Pests, Disease, and Invasive Threats

This page offers information on commonly known and emerging threats to town trees. Information is provided from a variety of resources including the Arbor Day Foundation, local tree specialists, CT Agricultural Experiment Station (CAES), UCONN Cooperative Extension, Universities,  as well as area conservation organizations and news outlets.


Purchase ONLY local firewood to help stop spread of disease.


Spring Health & Safety Checkup

Arbor Day Foundation Tree Health Issue page

Bartlett Tree Experts Top 10 Diseases and Insects


Emerald Ash Borer

Emerald Ash Borer Fact Sheet

Spotted Lantern Fly Population in Fairfield

Spotted Lantern Fly Fact Sheet & Management Guide

Hemlock Woolly Adelgid Fact Sheet

Hemlock Woolly Adelgid in Mianus River Gorge

UCONN Pest Identification Diagnostic Services



Invasive vines are strangling many of our trees. Porcelain berry is likely one you are familiar with and may not realize how destructive it can be.

CT Invasive Plant Working Group on Porcelainberry

List of Invasive Plants in CT 

Woody Vines Identification Guide





Diseases can be caused by a variety of organisms including bacteria, viruses and most commonly, fungi. Chestnut Blight and Dutch Elm are well known diseases which have devastated their respective tree species.

Beech Leaf Disease

Anthracnose (fungal) tree diseases in CT

Oak Wilt

Verticillium wilt ornamental trees and shrubs


If you have a concern and/or resource information to share please email us.