One of our first posts, nearly one year ago, was about attempts to eradicate broom (see “Broom: I’ll be back!”). It’s that time of year again, when the broom is blooming around the Bay Area, adding a dash of bright yellow color to our public lands.
Despite continuing efforts to eradicate broom, it makes this annual comeback, regardless of the method used to kill it. Mechanical destruction is one of the methods used. In the photograph taken in fall 2010 of a trail in Redwood Park we see the unsightly result of such an attempt to eradicate the broom shown in our first post about broom in spring 2010.
The UC Davis Statewide Integrated Pest Management Program predicts the results of this effort to eradicate broom: “Brush rakes and bulldozers often leave pieces of rootstalks that readily can resprout…using large equipment to clear land creates a perfect environment for new seedling establishment, making follow-up control essential.” So, we shouldn’t be surprised when we revisit this same site the next spring to find that although it is still unsightly, it is also covered with the resprouts of the broom.
Herbicides are also used to eradicate broom. The East Bay Regional Park District uses Garlon for foliar spraying of broom, despite the public’s concern about herbicide use in our parks. In contrast, Marin Municipal Water District (MMWD) has not used herbicides on its properties since 2005, in response to public protests. In December 2010, the Marin Independent Journal reported that MMWD is considering using Roundup (which is considered less toxic than Garlon) for broom control, but that a proposal will not be made until 2012 at the earliest, after an environmental impact study that will consider all alternatives for “pest management.”
Since the seeds of broom are known to live in the ground from 50 to 60 years, we should expect that it is very difficult to eradicate. Unless we make a commitment to kill the plant above the ground every year for as long as the seeds live in the ground, we cannot expect to be successful in that effort.
We were therefore amused by this exchange that Jake Sigg had with one of the readers of his “nature newsletter” (December 20, 2010):
Reader: “…We have been up there every year for about 3-1/2 years now…It has been quite instructive about how flat out difficult it is to reverse the process [of “displacement” of native plants]. Like most invaders, the non-native plants like it here and want to stay. The broom in particular are [sic] astoundingly persistent in holding whatever territory that they have gained. It sounds strange to say, that sometimes I think the project is an exercise in futility while at the same time is extremely satisfying work and will continue it into the indefinite future.”
Jake Sigg: “…It is such a lop-sided struggle…And yet, we all keep going. It is a paradox that I don’t understand. While working I’m fully aware of the seeming futility of what we’re doing, and yet keep going—and enjoying it!!”
Jake Sigg and his readers would benefit from the advice of Mark Davis in his book, Invasion Biology.* Professor Davis suggests that unless a non-native species causes great health or economic harm, we adopt the “LTL approach” i.e., “Learn to love ‘em” or at least “Learn to live with them.”
If it is futile to eradicate a plant we don’t like, if that plant isn’t doing us or any other plant any harm, and if we are damaging our environment in our futile attempt, let’s change our attitude toward that plant. If we can’t change the plant, it is still within our power to change ourselves. Surely we can find something more fruitful to do that is equally satisfying such as planting more native plants rather than destroying non-native plants.
Broom is an especially good candidate for LTL. It is green all year around. It requires no care whatsoever. And in the spring it treats us to a lovely carpet of bright yellow. What’s not to love?
* Mark Davis, Invasion Biology, Oxford University Press, 2009, page 150
Conservation Sense and Nonsense 
Broom thrives wherever trees are cut down. Broom grows in sunlight, so one way to keep broom from spreading is to maintain a shade canopy of tall trees. Another point: native coyote brush/bush is also considered broom; although it is a different species, it has many of the same characteristics as non-native brooms. Why work so hard to eradicate French broom while keeping coyote brush, which is equally, if not more, flammable and is not as attractive as French broom?
Webmaster: Good question, Madeline. Like much that native plant advocates do, it’s a mystery to me too.
I’m beginning to think there’s a certain comfort in futile tasks, whether performed as a volunteer or an employee. It provides a predictability that has gone missing from a lot of the world.
I wonder how Sisyphus *really* felt about rolling the rock up hill every day. Did he go Oh No! with a tired groan, or did he say with quiet satisfaction, “Rolling rocks uphill, it’s what I do; come on, rock, let’s go get our morning workout…” ?
At least he didn’t have to bathe it in Garlon or Roundup before he pushed it.
i have to say that it seems flat out crazy to kill or sicken the rest of us (people and pets, along with the flora and fauna/fish/bugs/etc.), when the only beneficiary of these eradication programs is the companies selling the chemicals.
I find this website very informative. Using pesticides and herbicides to eradicate non-natives that pose no immediate threat to health seems just stupid. Even for harmful species, like rodents, non-poisonous solutions are there. Not economically feasible you say–well how economically feasible are the illnesses caused by the chemical stew we now live in. It’s not so cheap to treat cancer and birth defects either.
Your slightly iconoclastic approach to non-natives and to “pests” reminds me of the wonderful work of the Martinez beaver group, called “Worth a Dam.” Their website, Martinezbeavers.org has a wealth of information about the underrated and often persecuted beaver, those wonderful ecological engineers, whose benefits to habitat are now beginning to be appreciated.
You people need to read “Bringing Nature Home….” by Douglas Tallamy. It turns out that native plants support the reproduction of native songbirds and other wildlife, while introduced plants are much less effective. It’s about more than us.
Bill Stringer
Webmaster: This is one of many assumptions made by native plant advocates that are not supported by scientific evidence. Many studies indicate that non-native plants support as many insects as native plants. This is the post that reports these studies: https://milliontrees.wordpress.com/2011/05/25/a-dialogue-about-insects-and-non-native-plants/
We agree that the debate about native plants is “about more than us.” One of the reasons why we object to the needless destruction of non-native plants is that many animals are using those plants for food and cover.
So you’re going to love it when all of our open spaces are completely covered with mono-cultures of only a few vigorous species of plants like the exotic brooms, star thistles, other thistles, rye grass, pampas grass, goat grass, veldt grass, pretty periwinkle and forget- me-nots – with none of those ugly, diverse Ca. natives left ? Wait a minute, it’s like that already in many places, enjoy!
Webmaster: Ah yes, the familiar dark and gloomy predictions of native plant advocates. We know them well. In fact, few of the non-native plants and trees being eradicated by native plant “restorations” are invasive. We have scientific studies as well as historical photographic evidence that non-native trees have not spread beyond where they were planted over one hundred years ago.
The few truly invasive species, such as broom and oxalis are most likely to spread where the land has been disturbed by development because they are better adapted to current climate, air quality, and soil conditions. Trying to remove them is usually futile even if we are willing to tolerate the prescribed burns and herbicides used in the effort to eradicate them.
And yes, many of these introduced species are at least as attractive as California natives, most of which are brown and dormant half of the year. We are reminded of the recent removal of a lovely patch of forget-me-nots that was replaced by a thick mulch of chipped eucalyptus wood. Not an aesthetic improvement and we doubt that the native bees that are prevented by the mulch from nesting in the ground consider it an improvement either.
If you were referred to the Million Trees blog by comments on today’s article in the NY Times, you don’t seem to have read that article. We recommend it to you. It cites a study which reports that 97% of the native plants that existed in San Francisco when the city was founded in 1850 still exist in San Francisco. So your doom and gloom prediction does not correspond with reality.