San Francisco Herbicides 2015: Why Better Isn’t Good Enough

SF Natural Areas Pesticide by Active Ingredient 2008-2015 sm

NAP’s pesticide usage is down again in 2015

We have some nearly good news. After years of increasing pesticide until 2014, the 2015 data shows Natural Areas Program (NAP) again used less herbicides than in the year before – though they applied it more often. The volume of herbicide used was the smallest amount since 2010, but the number of applications the highest since 2008 (the earliest data we have).

So why isn’t this good enough?

  • The main reason is the growing consensus that herbicides are more toxic than the manufacturers claim. Roundup (glyphosate), long regarded as a “safe” pesticide (though not by us – we wrote about the worrisome scientific data HERE and HERE) has been declared a probable carcinogen. Herbicides don’t have a place in our parks where they could impact people – especially those who have reasons to worry about their toxic load – children, who are more sensitive because of their size and fast growth, and pets. People just don’t want any herbicides in our parks, especially in “Natural Areas.”
  • SF Natural Areas Program Number of pesticide applicns 2008-2015 sm

    But the number of applications is up.

    The second is that though NAP has reduced the amount of herbicides they use, they have considerably increased the number of applications. This means that park-goers have a higher probability of encountering pesticide use.

  • Some of these pesticides remain in the soil and environment for months, even years, after application. Imazapyr’s breakdown product is a neurotoxin. Many of the Natural Areas are on high ground, or in watersheds, and poisons applied there can spread unpredictably.
  • NAP used a dispropotionately large amount of the most toxic herbicides compared with all of SF Recreation and Parks Department (SFRPD):
    • 35% of the Roundup (glyphosate);
    • 80% of the Garlon (triclopyr) and
    • nearly 100% of the Stalker (imazapyr) and Milestone (aminopyralid).


A case in point is Garlon (triclopyr). This is one of the most toxic herbicides permitted on city-owned properties, with a Tier I (Most Hazardous) rating.

Photo credit: Badjonni (Creative Commons - Flickr)

Photo credit: Badjonni (Creative Commons – Flickr)

NAP is the most regular user of Garlon, mainly to poison yellow oxalis.  In 2015, it accounted for 80% of the Garlon used by SFRPD.They are trying to reduce usage with a new surfactant (the stuff used to dilute the herbicide and let it spread better), CMR Silicone Surfactant. We are unsure whether this is an improvement but will research it further. The Label is here: Cmr_Silicone_Surfactant_(0198050402)_Label

If NAP stopped trying to poison oxalis each spring, Garlon could be removed from the approved list of pesticides. Instead, they used Garlon five times in December, on Twin Peaks, Glen Canyon, Mount Davidson, and McLaren Park. These are places where children and pets could easily encounter the herbicide.

coyote pouncing in oxalis field - copyright Janet Kessler

There’s no need to battle oxalis. It’s beloved by children, attractive to bees and butterflies, useful to other wildlife in the food chain, and a valuable plant that improves the soil for grasses. Moreover, it disappears after its flowering period is over. There is no evidence that it adversely affects other plants in what is essentially a non-native grassland.


Roundup is the most commonly used pesticide in our parks, and NAP uses a disproportionate amount. It applied Roundup over 70 times in 2015, and the volume used was more than in 2014. We would have expected that after the World Health Organization finding, NAP would stop using this herbicide. It appears not.

The problem is that NAP targets a lot of plant species it considers invasive – at the last count, around three dozen different species. Unless it changes its objectives, it will always need herbicides – Roundup, Stalker/ Polaris, Milestone VM, Garlon 4 Ultra. If it reduces one, there’s a temptation to increase another.


San Francisco can get rid of herbicides in natural areas. It will mean a change in the mindset of land managers. Non-native plants are valuable in wild places for their ecological benefits – carbon capture, wildlife habitat and food, soil enrichment and erosion prevention among others. If we must create native plant gardens, they should be small enough that they can be managed by manual gardening. Though we have issues with what UCSF is doing in Sutro Forest, in one matter they have a clear win: No pesticides have been used there since 2008, and UCSF have committed not to use any herbicides in Sutro Forest. That includes the native plant garden on the summit.


SFRPD Pesticides (ex Harding and NAP) 2013-15SFRPD reduced its herbicide usage in 2015 as well. The numbers for 2014 were exceptionally high because of large amounts of Tier I pesticides used in the Kezar Stadium renovation, and mistakenly in Gleneagles Golf Course. Without those two factors, usage would have declined in 2014 and been nearly flat in 2015.

