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Integrated Pest Management

A photo of the Pesticide Free Park sign at Arbor Lodge Park.
The mission of the PP&R Integrated Pest Management (IPM) program is to manage pests that are harmful to the health, function or aesthetic value of park landscapes in an efficient, effective, and environmentally responsible manner, while paying careful attention to public and employee safety.
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To best manage pests in park lands, PP&R personnel utilize the principles of Integrated Pest Management (IPM).

On March 2, 1988, Portland City Council passed a resolution that directed Portland Parks & Recreation (PP&R) to “adopt and begin implementation of a grounds maintenance policy embodying the principles of Integrated Pest Management. The mission of the PP&R Integrated Pest Management (IPM) program is to manage pests that are harmful to the health, function or aesthetic value of park landscapes in an efficient, effective, and environmentally responsible manner, while paying careful attention to public and employee safety. To accomplish this, the principles of Integrated Pest Management are utilized. This progressive and sustainable approach uses multi-faceted strategies that minimize economic, health, and environmental risks.

Integrated Pest Management strategies
There are several levels of strategies that are a part of Integrated Pest Management.

Protecting our assets

Portland Parks & Recreation is part of the City of Portland and stewards of more than 11,500 acres of land at over 250 locations including regional, community, and neighborhood parks, natural areas, recreational facilities, special gardens, and trails. These parks contain over 2.2 million square feet of developed shrub beds, six botanic gardens including three specialty rose gardens containing 20,000 roses, 1,360 acres of turf with 365 athletic fields, five 18-hole golf courses, and over 7,000 acres of natural areas. These parks also offer a wide array of recreation and enrichment opportunities for people of all ages. Portland Parks & Recreation is charged with maintaining these diverse park landscapes in a safe, attractive, healthy, and useful condition. Park properties represent a major component of the city’s capital assets and PP&R recognizes its responsibility to protect and preserve this economic investment to the best of its abilities. PP&R also recognizes its responsibilities to its employees, park users, and the general public, and seeks to employ the highest professional standards. To best manage pests in park lands, PP&R personnel utilize the principles of Integrated Pest Management (IPM).

Pesticide Certification Courses

Thank you for participating in Portland Parks & Recreation pesticide re-certification courses! All registration and payments can be made online by clicking here!

If this is your first time accessing PP&R's online registration, you'll need to create an account. If you need assistance, check out this video on how to create an account. If you are registering for multiple people, you can add “family members” to your account for employees or friends who also want to register for the course. Once you have created your account, search for Pesticide Applicators License Recertification - 1087562, and follow the steps. 

For questions in regards to registration, please contact 503-823-2525.
For program questions, call 503-823-1991.

Pesticide Applicators License Recertification Links

Application for Pesticide Use on Park Land

All pesticide applications taking place on park land carried out by non-PP&R personnel, must undergo a special approval process to satisfy certain licensing and other requirements before the work can take place. This oversight is essential to ensure that all pest management activities occurring on park land adhere to established IPM-based goals and principles and address environmental and safety concerns. Please download and submit the form below.

About the Integrated Pest Management (IPM) program

Pests in Portland parks may be noxious weeds, invasive plants, problem insects, plant diseases, rodents or other organisms that cause problems in the landscapes under our care. Our trained and licensed PP&R employees respond to these pests by using the modern principles of integrated pest management (IPM) and invasive plant control.

An Integrated Pest Management program for Portland parks has been in place since the late 1980s. The policies in this program direct every aspect of pest management in our parks, and they serve as rules for all pest management personnel. Updated continuously to respond to new information and new challenges, our program has been hailed as a model of progressive methods and practices by other municipalities and agencies throughout the region. The PP&R program meets or exceeds local, state, and federal requirements.

