.  America’s pesticide regulators rarely deny market access to new pesticides.  A recent change in policies of California’s Department of Pesticide Regulation made a commitment to the continued use of pesticides for another 25 years. 

In 1996, Congress ordered the U.S. Environmental Protection Agency (EPA) to test all pesticides, used on food, for endocrine disruption by 1999. The EPA still doesn’t do this today. Twenty-five years later, the EPA has not implemented the program, nor has it begun testing on 96% of registered pesticides.  In 2022, an organization that represents farm workers sued the EPA to conduct the legally mandated evaluation of chemicals for endocrine disruption.   The lawsuit has forced the EPA to make a commitment to conduct these evaluations of chemicals for hormone disruption.   

The Cal-IPC presenters got some badly needed push back from attendees.   One attendee informed the audience that all the testing of herbicides is bought by the manufacturers, not the regulators who don’t do any testing.  Another attendee pointed out that herbicides have not been evaluated for the damage they are doing to the soil, damage that makes it difficult to grow native plants in the dead soil.  The “pesticide regulator” agreed with those observations.

Fire safety or native plant restoration?

The Interim Deputy Director of the Laguna Canyon Foundation was the final presenter for the Symposium, speaking on a Friday afternoon at 4:30 pm, when there were less than 100 attendees left of the 690 registrants.  His presentation was about the blow back that his organization gets from the public about herbicide applications.  Criticism of herbicides escalated after a wet year that increased vegetation considered a fire hazard.  This photo (below) is an example of the visible effects of fuels management by Laguna Canyon Foundation using herbicides.

It seems likely that a fuels management project was selected for this presentation because it’s easier to justify herbicide use for fuels management than for eradicating harmless plants solely because they aren’t native. 

I recently supported Oakland’s Vegetation Management Plan that will use herbicides for the first time on 300 miles of roadsides and 2,000 acres of public parks and open space in Oakland.  Previously, herbicide applications were only allowed on medians in Oakland.  I tracked the development of the Vegetation Management Plan for 7 years through 4 revisions to avoid nativist versions of fuels management such as leaving dead thatch after herbicide applications on grassland or destroying non-native trees, while leaving highly flammable bay laurel trees behind or destroying broom, while leaving more flammable coyote brush behind.

However, using herbicides for the sole purpose of killing non-native plants is much harder to justify.  The irrational preference for native species has put us on the pesticide treadmill. Every plant species now targeted for eradication with herbicides should be re-evaluated, taking into consideration the following criteria:

  • Is it futile to attempt to eradicate a plant species that has naturalized in an ecosystem?
  • Will the attempt to eradicate the plant species do more harm than good?
  • Is the targeted plant species better adapted to current environmental and climate conditions?
  • Is the targeted non-native plant making valuable contributions to the ecosystem and its animal inhabitants?

If these questions cannot be satisfactorily answered, the bulls-eye on the targeted plant should be removed. Limiting the number of plants now being sprayed with herbicide is the only way to reduce pesticide use. If the plant isn’t a problem, there is no legitimate reason to spray it with herbicide.

Pot calls kettle black

The Cal-IPC presentation was a detailed criticism of the public’s complaints about herbicides used in their community.  The intention of the presentation was to arm herbicide applicators with defenses against the public’s complaints.  Herbicide applicators were encouraged to recognize these arguments (below) and participate in the “education” of the public about the righteousness of their task.

The presenter then showed a series of slides making specific accusations, such as these:  (see below)

Those who object to the pointless destruction of nature can also cite distortions and misrepresentations of facts (AKA lies) by those who engage in these destructive projects;

  • Nativists fabricated a myth that eucalyptus kills birds to support their demand that eucalyptus in California be destroyed.  There is no evidence that myth is true. 
  • Nativists also fabricated a myth that burning eucalyptus in the 1991 firestorm in the East Bay cast embers that started spot fires 12 miles away from the fire front.  There is no evidence that myth is true.
  • Nativists exaggerate the success of their projects by setting a low bar for success, conducting no post-project monitoring, and restricting access to their completed projects.  
  • The EPA justified the dumping of rodenticides on off-shore islands by inaccurately claiming that the rodenticides do not end up in the water, killing marine animals.  There is ample evidence that island eradications have killed many marine animals because rodenticide lands in the water when applied by helicopters. 
  • USFWS justified the killing of 500,000 barred owls in western forests by claiming they are an “invasive species.”  In fact, barred owls migrated from the East to the West Coasts via the boreal forests of Canada.  These forests were not planted by humans and have existed since the end of the last Ice Age, some 10,000 years ago.  The arrival of barred owls on the West Coast was a natural phenomenon.  Barred owls are therefore not “invasive species.” In a rapidly changing climate, many animals must move to survive.
  • Nativists claim that most insects are “specialists” that require native plants.  That claim is a gross exaggeration of the dependence of insects on native plants, which are sometimes confined to a family of plants containing thousands of both native and non-native species. 
  • Pesticide applicators also complain about “personal attacks.”  They are not alone.  I (and others) have been called “nature haters,” “chemophobes,” and “climate change deniers.”  Pesticide applicators feel abused.  So do I. 

