Pesticide Reduction

The Horticulture Program has a long history at Seattle Parks and Recreation. It began at the beginning of the 20th century when the Park Commission invited the Olmsted Brothers to plan and design the framework for the park and boulevard system for the City of Seattle. Our Best Management Practices guide our work in the management and maintenance of landscaped and natural park land.

The City of Seattle has committed to reducing the use of herbicides, insecticides, and fungicides in all City landscapes. Together, 6 City departments manage over 110,000 acres of public land, of which 12,000 acres are highly developed and managed grounds including greenhouses, specialty gardens, roadsides and medians, golf courses, and hundreds of miles of electrical transmission right-of-way, plus over 1700 acres of greenbelts, open spaces and urban forest lands. The goals of the pesticide reduction program are to eliminate the use of the most potentially hazardous herbicides and insecticides and to continuously seek strategies to reduce overall pesticide use.

Bee City
Seattle Parks and Recreation's Horticulture division leads the City's Interdepartmental Team on Integrated Pest Management (IPM), with representatives from Seattle Department of Transportation, Seattle City Light, Seattle Public Utilities, Seattle Center, and Finance and Administrative Services. In response to national concerns about pollinators, on September, 2014, The City passed Resolution 31548, Banning the Use of neonicotinoid insecticides on City properties and on May 18, 2015, the city became a Bee City, U.S.A., institutionalizing the commitment to collaborate with the community on establishing and maintaining healthy pollinator habitats within Seattle.  For more information see the Bee City Seattle pages of our Bee City partner, The Common Acre: Bee City Seattle.

For more information about Citywide Pesticide Use Reduction Strategy and Pilot Project Information contact the Office of Sustainability and Environment at 206-615-0817 and visit the Pesticide Reduction Website.

The Pesticide-free Parks Program is one way we can help reduce pesticide use. Seattle Parks and Recreation has been maintaining 14 parks without the use of any pesticides since 2001. The program is expanded to include eight more parks and about 25 more acres, for a total of 22 parks and about 50 acres.

Pesticide-free Parks are distributed geographically throughout the city and provide citizens an opportunity to use these facilities with the knowledge that no pesticides are used. Parks and Recreation staff are using this program to adapt sustainable maintenance practices and design guidelines that can be widely used in park landscapes.

Integrated Pest Management

Pesticide Free ParksSeattle Parks manages over 6200 acres of natural area and park landscapes within our urban area; 2,300 acres of this is developed parkland. These landscapes provide a recreation experience for visitors and habitat for a variety of urban wildlife, insects and plants. While most of these plants and wildlife co-exist peacefully within our landscapes, these habitats also include pest species that may have no impacts in a given environment or spread out and take over the ornamental landscapes or native woodlands. Pests can be insects, plant diseases, invasive weeds, animals and birds. Pests disrupt the natural ecology of a habitat and landscape, creating an unhealthy environment for plants and sometimes humans and pets, and can also cause structural damages to buildings.

Seattle Parks practices Integrated Pest Management, or IPM. By using IPM, our staff first identifies the pest and then determines whether a given pest is actually impacting the park. The actual level of impact or damage in a given site determines whether staff might leave the pest alone, or manage the situation. If the pest impact is too great, a decision-making process is done to determine if, when, where and how the pest will be managed. An IPM program includes all potential pest control strategies but focuses on non-chemical controls whenever possible, in order to maintain the natural ecology and health of a landscape.

IPM has been practiced in Seattle Parks since the late 1970s and is our standard operating procedure in all landscapes, forests, golf courses and greenhouses. Parks’ landscape management integrates with pest management strategies. An IPM program begins with attention to plant care and culture, as healthy plants resist pests. When pests are observed, the park use and landscape asset value is considered in determining an injury threshold for the particular pest. This philosophy allows staff to respond to both continuing pest issues and also new, unique or specific pest problems.

Parks IPM program includes cultural, mechanical, biological and chemical control methods. For example, cultural could mean planting the right plant in the right place, mechanical might mean hand-weeding, biological could be insect predators or bacterial products for mosquito control, and chemical might be a synthetic or naturally derived herbicide such as Round-Up or vinegar products.

The most common pesticides used in outdoor parks are herbicides for weed control on hard surface cracks, in gravel areas and in shrub beds, while fungicide use for disease is often necessary on golf greens. Insect pests and diseases are common in the artificial growing conditions found in Parks greenhouses, where both insecticides and fungicides could be used.

An IPM program considers the anticipation of potential pest problems to be the most important tool in pest management. Parks staff is trained, knowledgeable, landscape maintenance professionals who understand the plants cultural needs and the potential for pest impacts. Staff monitors landscape assets continuously in their daily work. Each park facility is unique, which allows for determination of the appropriate limits for aesthetic and economic injury. If impacts or injury is imminent and unacceptable, a specific IPM strategy will be designed and implemented. Staff evaluates the success of the strategy over time and makes adjustments as needed for long-term successful pest suppression and management.

Parks horticultural and grounds maintenance staff share responsibility for managing pest problems for 11% of the City’s total land area. Staff who apply pesticides are required to have a Washington State Public Pesticide Operator’s license and attend continuing education classes in IPM on an annual basis to update their skills and knowledge in pest management.

The department also employs an IPM Coordinator who monitors overall programs, and insures that regulatory requirements are met, including tracking pesticide use. This coordinator works with staff to research and develop new pest management strategies, especially regarding alternatives to pesticide use. The Coordinator also sits on the City of Seattle’s Interdepartmental IPM committee, which reviews programs annually and makes adjustments to procedures and protocols. Park’s IPM Coordinator is the department’s liaison on pest management issues to a variety of stakeholders, including the Mayor’s office and the community.

By implementing IPM, Parks has consistently reduced its pesticide use since the late 1970’s. This has resulted in an estimated 80% drop in labor hours associated with pesticide applications. (Previously, pesticide application was tracked in labor hours. Today it is tracked in amounts applied.) In 1999, as part of a commitment to manage public land in an environmentally responsible manner, the city developed Pest Reduction Strategy Goals to reduce use of pesticides overall and to phase out use of the most potentially hazardous products. In 2010, Parks is proud of its IPM program and has reduced its use of pesticides by implementing alternative strategies. For questions please contact Barbara DeCaro, IPM Coordinator - Sustainable Landscapes Programs, at 206-615-1660 or via email