Integrated Pest Management (IPM) FAQ's

What is Integrated Pest Management (IPM)?
IPM first determines if a pest needs to be managed, and if so, when, where, and how best to do it. Key elements of an IPM program include gathering information up front as well

as monitoring results. IPM uses many strategies to achieve its goals, combining policies, cultural practices, mechanical means, and biological and pesticidal methods. The IPM process ensures that the most effective, low-risk methods and materials are used to manage pests. Here are a few examples of IPM in Portland parks:

  • Mulching planting beds to prevent new weeds;
  • Mowing high grass and brush to reduce weed seed crops in low maintenance areas;
  • Pruning plants to increase air circulation helping to suppress some diseases;
  • Using the correct fertilization to encourage plant health and pest resistance;
  • Using plants with natural pest resistance;
  • Aerating and overseeding turf to encourage healthy grass; and
  • Applying carefully selected herbicides to control weeds before they can see

Why do we need IPM in our parks?
IPM makes it possible to responsibly care for the 250 parks and recreational sites in our system, totaling over 11,000 acres. Portland's parks are a multi-billion dollar asset and include over 2.2 million square feet of developed shrub beds, three major rose gardens, five championship golf courses, and thousands of acres of natural area. Keeping our plantings healthy, our landscapes well maintained, and our natural areas in ecological balance requires an IPM program. IPM is especially important for PP&R since we have to care for so many acres, a limited number of people to do so, and high standards of safety and environmental protection.

Who manages pests in Portland parks?
The cornerstone of Portland Parks & Recreation's (PP&R's) IPM program is our trained staff--including horticulturalists, ecologists, technicians, and specialists. Their understanding of plant and landscape needs makes decision-making about which IPM option to use in individual cases possible. PP&R's policies require that personnel who apply pesticides of any kind are required to maintain an Oregon Public Pesticide Applicators license--administered by the State of Oregon. To keep this license, they are also required to attend continuing training and education where they learn about the latest pest management techniques and materials. Our licensing requirements exceed state and federal standards. PP&R is committed to this higher level of training for our applicators. PP&R's IPM Coordinator develops and refines the overall program, and ensures that regulatory requirements are met. The coordinator also researches IPM science, develops pest management strategies, trains staff, and communicates with the public and other bureaus.

On what are IPM decisions based?
When developing and updating our program, we rely on the best expert scientific opinions to inform us about the materials and methods we use. Assessments from agencies such as the Environmental Protection Agency and the World Health Organization are starting points for us, as are state universities. University extension scientists provide a lot of useful information about the latest IPM research. We turn to these recognized experts for trustworthy science-based information. We also follow the latest pertinent studies in IPM. By basing our decisions on these sources, we can arrive at the best solutions within our IPM framework.

How will I know if PP&R applicators are applying pesticides in a park?
PP&R understands that park users may want to be made aware of these treatments, and we have a notification system that goes beyond federal and state requirements. When an area is being treated with any pesticide, the applicator will place signs that include basic information such as the name of the product being used, what is being treated, directions for park visitors, and contact phone numbers to get additional information. Calling PP&R makes it easy to get additional accurate information about the pest problem and other pertinent details.

Is household vinegar an effective alternative to kill weeds in the parks system?
No. Household vinegar (with 5% acetic acid) does not kill the roots or below ground parts of a plant. Further, it is most effective at controlling small, immature plants. Larger weeds and perennial weeds may wilt and discolor after spraying, but may begin to re-grow a week or two later since the vinegar does not kill the root systems. Unless you can apply vinegar early and often, it will not kill weeds. PP&R oversees over 11,000 acres and, unfortunately, we are not always able to target weeds as soon as they germinate and are small. Most importantly, it is illegal for PP&R to use a product as an herbicide or pesticide if that is not its intended purpose per the federal Environmental Protection Agency (EPA). To summarize, household vinegar may be an effective temporary tool for a homeowner in a small area of newly established weeds; but it is no more effective than mowing, and less effective than mulching or hand pulling. And it is not a feasible option for Portland Parks & Recreation to utilize.

Invasive Plants

Invasive, non-native plants are one of the biggest threats to our native ecosystems. Because of their aggressive growth and lack of natural enemies in our region, these species can be highly destructive, competitive, or difficult to control. These invaders compete with native plants in many ways: occupying space, changing the structure of the plant community, causing physical and chemical alterations of the soil, and covering and shading native plants. Invasive plants interfere with animal life, too, by altering the structure of their habitat and by eliminating favored food plants through competition. Invasive plants are spread both by human activity and by animals that eat them and carry their seeds.