A word about Greenmatch and Avenger. These are based on lemongrass oil, or what is called a “botanical.” It’s actually considered acceptable for organic gardening. However, it’s classified as Tier II because it can cause allergic reactions in its undiluted form.


The renovation of Kezar Stadium has used a lot of Tier I herbicide.

  • In November and December 2014, they used 208 fluid ounces of Drive XLR8 for turf renovation. This was a one-off Tier I pesticide use, and may have been associated with bird deaths in the area.
  • In February 2015, they used 320 fluid ounces of Fiesta, also classified as Tier I, followed by 24 ounces of Aquamaster (which was subsequently classified as Tier I).
  • In June 2015, they used 16 ounces of Turflon (triclopyr), also Tier I and one of the few times any SFRPD department but NAP used triclopyr.

They have also used some Tier III herbicides – actinovate and fosphite – which we presume are a lot less toxic. (Edited to Add: They are not included in the graph above for that reason.)

Truck-size Loopholes in San Francisco’s Pesticide Plan

If you oppose the use of toxic herbicides in our parks, you may wish to attend a San Francisco Department of the Environment (SFDoE) hearing on  Wednesday, December 16, 2015, 4:30-7:00 pm in the Downstairs Conference Room, 1455 Market St. (near 11th St.; Van Ness MUNI stop)

glen canyon glyphosate imazapyr 2012 barack doggie

Did Roundup Kill this Dog?

SFDoE manages the Integrated Pest Management program, which decides which pesticides may be used on city property.  It classifies the permitted pesticides into three tiers: Tier III is the Least Hazardous; Tier II is More Hazardous; and Tier I, Most Hazardous. It recently reclassified Roundup /Aquamaster (active ingredient glyphosate) as Tier I after the World Health Organization declared glyphosate a probable carcinogen.

SFDoE is going to discuss some new rules restricting Tier I pesticides. We were hopeful, because we believe SFDoE does try to reduce pesticide use, and we thought the recent public outcry  would strengthen their resolve to prohibit pesticides unless public health and safety were affected.

(There’s a good article on the public opposition here: Public Opposition to Pesticide Use in Our Public Parks.)

For the record, and as our supporters already know: San Francisco Forest Alliance stands for No Pesticides in our Parks.

So we were hopeful, in fact, until we read the draft rules. They contain truck-sized loopholes, and will not substantially reduce pesticide exposure for San Francisco’s park-using families, including small children and pets.

SF Draft Restrictions on Tier I Herbicides Nov 2015

(You can download the PDF here: San Francisco Draft Restrictions on Tier I herbicides )


Exception number 11 says that these herbicides may be used on “Invasive species posing a threat to species or ecosystems of value to the community.” Since that’s the entire justification that the SFRPD’s Natural Areas Program (NAP) gives is that it’s using these toxic herbicides on invasive species, they won’t need to change anything they do.

toddler holding oxalisWhat this means: NAP claims large areas of our parks as so-called “natural areas”  – over 1000 acres in 32 parks. It includes most places people like to hike with kids and dogs like Mt Davidson, McLaren Park, Glen Canyon, Bernal Hill, and Pine Lake. They spray Tier I and Tier II herbicides on over 30 different species of plant. Some are close to the ground, like oxalis. Others are bushes, like blackberry, where they don’t stop spraying even in the fruiting season when everyone including kids are eating berries off the bushes.

This video showing glyphosate and imazapyr being sprayed on blackberry was taken on Mt Davidson only a few weeks ago.


parent and child with oxalisProposed rule number 4 prohibits use of Tier I pesticides on “the grounds of schools, preschools, or children’s playgrounds.” This is certainly an improvement, but it’s hardly enough. Playgrounds and preschools in particular are often inside parks, and if the parks can use these pesticides, then the children may well be exposed on their way into or out of the area, especially if they stop to hike or play in natural areas. Glen Canyon is an example – a preschool abuts the natural areas, which, as we noted above, gets a free pass. In McLaren Park, much of the park is a natural area, including areas close to playgrounds. (All the colored areas on the map below are claimed by NAP.

mclaren NAP Map 1


Another permitted use is in landscape renovations (Exception 10). We presume this applies to such projects as Kezar Stadium and Marina Green, both of which used substantial quantities of Tier I herbicides. It requires the public to be excluded for 4 days after the spraying. However, there’s growing evidence that some of these pesticides are persistent for a lot longer than 4 days.  Again, these are landscapes where our kids and pets play, often for hours at a time.

