invasive plants

Below are the presentations and video (unfortunately Matthew Aiello-Lammens presentation was not recorded)  from the Invasive Plant Management Workshop on March 20, 2024

Challenges in protecting and managing urban and suburban landscapes by Matthew E. Aiello-Lammens, PhD

Habitat restoration and public engagement in NYC by Kristy King

Harkness Park Restoration - Blind Brook High School’s Roots and Shoots Club

Early Detection and Rapid Response to Invasive Species in Westchester County by Taro Ietaka

Invasive Plant Management Workshop Presentation Video

An invasive plant is one that has a negative impact on the habitat in which it becomes established. New York State defines an invasive species as “a species that is nonnative to a particular ecosystem, and whose introduction causes or is likely to cause economic or environmental harm or harm to human health."

Many invasive species are not native to Westchester, originating from Asia, Europe, or other parts of the United States. They dominate areas where they become established. They are commonly found along roadsides, the edges of lawns and forests, in open areas, and in many other areas where native vegetation has been disturbed. Some invasive species, such as Burning Bush, Japanese Barberry, and English Ivy, are often sold as ornamental plants for use in landscaping. In the section entitled Additional Resources below is a link to the New York State Department of Environmental Conservation list of prohibited and regulated invasive plant species.

Avoid Planting Invasives
General Resources
On-site Training
In-depth Resources
Introduction to Invasive Species

Non-native invasive plants, whether accidentally introduced or purposefully used in gardening, aggressively push out native species because there are no naturally occurring predators, insects or diseases to control their populations.

If invasive plants are growing around your home, removing them can help prevent them from taking over your yard or spreading further. It is important to recognize invasive species and avoid planting them, because when they “escape” from gardens, they may alter the natural ecosystem.

Invasive species removal is extremely important to the biodiversity in Westchester. Each individual species has its own best management practices. We encourage hand removal of these species and stress the use of chemicals as a last resort in controlling invasive species. Although herbicides can be applied to leaves and stems during the active growing season or to the surface of a cut plant immediately after cutting, be certain to follow manufacturer’s directions or defer to the expertise of a licensed applicator, especially when using herbicides near a water source. It is important to note that while a homeowner may use herbicides on their own property, application on public property or on someone else’s property is only permitted if the applicator is licensed by New York state.

Avoid Planting Invasives

The introduction of invasive species within Westchester County and throughout the United States threatens the balance and resiliency of our ecosystems. The problems caused by invasive species lead to ramifications that extend far beyond the reaches of our forests, waterways, and open spaces. In fact, the environmental degradation caused by invasives affects our own health and well-being and that of our economy at large.

The most foolproof way to prevent the introduction and proliferation of invasive plant species is to avoid planting them in the first place. In September 2018, Westchester County Executive George Latimer signed an Executive Order to protect Westchester’s native plants. The order strictly prohibits the installation of invasive plant species on any County property and encourages the use of native plants instead.

Westchester County residents can apply the same principles to their own properties. Before planting anything new in your yard, verify that the species is not invasive. The Lower Hudson Partnership for Regional Invasive Species Management has a useful database for determining invasive classification.

Opt for incorporating native plants into your landscaping plans whenever possible. Native plants are species that naturally occur in this region and that have evolved over thousands of years to thrive in our area’s specific climate and soil conditions. Not only are native plants just as attractive as ornamental varieties, they often require less maintenance and provide critical food and habitat to our native wildlife and pollinators.

The National Wildlife Federation provides listings of native plants specific to your ZIP code via their online tool. There are many sources from which to purchase native plants. The Native Plant Center in Valhalla conducts an annual sale each spring and many area nurseries carry a variety of native plants that are garden-friendly.

See Native Plants for comprehensive coverage of native plant lists, sources, and best practices.

Section III lists the top invasive species in this region along with tips for identifying that specific species (including possible lookalikes) and best methods for removal. We strongly recommend non-chemical solutions for removing the invasive species when possible. 

General Resources

In this section one can find general resources about invasive plants.

Sponsoring Organization: IMapInvasives
Description:A user friendly, GIS-based database and resource that both stores and records real time sightings and distribution measurements of invasive species. Its information can be easily accessed by citizen scientists and professionals alike in the field using any kind of smartphone device. Download the free mobile app on your phone and within minutes you are ready to photograph and pin vital observations to a map that will help notify others about the spread of non-natives in their area. Records are reviewed by experts and peers to verify species located.

