Dutch Elm Disease

Elm trees, branches and firewood are attractive to an insect that spreads Dutch elm disease, a disease that kills elms and spreads rapidly.

In recent years, Saskatoon has confirmed several positive cases of Dutch elm disease (DED). As part of the City's aggressive DED Response Plan, infected trees are immediately removed and disposed of at the City Landfill. Surveillance and testing of symptomatic elm trees continues throughout the city. 

Saskatoon’s DED Response Plan

• Immediate removal of all positive trees
• Disposal of infected trees at the City landfill
• Sampling of adjacent trees
• Surveillance and testing of private and public trees in the surrounding area with an intensive search for elm material and other sources of infection. 

The Forest Resource Management Act, the Provincial Dutch Elm Disease Regulations, 2005 allows inspectors to enter private property to inspect for elm wood, remove elm wood and sample private elm trees. In accordance with the regulations, property owners will be asked to remove and dispose of infected elm trees. 

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.  

How is DED spread?

In Saskatchewan, the disease is spread by several species of elm bark beetles. These beetles can fly farther than two kilometres in search of elm trees. The DED fungus has tiny spores that stick to the body of the beetle. Elm bark beetles can carry these spores and infect other elm trees. The fungus can also be spread through root grafts between trees and by infected pruning tools. 

What does DED look like?

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. Residents who start to notice any of these symptoms, are encouraged to complete the online form below or call Urban Biological Services at 306-975-2890.

How can DED be prevented?

Residents can help prevent the spread of DED by:

• Never storing 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).
• 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 in elm trees, as the nail and screw holes can attract elm bark beetles
• Reporting dead or dying elm trees or branches to the City or to a professional arborist

The most effective management strategy for DED is to not transport or store elm wood. It is imperative that elm firewood not be used at any time. It is illegal and threatens the elms that make up 25% of our urban forest.

What does an elm tree look like?

From a distance, the American elm is one of the easiest trees to identify. The trunk is quite straight and often flares at the base. It forks into a few large, ascending limbs which divide repeatedly into fanning, drooping branchlets, forming a graceful umbrella shaped crown. For more information on identifying elm trees and elm wood, refer to the  Elm Identification Handout.

For more information on DED:

SOS Elm Coalition

Canadian Food Inspection Agency - Dutch Elm Disease

Saskatchewan Ministry of Environment - Dutch Elm Disease

Need help with tree identification?
To request a tree inspection or identify elm wood, please complete the online form below or call Urban Biological Services at 306-975-2890.