Dutch Elm Disease in Saskatoon

The City of Saskatoon Parks Department has confirmed a record number of positive cases of Dutch elm disease (DED). These cases are widespread and not concentrated in any particular neighbourhood. In Buena Vista, the majority of our streets are lined with elm trees. As a community, we need to act together to protect the health of our urban canopy.

Residents can help prevent the spread of DED by:

• Never store elm wood or branches. Don’t buy or take elm wood from anyone and don’t burn it.
• Not pruning elms during the provincial pruning ban (April 1 to August 31). Elm bark beetles are attracted to freshly cut wood and are most active during this time period.
• Disposing of elm at the City Landfill. Do not take elm to the compost depot or put it in your green bin. Dispose of it immediately, even if it is during the provincial ban.
• Sanitizing tools after working on elm trees
• Not building treehouses or adhering items to elm trees with nails or screws, these holes can attract elm bark beetles

How to identify and report unhealthy elm trees and firewood
American elm trees with DED may start showing symptoms as early as June. Typically, the leaves will start to wilt and turn yellow, then curl and turn brown. If you suspect an unhealthy elm tree or are unsure of what type of firewood you have, take a photo and complete the online form at saskatoon.ca/dutchelmdisease or call Urban Forestry at 306-975-2890.

What is DED?
DED is a serious disease caused by a fungus that clogs the elm tree’s water and nutrient conducting system, which eventually causes the tree to die. DED was introduced in North America in the 1930s and has since wiped out millions of elms across Canada and the United States. In Saskatoon, elms make up 25% of our urban forest.

How is DED spread?
In Saskatchewan, the disease is spread by several species of elm bark beetles. When beetles emerge from DED-infested wood, their bodies are coated in tiny spores from the DED fungus. As they seek out new trees or firewood to inhabit, they bring along the fungus, helping it spread. The beetles themselves can’t fly very far, so the primary way DED spreads over long distances is through the movement of elm firewood. The fungus can also be spread by contaminated pruning tools.