I could go on.  The list of bogus claims of the superiority of native plants and animals is long and getting longer as more and more public money is available to conduct misnamed “restorations.”  Suffice to say, there is plenty of misinformation floating around invasion biology and most of it is used to defend destructive “restoration” projects.  The war on nature is also a war of words. 


(1) ­Justin Luong, et.al., “Lessons learned from an interdisciplinary evaluation of long-term restoration outcomes on 37 coastal grasslands in California.” Biological Conservation, February 2022.

The program for the Cal-IPC 2024 Symposium is available HERE.  Abstracts and presentation slides have not yet been posted to the website, but they will eventually be available to the general public. 

Dana Milbank: The evolution of a native plant advocate

Dana Milbank is a political columnist for the Washington Post.  Like many Americans, Milbank moved his family from urban Washington D.C. to a derelict farm in the foothills of the Blue Ridge Mountains in Virginia, seeking refuge in nature from urban confinement imposed by the Covid pandemic.  So began his war on nature, dictated by native plant ideology.

In a series of columns, WaPo readers observed how his battle against non-native plants developed:

  • The first installment of his “restoration” saga described the over-grown property that he believed he was obligated to tame:  “an entire civilization of invasive vines and weeds had cruelly exploited the inattention [of previous elderly owners].”  The vines were “murdering defenseless native trees.”   He hired a crew to clear brush, until the cost challenged his budget.  Then he bought equipment and tried to do it himself.  He concluded that he could not “restore order” to his land without using herbicides.  Even then, he was doubtful of ultimate success:  “Clearly, I won’t be defeating these invaders.  At best, I’ll battle them to a temporary truce, holding them at bay until I lose the will to fight them.”  Like many city-slickers, Milbank has an unrealistic vision of what nature looks like when allowed to take its course.
Kaweah Oaks Preserve, Visalia, CA.  November 2013.  California Wild Cucumber, also called manroot (Marah fabacea), climbing over a native valley oak.  Both native and non-native plants can be “invasive.” 
  • In the second episode of Milbank’s battle plan, deer were his target:  “I will be wielding my gun against a brutal foe—one that destroys our forests, kills our wildflowers, sickens humans and threatens the very survival of birds, mammals, insects and amphibians.  I am becoming a deer hunter.”   Where top predators, such as wolves and bears, have been eliminated by humans, there is an over-population of deer who browse vegetation, depriving other animals of the food and cover they need.  Again, Milbank has his doubts about the effectiveness of hunting deer on his property:  “I can’t pretend that my hunting will make a dent in the deer population.” 
  • After taking Virginia’s Master Naturalist Program, Milbank’s third episode expresses his regrets as a gardener:  “I’ve been filling my yard with a mix of ecological junk food and horticultural terrorists” and he warns urban and suburban gardeners that their gardens are “dooming the Earth.”  He takes aim at cultivars in general and many specific species of introduced plants.  Conservation Sense and Nonsense explains why most of these accusations are exaggerated, if not, patently false. 
  • In Milbank’s column, “How I learned to love toxic chemicals,” he expresses frustration about how hard it is to eradicate non-native plants:  “I was losing, badly, to the invasive vines and noxious weeds…I’d cut them back, but they would return in even greater numbers.”  He fully embraces the use of herbicides to escalate his war on nature:  “I have become a reluctant convert to chemicals.”  He acknowledges that glyphosate is toxic, but he claims that the cut-stump application method he uses is “surgical.” He wears protective clothing, including a respirator, which is not required by the product label or California law for glyphosate applications.  He is encouraged by Doug Tallamy, who calls herbicides “chemotherapy.”  Conservation Sense and Nonsense explains why herbicides are doing more harm than good to the environment and everything that lives in it.  

