Wildflower is published quarterly by the Wildflower Center. Its content is national in scope with articles about the conservation and use of native plants as well as news from the Wildflower Center. A subscription is provided to Wildflower Center members as a benefit of membership.
Chemical Reaction - Summer 2007
For Nancy-Clair Laird it was an issue of awareness. In June 2005 Laird and a neighbor took their young children to play together in Beall Park in downtown Bozeman, Montana. "On the opposite side of the park, we saw a truck with about a 10- gallon drum and several nozzles spray chemicals on the grass," Laird says.
Enamored by the large truck, her son Will, then 2 years old, began chasing after it. The chemical in the metal drum was 2,4-Dichlorophenoxyacetic Acid (2,4-D). This common herbicide is widely used to combat dandelions, thistles and other broadleaf weeds.
Part of Laird’s surprise came after learning that the park was routinely sprayed during early-morning hours, before patrons arrived. "It was their practice to spray early and then drive off without telling anybody," Laird explains. At the time, she was pregnant with her second child. She immediately asked the driver to stop spraying and then embarked on a campaign to increase awareness and garner community support to eliminate pesticide use in the park.
Across the country, citizens like Laird and her neighbors are advocating alternatives to chemical methods of pest- and weed-control in private yards and gardens as well as community green spaces. Some choose organic pesticides, while others trade chemicals for pulling weeds by hand. Others view chemical methods only as a necessary and last resort to costly or impractical means of controlling troublesome invasive plants. Still others favor innovative landscaping techniques for pest control over the use of chemicals. Although their motives differ, all share a common quest for healthy green spaces in which people can play, explore and rejuvenate.
Green spaces offer opportunities for exercise, which has been proved to help reduce the risk of certain diseases that are linked to obesity and a sedentary lifestyle. They also provide psychological benefits. For example, one 2001 study by researchers at the Landscape and Human Health Laboratory of the University of Illinois at Urbana-Champaign reported improved symptoms following activity in green settings compared to those following activity in non-green settings. The chemical pesticides often used to keep these green spaces usable and attractive, however, can produce harmful effects.The U.S. Environmental Protection Agency (EPA) defines pesticides "as any substance or mixture of substances intended for preventing, destroying, repelling or mitigating any pest."
The agency says that although it is often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides and various other substances used to control pests.
The pesticide 2,4-D that was sprayed to control dandelions in Beall Park is used worldwide for landscape and agricultural use. The EPA includes it among a list of commonly found pesticides in U.S. public drinking water systems. According to the agency, 46 million pounds of 2,4-D finds its way into green spaces in the United States each year. Sixteen million pounds, or 34 percent of this amount, are used for turf, lawns, forestry and residential applications.
The herbicide is popular around the world because of its ability to kill broadleaf plants like dandelions while sparing grass. Concerns over the potentially harmful effects of its use, however, are prevalent in the United States and abroad.
The EPA links chronic exposure to high levels of 2,4-D to damage to the nervous system, liver and kidneys. Despite the many allegations that 2,4-D causes cancer, the EPA asserts that it is unlikely that exposure to 2,4-D resulting from its limited use would pose a carcinogenic risk to humans.
Although the pesticides of today persist for far less time in the environment (compared to older pesticides like DDT), traces of some still can be found in water, air and food weeks and months after application. Additionally, the cumulative effects of repeated low-dose exposures in our bodies have not yet been fully explained and are difficult to gauge, according to Daniel Sudakin, M.D., an associate professor for the Department of Environmental and Molecular Toxicity at Oregon State University.
Despite the attention paid to the harm these chemicals can do, some activists believe that public awareness of pesticide and fertilizer use still seems to lag. "No one knew that they sprayed the parks in Bozeman, even long-term residents," Nancy-Clair Laird says. Activists in this city of 32,500 residents are working hard to increase awareness and bolster the health of community green spaces — to ensure that they do more good than harm. Laird posted her own signs to alert patrons after Beall Park was sprayed and conducted research about the effects of the chemicals being used. Ultimately, the efforts of Laird and other neighbors paid off.