Sponsoring Organization: iNaturalist
Description:iNaturalist is an application that helps you identify the plants and animals you observe in nature. You can record and share photographs of your observations with a global community of scientists and naturalists. Your observations will become part of a database that scientists working in various environmental fields can use for research. There are easy to follow tutorials on how to use iNaturalist.  iNaturalist is a joint initiative by the California Academy of Sciences and the National Geographic Society

Title: Seek by iNaturalist
Sponsoring Organization: iNaturalist
Description: Seek is an application that helps identify wildlife, plants, and fungi, with the use of your mobile device camera while out in the field. This application uses image recognition technology to learn about the organisms around you.

Title: Lower Hudson Partnership for Regional Invasive Species Management (PRISM)
Description: The Lower Hudson Partnership for Regional Invasive Species Management (PRISM) is a cooperative partnership between environmental organizations and individuals who aim to protect the Lower Hudson region from the negative effects of invasive species. Together, the LHPRISM partners  and participants work to protect the biodiversity and ecosystem services of the nine counties and boroughs which make up the Lower Hudson region through a collaborative and integrated approach to invasive species management. They meet regularly to plan strategies to educate about invasive species and work to manage their introduction and spread. They conduct training sessions and organize internships and volunteer programs.

On-site Training Opportunities

There are several organizations within the County that are searching for volunteers to help combat invasive species, and train the volunteers regarding the best methods to try to eradicate them.&

Westchester Parks Foundation
Westchester Parks Foundation engages the public to advocate for and invest in the preservation, conservation, use and enjoyment of the 18,000 acres of parks, trails and open spaces within Westchester County Parky system. WPF hosts invasive species volunteer projects and on-site training opportunities. E-mail address is   and phone number is (914) 231-4600

Bronx River Parkway Reservation Conservancy
The Bronx River Parkway Reservation Conservancy is an advocate for the protection and preservation of the nation's first public parkway. The Bronx River Parkway Reservation Conservancy links concerned citizens with the Westchester County government, which owns and maintains the road, pathway and extraordinary parkland that was created over 80 years ago. BRPRC hosts volunteer projects offering on-site training opportunities.
E-mail address is .

Jay Heritage Center (JHC) is dedicated to transforming the 23-acre Jay Estate in the City of Rye into a vibrant educational campus, hosting innovative and inclusive programs about American History, Social Justice, Architecture, Environmental Stewardship and Landscape Conservation. E-mail address is .

In-depth Resources 

To learn even more about combating invasive species, or the problems they cause, these resources provide further detail.

Title: Managing Common Invasive Species in Home Gardens
Channel/author: Ann Barry of Cornell Cooperative Extension, Rockland County (but talk focuses on Westchester County) Sponsoring Organizations: Jay Heritage Center, LHPRISM, Cornell Cooperative of Rockland County, Hudsonia, Little Garden Club of Rye, Rye Garden Club, and the Sustainability Committee of Rye.
Description: One hour, 26 minutes. Master Gardener Ann Barry provides engaging, informative video introduction to common invasive plant species often found in Westchester gardens, including Norwegian Maple (also known as Norway Maple), Porcelain Berry, Burning Bush, Multiflora Rose, Oriental Bittersweet, Wineberry, Mile-a- Minute, Purple Loosestrife, Black Swallowwort, Garlic Mustard, Japanese Angelica, Japanese Stiltgrass and Japanese Knotwood. Topics include how to recognize, control, eradicate and replace invasives with native plants, with visuals, including photographs.

Title: New York State Prohibited and Regulated Plants
Author/Source: NYS Department of Environmental Conservation and NYS Department of Agriculture and Markets
Description:  Q&A on invasive species, with photos of prohibited and regulated NYS invasive species, including terrestrial, wetlands and aquatic species.

Title: "Bringing Nature Home: How You Can Sustain Wildlife with Native Plants," Updated and Expanded Edition 
Author: Douglas W. Tallamy
Publication: Updated Edition, 2009 (Timber Press)
Description: How incorporating native plants into your residential landscaping will attract native wildlife and help slow declines in their populations; includes information on invasive species of the Mid-Atlantic Region, their destructive effect on local ecology, and the difficulty of eradicating them.