Throwing caution to the winds

In the latest installment of Milbank’s crusade against non-native plants, he tosses caution about herbicides aside. He hires a drone to spray a hayfield with glyphosate in preparation for creating a meadow of native grasses and forbs:

“To save the birds, I brought in this big bird: a 10-foot-square, Chinese-made drone with 8 propellers, capable of carrying 10 gallons of fluid, in this case glyphosate, to kill the grass in my hayfield. (It might seem counterintuitive to douse a field in herbicide to help nature, but conservationists broadly endorse the practice.)”

Herbicides are often sprayed from drones to eradicate non-native plants considered “invasive.” Source: https://www.researchgate.net/figure/Spray-drone-used-to-treat-a-patch-of-invasive-Lepidium-latifolium-on-Suisun-Marsh-The_fig3_372867398https://www.researchgate.net/figure/Spray-drone-used-to-treat-a-patch-of-invasive-Lepidium-latifolium-on-Suisun-Marsh-The_fig3_372867398

Milbank has abandoned his cautious use of herbicide and is now aerial spraying from a drone 30 feet over his head, while he watches, without wearing any protective gear:

“Shanley, in shorts, sneakers and fishing shirt, plopped in a lawn chair in the shade of my barn and, using a control pad with two joysticks, sent the drone into the sky… In a moment, the beast was airborne and, from a height of about 30 feet, spraying death on my hayfield. It sprayed the fescue. It sprayed the Johnson grass. It sprayed the foxtail. It returned, flew over the barn — and sprayed me with glyphosate. Programming error. “Sorry about that,” Shanley said. My eyes burned for two days.”

If he had been wearing safety goggles, as required for glyphosate applicators in California, he would have been spared. Milbank has the right to poison himself, his land, and the animals that live on his land.  Although the applicator may be breaking laws (he would be in California) by not wearing any protective equipment, Milbank isn’t doing anything illegal. 

If I weren’t reading his story in the mainstream media with a national following, I wouldn’t be writing about what he’s doing. I’m writing about Milbank’s dangerous use of herbicides because he has a big audience and his audience displays their ignorance of the dangers in over 1,400 comments.

The reader comments on Milbank’s latest article are uniformly positive, as were comments on his earlier installments about his war on nature.  Most comments are short expressions of unqualified praise, such as “You are doing holy work,” or “God bless you.”

A handful of comments (including mine) express concern about the indiscriminate use of glyphosate.  The few dissenting readers are blasted by Milbank’s supporters.  Some of their responses betray ignorance of herbicides: 

  • It’s not Round Up; it’s a safe herbicide.”  In fact, Milbank says he’s using glyphosate, which is the active ingredient in Round Up.
  • “He said nothing about dousing. It looks like a selective approach. In some cases, there is no practical alternative.”  In fact, Milbank says explicitly that he’s spraying 10 gallons of herbicide 30 feet over the ground from an aerial drone.  Does that sound selective?

The reader comments claiming that glyphosate is harmless brought to mind a recent article about the army of paid apologists for pesticides.  The pesticide industry, in collaboration with the US government, has “established a ‘private social network’ to counter resistance to pesticides and genetically modified (GM) crops in Africa, Europe and other parts of the world, while also denigrating organic and other alternative farming methods. More than 30 current government officials are on the membership list, most of whom are from the US Department of Agriculture (USDA).”

The most common defense of Milbank’s herbicide spraying was that it only needs to be done once, with an occasional follow up prescribed burn.  Milbank doesn’t actually claim that herbicide only needs to be sprayed once, but his supporters wish to believe that.  Here are a few actual attempts to convert non-native grass to native grass that illustrate that such a conversion is unlikely to be possible, even after a persistent, long-term attempt.

Dunnigan plot in August 2011, after 9 years of effort, described below. Source: https://www.ecoseeds.com/road.test.html
  • A team of academic scientists at UC Davis attempted to convert non-native grasses to native grasses on 2 acres of roadside.  At a cost of $450,000, they tried every available method (herbicides, plowing, plug planting, mowing, burning) for 9 years.  When they ran out of money, they declared success, which they defined as 35% native grasses that they expected to last for no more than 10 years. (See above)
  • The Invasive Spartina Project in the San Francisco Bay has been trying to eradicate non-native spartina marsh grass with herbicide for 20 years at a cost of $50 million.  The project was recently granted another $6.7 million to continue the project for another 10 years.  The project has killed over 600 endangered birds (Ridgway rails) in the San Francisco Bay because of the loss of habitat. 
  • One of the presentations at the 2022 conference of the California Native Plant Society was about a 20-year effort at the Santa Rosa Plateau Ecological Reserve to convert non-native annual grassland to native grassland, using 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.”  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.”
This map of the San Francisco Bay shows where herbicides have been sprayed on non-native marsh grass for 20 years. It is a BIG project!

