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