July 12, 2001
Pesticide-free parks teach new lessons
By TRACY DIECKHONER
City of Seattle
The city manages over 110,000 acres of public land, of which 12,000 are highly developed and managed grounds. It’s a complex task encompassing far more than the obvious picnic grounds and ballfields. City-owned landscapes include miles of electrical transmission right-of-way, greenhouses, golf courses, a conservatory with rare plants, specialty gardens like the Japanese Garden at the Arboretum, roadsides and medians, and electrical facilities where a weed can actually result in electrocution.
With such diverse lands to manage, maintenance issues such as invasive weeds, destructive insects and diseases become magnified. Despite these challenges, the city applies a minimal amount of pesticides in caring for our public lands. When necessary, pesticides are applied in a targeted manner by trained crews as part of an Integrated Pest Management or IPM program.
IPM includes monitoring, improving plant health, establishing pest tolerance thresholds and considering non-chemical controls such as physical, mechanical and biological. By using these methods, city crews have steadily reduced the amount and toxicity of the pesticides used over the last 20 years.
The evidence linking pesticides with adverse health and environmental impacts, including effects on salmon, is growing. So while our use of pesticides is minimal, the city is going well beyond legal requirements, instead taking a precautionary approach to use of pesticides. For example, we don’t want to use products known to persist in the environment or move readily through soil or those that have been linked to endocrine disruption or cancer.
To help us define these characteristics and determine which pesticide products were the most potentially hazardous, the city contracted with the Washington Toxics Coalition, a local non-profit organization dedicated to promoting alternatives to toxic chemicals. Working with the coalition, we translated the general chemical use criteria contained in Seattle’s Environmental Management Program (our system for identifying and reducing environmental impacts) into pesticide-specific criteria.
In 1999, the city adopted a pesticide reduction strategy with two targets: 1) phase out the use of the most potentially hazardous products by June 2000 and 2) reduce overall use by 30 percent by end of 2002. We are proud of the fact that the first target was met on schedule and we have already surpassed the second target by achieving a 46 percent reduction in overall use.
Building on these successes and the lessons learned, Seattle just launched a Pesticide-Free Parks program. Six parks, each in a different neighborhood, have been designated pesticide-free: T.T. Minor Playground (Central District), Webster Playground (Ballard), Meridian Playground (Wallingford), Fairmont Playfield (West Seattle), Bradner Gardens Park (Mount Baker Ridge), and Beer Sheva Park (Rainier Valley). These parks will serve as laboratories for demonstrating environmentally friendly practices and for testing new technologies. An additional eight parks (not considered “feature parks”) have also been designated pesticide free.
Parks chosen for the program represent a range of maintenance challenges and provide convenient access to a variety of neighborhoods. The program will help the city better understand how to sustain public land over the long term without using pesticides.
In order to maintain these parks without creating a disproportionate labor demand, the city is making some improvements to them. Installing hard borders around plant beds and tree rings and concrete pads under picnic tables will reduce trimming needs. Sealing cracks in concrete and maintaining a good mulch layer in beds will also help prevent weeds. Plant density and low maintenance landscape designs will be increased. The city’s landscape maintenance guidelines stress the value of native or naturalized plants, which attract wildlife and may require less maintenance naturally.
Other techniques for controlling pests are also used. You may see crews using radiant heat weeders, essentially propane-powered heat wands, which “cook” weeds. We are also using biological controls to manage insect pests. If you see a white cardboard box without ends hanging from a tree, know that we are monitoring pest populations so we will be able to target the release of beneficial insects.
Interpretive signs will be installed in the feature parks describing the practices we are demonstrating and the innovative approaches being tested. Many of these techniques also work when managing residential yards. Give the folks at Seattle Public Utilities Natural Lawn & Garden Hotline a call at (206) 633-0224 for ideas. The Washington Toxics Coalition (632-1545) is also a good resource for information about least-toxic pest management.
You may wonder why all city property isn’t pesticide-free. Weed and pest management is a huge challenge with such a large amount of land to manage, as well as safety and legal considerations including roadway lines- of-sight and noxious weed control, Nonetheless, the city’s pesticide-free successes are not limited to parks. Pesticides have not been used in library landscapes for over two years and some City Light landscapes are being maintained pesticide-free as well.
The parks will teach us more about sustaining and enhancing public lands in the most environmentally friendly way possible. Lessons learned will be taken to other city property. You may see some changes, including a more natural look, as the city and its grounds crew continue working environmentally sound landscapes. So look for the Pesticide-Free Park dragonfly logo and let us know what you think.
Tracy Dieckhoner is a policy analyst and program manager with the city of Seattle’s Office of Sustainability and Environment. She can be reached at (206) 386-4595.
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