Two other exceptions also increase risk of exposure: Tier I herbicides may be used on poison oak near paths, and on trees or weeds posing a public safety, public health or fire hazard. Since pretty much any shrubs or trees can be deemed a hazard, this again means that herbicides can be freely used. And as more trees are removed near paths and trails, poison oak thrives in the sunnier areas – and justifies more Tier I herbicides.

In fact, another document for the meeting suggests a more aggressive attitude to trees. If any department wants to use pesticides not on the approved list, it can ask for an exception. The SFPUC wanted an exception for “Bonide Sucker Punch.” The problem, as they set it out was as follows:

When only some of the stems of eucalyptus and acacia of a multi-trunk tree are cut, the response of
the tree is to produce a vigorous re-growth of stump sprouts and suckers. The usual treatment of stumps is to paint the cut surface with a translocating herbicide, such as glyphosate or triclopyr. However this treatment kills the root system of the tree, killing the standing live stems of the tree. These present a hazard if they subsequently fall over. NAA is a synthetic plant hormone that suppresses re-growth  of suckers without killing the roots.

The exception was rejected, with this solution proposed instead – cut down the entire tree, not just the bits that are intruding into the right-of-way! And then paint the stumps with a Tier I herbicide (Roundup or Garlon), which will destroy the entire tree and, if other trees are nearby, potentially damage their roots as well. So instead of a solution that preserved the tree while limiting the damage, SFDoE approved a method that would be much worse.

We also note that in recent months, SFRPD NAP staff have apparently been deployed to apply herbicide on SF PUC property. This suggests that SFPUC is also buying into the destructive NAP approach.


Each year, SFDoE holds a hearing where they review changes to the list of approved pesticides, listen to the justifications for exceptions during the year, and take comments from the public. It’s usually held in a round table format in City Hall, with free discussion. This year, they will also discuss the new rules. With the recent outcry against pesticide use, they expect a much larger turnout and have changed the venue. Please be prepared with a comment of no more than 2-3 minutes long.

Annual Public Hearing on Pest Management Activities on City Properties  and San Francisco’s Draft 2016 Reduced-Risk Pesticide List

4:30-7:00 pm Wednesday, December 16, 2015
Downstairs Conference Room, 1455 Market St. (near 11th St.; Van Ness MUNI stop)

kid and pesticides2

The Natural Areas Program and Pesticide Use

Pesticide Application Notice - Mt Davidson (Nov 14 and 15th, 2013)

Pesticide Application Notice – Mt Davidson (Nov 14 and 15th, 2013)

We recently received a response from Phil Ginsburg, General Manager of the San Francisco Recreation and Parks Department (SFRPD) , to our concerns regarding the “Natural Areas Program”  (NAP). We thank him for the detailed response, but we still have a number of points of disagreement.

One of them is herbicide use. His letter states, “As a percentage of our overall total, herbicide usage in the Natural Areas comprises only 4%.”

As readers of this website know, that’s very different from our own analysis. We find that NAP uses nearly as much of the ‘Most Hazardous’ and ‘More Hazardous’ herbicide as the rest of SFRPD (ex Harding Golf Course).

And the discrepancy is the more surprising since the source documents are the same – the Monthly Pesticide Use Reports each section submits.

The graph below compares NAP and other SFRPD (ex Harding Golf Course). Not only is NAP clearly using much more than 4%, it also is the largest user of the Most Hazardous (Tier I) chemicals. (The San Francisco Department of the Environment – SFDoE – produces a  “Reduced Risk Pesticide” list each year. This lists pesticides that may be used on city-owned lands, and gives them Tier ratings.)

NAP vs SFRPD Other 2013 by Active Ingredient


Since we don’t know how Mr Ginsburg’s percentage is derived, we can only speculate. Some possible reasons:

1)  Our numbers leave out Harding Golf Course, but they include it.

Here’s why we exclude it: Harding Park Golf Course is under contract to be maintained to tournament-ready standards. This means it uses a lot of pesticides; but it really is outside SFRPD control if San Francisco is to have a PGA-standard golf course. (The city’s other golf courses, where SFRPD actually can determine pesticide use, actually use very little.  Sharp Park, for instance, has used none since August 2010.)

2)  Our numbers are for the most recent year, 2013.

Though the phrasing of the sentence suggests that are considering current usage, they may actually have used historic numbers.  It’s possible that other sections of SFRPD reduced their herbicide usage, even while NAP’s herbicide usage went up. NAP herbicide use rose annually from 2009 through 2013.

