Tree with Beech Leaf Disease Found in West End of Cobourg

Cobourg, ON (May 29, 2026) – The Town of Cobourg would like to notify residents that earlier this week a tree with Beech Leaf Disease was found in the west end of Cobourg on private property.

There is no sign any Town of Cobourg beech trees have been affected at this time. Trees will
be monitored and assessed by the Town’s Urban Forestry Department.

About Beech Leaf Disease
Beech Leaf Disease (BLD) was first detected by the Canadian Food and Inspection Agency (CFIA) in Ontario in 2017 where the disease was present in Elgin County. BLD is caused by an invasive worm-like parasitic nematode, Litylenchus crenatae ssp. Mccannii. Nematodes are microscopic worms that feed on developing buds in the fall and spring, disrupting normal leaf development. During the summer months the nematodes feed on leaf tissue between veins.

Disease Impact
Young trees are highly vulnerable to disease and mature trees can also be severely affected by BLD. BLD does not pose a direct threat to human or animal health, however ecological impacts caused by increased death in Beech trees may impact forest dwelling animals’ natural food chain.   

Signs of Infection
Infected Beech trees may show early symptoms such as dark green stripes or bands between lateral veins of leaves. Severe symptoms include leaves dropping early, buds not developing, reduced leaf size, thickened or leathery leaves, yellow leaves, and curled or deformed leaves.

Species Impacted
American Beech (Fagus grandifolia), European Beech (Fagus sylvatica), Oriental Beech (Fagus orientalis), and Chinese Beech (Fagus engleriana).

For further information on BLD visit the following websites:

• Beech leaf disease | ontario.ca
• Beech leaf disease (Litylenchus crenatae mccannii Carta, 2020) - EDDMapS
• Beech leaf disease – Invasive Species Centre

Prevention
If you have any questions, or suspect a tree on your property or Town property has been infected, please contact the Urban Forestry Department by phone or email:

T: (905) 372-8641 x 4369
E: trees@cobourg.ca

If you suspect a Beech tree on your property has BLD, please do not move Beech seedlings, leaf litter or firewood to prevent unintentionally spreading the invasive nematode.