August 1, 2026
The City of Edmonton has confirmed four new cases of Dutch elm disease (DED) as two trees in the Glengarry neighbourhood and two trees in the Rossdale neighbourhood have tested positive for the disease. There have been 14 total cases of the disease confirmed in Edmonton since it was first detected in 2024.
The trees were identified by City crews through a visual inspection. Test results confirmed the disease, and the trees will be removed as part of the ongoing efforts to contain the spread of the deadly fungal disease. Prompt tree removal is essential to maintaining the health and safety of the urban forest.
All four trees are within the current DED Protocol Zone and the zone boundaries will be adjusted to include a one-kilometre radius around these new locations. The protocol zone is established in areas where DED has been confirmed to allow for heightened monitoring, assessments and tree maintenance.
Dutch elm disease is a contagious fungal infection that spreads easily to nearby elms. The disease poses a significant threat to Edmonton's urban forest, where elm trees make up 22 per cent of the City’s Open Space and Boulevard Tree Inventory, or approximately 90,000 in total.
Promptly removing infected trees and any elms within 20 metres, alongside a diligent pruning program to clear deadwood, is necessary to reduce habitats for the beetles that spread the fungus.
All pruned elm wood is disposed of at the Edmonton Waste Management Centre, following strict, specialized handling procedures.