CountyCumberland County
RegionSouthern Maine
EAB quarantineEntire county
Hemlock woolly adelgidEstablished
Tree Medics protects trees for homeowners, businesses and municipalities in Portland and across Cumberland County. We diagnose tree problems and treat the insects and diseases threatening Southern Maine’s trees, from emerald ash borer to browntail moth.
What’s threatening trees in Portland
Emerald ash borerEmerald ash borer was first confirmed in Portland, Maine’s “Forest City,” in 2019.[1]
Hemlock woolly adelgidAs of December 2024, the Maine Forest Service lists it as established in Portland.[2]
Browntail mothFound in all 16 Maine counties, and its toxic hairs stay in the environment for up to three years.[3] In 2026, Maine CDC reported higher browntail moth populations in parts of Cumberland County, along with parts of Androscoggin, Hancock and Oxford counties, even as populations statewide have been steadily decreasing over the past couple of years.[4] The Maine Forest Service’s 2026 aerial survey found localized defoliation mainly along the western shores of Sebago Lake.[5]
Beech leaf diseaseNow found in all 16 Maine counties.[6]
About Portland’s trees
Local landscapePortland is a Cumberland County city with a 2020 Census population of 68,408 and a land area of about 21.5 square miles.[7]
Emerald ash borerIn October 2019 an adult emerald ash borer was confirmed on a trap in Portland, a city whose inventory then listed just over 600 ash trees along streets and in public parks.[8]
Emerald ash borerThe October 2019 Portland emerald ash borer find came from a beetle trap in Payson Park.[9]
Browntail mothIn June 2021 Portland posted browntail moth warning signs in Deering Oaks Park after finding nests in more than 300 trees.[10]
Hemlock woolly adelgidOn May 29, 2014, about 1,000 predator beetles were released in Portland’s 32-acre Baxter Woods to fight a hemlock woolly adelgid infestation, alongside chemical treatments overseen by the city arborist.[11]
Community treesPortland is listed by the Maine Forest Service as a Tree City USA community with 43 years of recognition.[12]
Community treesIn May 2023 the Portland Parks Conservancy received a $12,000 Project Canopy grant to develop an urban forestry management plan for the city’s tree canopy.[13]
Beech leaf diseasePortland was one of four 2026 Maine Forest Service treatment trial sites for beech leaf disease, along with Bowdoin, Etna and Vassalboro.[14]
Tree care services in Portland
Emerald Ash Borer
Trunk injections that protect ash trees from emerald ash borer.
Emerald Ash Borer in Portland
Hemlock Woolly Adelgid
Systemic treatment to keep hemlocks healthy.
Hemlock Woolly Adelgid in Portland
Tree Health Assessments
Find out what’s wrong with a tree and what to do about it.
About tree health assessmentsBrowntail moth season starts in your trees right now.
From October to March, young browntail moth caterpillars overwinter in silk webs at the tips of branches. The Maine Forest Service recommends clipping and destroying webs within reach between mid-December and early April.[15] Browntail moth help in Portland.
A year of tree care in Portland
- WinterClip browntail moth webs, assess trees while branches are bare, and plan spring treatments.
- SpringTrunk injections for ash trees after leaf-out, and browntail moth treatment before caterpillars feed.
- SummerWatch for thinning crowns on ash and early leaf drop. Check beech leaves for dark bands between the veins.
- FallLook for white woolly masses on hemlock twigs, and spot new browntail webs once leaves drop.
Nearby towns we serve
Sources
- Maine DACF: Emerald ash borer discovered in Portland, Maine’s “Forest City”
- Maine Forest Service: Hemlock woolly adelgid overview and distribution
- Maine CDC & Maine Forest Service: Browntail moth hairs pose risk during spring outdoor activities
- Maine CDC Health Advisory: Browntail moth (May 2026)
- Maine Forest Service: Forest & shade tree conditions, August 2026
- Maine Forest Service: Forest & shade tree conditions, September 2026
- U.S. Census Bureau: QuickFacts, Portland city, Maine (2020 Census)
- Maine DACF: Emerald Ash Borer Discovered in Portland, Maine’s “Forest City” (2019)
- Maine Public: Beetle Connected To Ash Tree Deaths Found In Portland (2019)
- WGME: Communities take action as browntail moth population spreads in Maine (2021)
- Portland Press Herald: Adelgids, leash laws under attack in Portland’s Baxter Woods (2014)
- Maine Forest Service: Project Canopy – Tree City USA
- Maine DACF: 2023 Project Canopy Grants Announced (2023)
- Maine Forest Service: Forest & Shade Tree – Insect & Disease Conditions for Maine, August 3, 2026 (2026)
- Maine Forest Service: Browntail moth management overview