Anyone with a little knowledge of how herbicides work, would know that glyphosate kills only the top-growth of an actively growing plant.  Glyphosate won’t kill the seed bank of Milbank’s hayfield, which he says has been growing there for decades, perhaps as long as 100 years.  That’s why glyphosate must be applied annually as the seed bank continues to produce new top-growth annually.  If Milbank plants native plants after the initial spraying, they will be killed by subsequent spraying because glyphosate is a non-selective herbicide, which kills whatever it touches, both native and non-native plants. Perhaps Milbank knows this, but his readers don’t.  It might explain why Milbank is not particularly optimistic about the prospects of achieving his goal of a native meadow:  “Will it work? I have no idea. It could become the field of my dreams…Or it could be a costly and time-consuming failure.”

Only two of Milbank’s readers mention the damage that herbicide does to the soil, making future plantings even less likely to survive.  One of those comments is from a farmer who has reason to know this important information: 

The number of things you screwed up, from possibly destroying that old man’s life, family, and farm, to messing up the winter food supply with a cascading effect for farms in your region, to obliterating a small farm, were appalling until you got to the part where you killed your soil microbes with poison. You actually killed topsoil with the idea you were going to grow healthy plants! If I were to write a caricature of a [sub]urbanite transplanted to a farming community and with the best intentions absolutely destroying everything, couldn’t have done any better than you have with your self-congratulatory actions. Farms are complex systems embedded in even more complex natural systems. Farms interact with and depend on each other. It’s where food comes from. When you kill one, you hurt all the others. You also hurt animals and plants that depend on the farm. Creating a farm, and a farming community, is hard. Destroying one is easy, and you just did it.”

This comment brought to mind a recent study about the damage that pesticides do to the soil.  A meta-analysis of 600 studies “…published in the journal iScience found that soil pollution was the leading cause of declines among organisms living underground. The finding has surprised scientists, who expected farming intensification and climate change to have much greater impacts.”  The co-author of the study said, “Above ground, land use, climate change and invasive species have the greatest impact on biodiversity, so we assumed that this would be similar below ground,” Victoria says. “Our results show, however, that this isn’t the case. Instead, we found that pesticide and heavy metal pollution caused the most damage to soil biodiversity. This is worrying, as there hasn’t been a lot of research into the impacts of soil pollution, so its effects might be more widespread than we know.”

A familiar story

Dana Milbank’s plans to transform a derelict farm into a native plant garden are the mirror image of the native plant movement in the San Francisco Bay, the region where I live and have observed failed native plant “restorations” for over 25 years:

  • Native plant “restoration” projects in the Bay Area began over 25 years ago based on the mistaken assumption that if non-native plants were destroyed, native plants would magically emerge without being planted.  In other words, nativists originally believed that the only obstacle to native plants was the mere existence of non-native plants.
  • After 25 years of applying herbicides repeatedly, there are no more native plants in the San Francisco Bay Area than there were 25 years ago.  The soil has been poisoned by herbicides and climate change and associated drought makes native plants progressively less well adapted to current environment conditions.
  • Despite the obvious failure of these “restoration” attempts, they continue unabated because vast sums of public money are available to keep them going.  Dana Milbank will run out of money eventually, but the public coffers are never empty.  Milbank is 56 years old.  When he gets too old to do the work or when he dies, whatever he has accomplished will quickly revert to its previous unmanaged state.  Nature will prevail and his brief conceit that humans can control nature will be history. 
  • The public is unaware of how much herbicide is used by public land managers because application notices are not required for most pesticides.  In California, for example, if the manufacturer of the pesticide claims that the pesticide will dry within 24 hours, application notices are not required by law.  Glyphosate is one of many herbicides for which application notices are not required.  Some land managers post application notices anyway, but many do not.  The public is also ignorant of the damage that pesticides do to the environment and everything that lives in it.