B&W Herbicide Use - Natural Areas Program

3) We have only considered the chemicals that are most concerning – the “more hazardous” and “most hazardous” herbicides (those the San Francisco Department of the Environment classifies as Tier II and Tier I) and omitted the “least hazardous” ones (Tier III).   Possibly SFRPD has included Tier III herbicides. We think this would distort the comparison; it would be like comparing pineapples and hand-grenades.

4)  If it’s based on the SF DoE’s new database, it may have data-entry errors, especially for data since 2010 when the new database was instituted. We compiled the Monthly Pesticide Usage reports ourselves, and re-checked them.


For anyone who wants to replicate our calculations, here’s how we made them:

  • We obtained Monthly Pesticide Usage reports from SFRPD under the Sunshine Act. If any of them were unclear, we got clarifications.
  • We compiled this data into a spreadsheet. Then we calculated Tier I and Tier II herbicide usage separately for NAP and for all other SFRPD (excluding Harding Golf Course), using SF DoE’s ratings.
  • We show “Greenmatch” separately – it’s rated Tier II, but it’s an organic herbicide that is less harmful than most Tier II products. Until 2013, it was rated Tier III, least hazardous.
  • [ETA:  We calculated the “Active Ingredient” quantity by using conversion factors provided by the manufacturer of each chemical. (These are available online.)]

In the first two months of 2014, NAP was still the major user of Tier I herbicides, using 8 times as much as all the rest of SFRPD ex Harding.




Comments from our Petition to the Mayor

mt davidson forest - hiker on trailBack in October 2013, we saw a report on SFGate (the online presence of the SF Chronicle) saying that Mayor Ed Lee would be responding to petitions addressed to him on if they crossed a certain (unspecified) number of signatures. The interview wasn’t with Mayor Lee, but with Jake Brewer, his Director of External Affairs. (The link to the relevant page was included in the article. It’s HERE.)

We’ve had a petition up for a while now, asking Mayor Lee to rein in the Natural Areas Program (NAP) that is destroying trees, restricting access, and using toxic herbicides in Natural Areas. (That petition is HERE.)  It has over 1500 signatures on it. But though that’s still live, it’s at, a different (though similar) organization to

Mayor Lee Stop NAPSo we started another one on the proper page at that gained superb momentum, exceeding 1,000 signatures in the first month. (Please sign if you haven’t already done so – click on the yellow button to go to the petition.)

this scene will be gonePeople are passionate about these natural areas, and they don’t want San Francisco Recreation & Parks Department to fell trees, use toxic herbicides, or restrict access.

A  tiny selection from the hundreds of comments on the petition (with added emphasis):

  • “Our parks, like Glen Park and Sutro Forest, are beautiful. Please don’t let them become barren wastelands.”
  • “Our city parks are looking like war zones with so much destruction. Just look at Glen Park.”
  • “Mt. Davidson is beautiful and healthy the way it is. It has its own wildlife and ecosystem. It was nothing before Mayor Sutro had those tree planted. Pls don’t disrupt it. Also, it is definitely NOT a fire hazard.”
  • “We need more trees in our urban environment, not less. Herbicides are dangerous for the overall environment and often the consequences of use do not show for years to come. Greenery in urban areas is beneficial to our health and well-being.”
  • “Herbicides are dangerous to children, adults and animals. This space is enjoyed by all–keep it safe, keep it open, keep the trees and healthy undergrowth.”
  • “Stop messing with NATURE!!!”
  • “Trees are the lungs of the planet. We need them to help to slow down impending climate catastrophe. Don’t poison the earth with herbicides — they are toxic to all living things, especially young children and pregnant mothers.”
  • “There are 100s of people who have given scientific and emotional reasons to prevent the deforestation of the Sutro / Mt. Davidson Area. It is easy to destroy an area that took a hundred years to create. I can only wonder about the ulterior motive for this mindless plan. Obviously it is the desire to develop this land. So once again commerce and immediate financial gain is at the root of this mindless proposal. Please think again! Next you will want to uproot the inhabitants of SF that are not “native”. They have adapted and now fit in with our plan. Because these trees have been here longer than you or I, they no longer need a great deal of care to grow and thrive. ANYTHING new that is planted will require at least 10 to 15 years of very careful nurturing. I live on Warren Dr. where a neighbor cut down all the trees and shrubs, on his property and on the easement, in order to plant native plants. The result was that about 4 years later, after a heavy winter rain storm, one side of his car was buried in mud. Terrific!… that is native to California!”

glen-canyon-glyphosate aminopyralid june 2012