Westchester County NY Government

The species of trees that have evolved in any particular region are referred to as “native” trees and are an important part of the local ecosystems. Healthy ecosystems clean our air and water, maintain our soil, help regulate the climate and provide us with food. For the purposes of this website, trees considered “native” to the Northeastern U.S.A. are those that were here before European settlers arrived. Many popular trees, while attractive, are not native to this region and provide little to no support to the wildlife in our region. Native trees support our local insects, birds, and animals; are adapted to local weather conditions; provide a unique natural heritage to Westchester County, and are critical to the health of our ecosystem.

Title: Homegrown National Park – Tallamy’s Hub
Sponsoring Organization: Homegrown National Park
Description: Doug Tallamay is a preeminent Professor of Entomology and Biology at the University of Delaware. This website provides access to many of his talks and articles which detail why it is critical to our health and well-being that we plant native trees.

Do not plant invasive trees
An "invasive” species is one that is not native to the ecosystem under consideration; and whose introduction causes, or is likely to cause, economic or environmental harm or harm to human health. Please do not plant any non-native, invasive trees.

There are a few tree species that were imported to Westchester years ago that have actually harmed the local ecosystem. For example, the Norway maple (Acer platanoides) was planted along streets in Westchester for decades to replace the American elms (Ulmus americana) that were decimated by Dutch elm disease. Norway maples can tolerate the harsh conditions of the urban landscape, such as road de-icing salt. Due to its successful growth and reproduction, however, the Norway maple has invaded our woodlands to the point of outcompeting our native trees and damaging the local ecosystem. It is now referred to as an “invasive” tree species and New York State now regulates planting of Norway maples, as well as other invasive plants.

Read more about Combating Invasive Species.

In 2015, the New York State Department of Environmental Conservation implemented rules prohibiting and regulating invasive species in New York to help control invasive species by reducing their introduction and spread. The regulations list what tree species you should not plant. (NYCRR Part 575).

Title: New York Invasive Species Regulations
Sponsoring Organization: NYS Department of Environmental Conservation
Description: This resource lists which trees one should not plant. It also lists other species such as other plants, fish, etc. of which New York prohibits introduction. It contains all the information you need to understand the current invasive species regulations in NYS.

Westchester is also in the Lower Hudson Partnership for Regional Invasive Species Management (Lower Hudson PRISM) that monitors and manages invasive species throughout the region. Think of Lower Hudson PRISM as your “neighborhood watch” for new invasive species and managing current infestations. Learn more about the Lower Hudson PRISM.

Title: Species Information
Sponsoring Organization: Lower Hudson PRISM
Description: List of all invasive and potentially invasive species in the Lower Hudson region that is updated annually by Lower Hudson PRISM Partners annually.

For your convenience, below is Lower Hudson PRISM’s list of invasive trees that should NOT be planted in Westchester County.