In November 2005, Bozeman began a pilot project in Beall Park, making it the city’s first pesticide-free park. This means that pest and weed problems in the park are now addressed entirely without the use of chemicals. The city also stepped up efforts to increase public awareness of local pesticide use. The city’s parks department now posts signs when spraying in other parks and provides information on their website and in the city’s newspaper.
Later that year, Helena, Montana, followed suit and made Pioneer Park, the city’s most visible park, pesticide-free. Rather than using synthetic, petroleumbased fertilizer, the city now uses a biologically based organic fertilizer.
Parallel efforts are underway across the country as other local parks departments scale back the use of chemicals in public spaces and seek healthier alternatives.
In 2005, Lawrence, Kansas, initiated a pilot program in Buford Watson Park in response to interest by local citizens and a city commissioner. Now, 34 of the city’s 52 parks are pesticide-free.
This city’s program relies heavily on volunteer support and utilizes landscaping techniques such as mechanical tilling, flame weeders, vinegar and mulching to keep weeds at bay, explains Crystal Miles, horticulture manager for the Lawrence Parks and Recreation Department. "I believe the project has been successful in better informing the public and reducing the use of pesticides in the park system," Miles says.
Organizations like the Northwest Coalition for Alternatives to Pesticides are also working hard to promote additional pesticide-free parks. In partnership with the coalition, Portland, Oregon, began a three-year pilot program in 2004 in three neighborhood parks using volunteer help during monthly work parties to weed and mulch. For two years starting in 2002, Seattle’s city government initiated a series of design changes and landscaping improvements in 14 pesticide-free pilot sites throughout the city. As part of the project, they tested how these improvements would reduce staff time necessary to remove weeds in shrub beds by hand instead of routinely applying an herbicide. Twenty-two of Seattle’s city parks are now pesticide-free.
The organization’s pesticide-free parks program coordinator, Megan Kemple, explains that initial high costs typically represent the greatest barrier to making community green spaces pesticide-free. "Manpower is expensive, and pesticides are cheap," she says. "However, the long-term costs to the environment and human health are not incorporated."
Some cities have resolved this issue by enlisting the help of volunteers. "The programs have worked best in smaller cities like Helena and Bozeman where volunteers do most of the work," Kemple says. "The program has also worked well in Seattle because the city really embraced the idea."
The existence of pesticide-free parks also helps educate residents in these cities about the harmful effects of some chemical pesticides and alternatives to using them in their backyards. "Our long-term goal is to educate people about alternative methods," Laird says. "Most people are in the mindset that you have to spray."
The publication of Rachel Carson’s Silent Spring in 1962 increased public concern about the health hazards of chemicals in our environment, but the use of pesticides and fertilizers remains prevalent. In 1998 and 1999, 74 percent of households used at least one form of pesticide, according to the Environmental Education and Training Foundation.
Many chemical-free pest-control advocates say that better education of alternative methods and realistic outcomes to different methods is needed. "People who use less-toxic or non-toxic management need more information," says Norma Grier, executive director of the Northwest Coalition for Alternatives to Pesticides. "We would like to see all public spaces pesticide-free. We are pleased when cities establish programs that move in this direction, and we are happy to work with them as they increase their adoption of alternatives to pesticides."
Many garden experts advocate integrated pest management, an ecosystem-based strategy that seeks to minimize the presence of pests by using prevention first and relying on chemicals as a last resort.
Sustainable management strategies also hinge on increased manual labor and preventive measures. For example, the use of hand- and electric-powered tools instead of gas-powered mowers and trimmers reduces air pollution associated with yard care. Mulching around plants not only prevents weeds but also adds nutrients, retains moisture and decreases soil erosion, according to Kemple.
Changes in landscape design and simply allowing a more natural appearance also can significantly decrease the use of chemicals and resources and create less waste. "Some parks opt for a more natural appearance by allowing dandelion and clover to grow," Kemple explains.
Among visitors to Beall Park, the attitude toward dandelions has changed. The community now gathers for the Dandelion Celebration in May to pull weeds, learn about different culinary and medicinal uses for dandelions and celebrate the "weed" that for many has become a symbol of the improved health of their local park.