Here are some of the species that we are battling in the Portland area:

English Ivy (Hedera helix)
This is an aggressive, invasive, introduced species. With nothing to stop its spread, and its ability to grow in almost any situation, this weed covers ground and climbs trees as it transforms natural areas into ivy monocultures, providing no habitat for native wildlife.

Garlic Mustard (Alliaria petiolata)
One of the most invasive forest understory plants in the East and Midwest, this weed is just starting to establish in the area. This non-native biennial can establish in a relatively stable forest understory. It can grow in shade or sun. Plants can produce more than 62,000 seeds per square meter to quickly out-compete local flora.

Giant Hogweed (Heracleum mantegazzianum)
This huge relative of the carrot is not only an invasive weed, but can cause health problems for those unlucky enough to encounter it.

Kudzu (Pueraria lobata)
This vine can grow a foot a day, smothering all other plants in its path.

Purple Loosestrife (Lythrum salicaria)
A pretty flower, but this exotic weed is anything but pretty when it crowds out native aquatic vegetation destroying valuable wildlife habitat. Plant diversity is needed for birds and other animals to thrive, but this weed can take over an entire wetland. Each plant can produce 2.5 million seeds a year.

Old Man's Beard (Clematis vitalba)
A cousin to our garden clematis varieties, but this one is not well behaved. An invasive climber, this plant can grow 30 feet in a season, and is able to smother large trees. Its fluffy seeds spread far and wide.

Related Links

Protect the Best - Invasive Vegetation Management Program

Portland natural area parks contain ecologically healthy habitat that supports wildlife and provides unique opportunities for people to experience nature locally. Invasive plants such as Himalayan blackberry, English ivy, and English holly displace native vegetation in our natural areas, degrading scenic and ecological diversity. Once these invaders root and spread, it can take years to clean up the habitat, and many more years to re-establish the native plant community. PP&R is testing a new approach to invasive vegetation management, called the Protect the Best Invasive Vegetation Management Program (PTB), aimed at controlling invasive plants before they have a chance to damage our most pristine natural areas.

Protect the Best, initiated in 2007 as part of the Grey to Green Initiative, has the goal of preventing small patches of invasive plants from spreading in PP&R's most ecologically healthy natural areas. Our approach is to identify and treat ecologically healthy "core habitat," then create a relatively invasive-free "buffer habitat" surrounding it, reducing the chance of re-infestation. Worksites are selected primarily based on the ecological health rating assigned in the PP&R vegetation survey (2003-04). PTB staff removes English ivy, English holly, Himalayan blackberry, garlic mustard, and other invasive species using hand tools, chainsaws, and herbicides. Treatments are tracked with GPS and an Arc GIS Database. Since the program began, over 3,800 acres have been treated in numerous parks including Forest Park, Powell Butte, Buttes Natural Area, Maricara Park, and Elk Rock Island. 

Pesticide-Free Parks

In the fall of 2004, Portland Parks & Recreation and the Pesticide-Free Parks partners began a three-year trial of pesticide-free park management at three sites - Lair Hill Park in Southwest Portland, Sewallcrest Park in Southeast, and Arbor Lodge Park in North Portland. During the trial process, no pesticides of any kind were used in these parks. Instead, volunteer work parties weeded by hand, mulched shrub beds, and controlled weeds in other ways. PP&R also continued to use various kinds of integrated pest management methods, such as aeration and overseeding of the park turf. The trial ended in fall 2007.

Two new pesticide-free parks were added to the program in 2008 - Midland Park in Southeast Portland and Hillside Park in Northwest Portland.

Volunteers are critical to the success of the program. To get involved at a pesticide-free park, please contact Volunteer Services at 503-823-5121.

Arbor Lodge Park Quarterly Park Clean-ups, 9:00am-12:00pm. Join neighbors to weed and maintain Arbor Lodge Park. For more info, email Arbor Lodge Neighborhood Association.


Nichole Linehan

Integrated Pest Management Program Coordinator