New cases of Dutch elm disease identified in Saskatoon

The City of Saskatoon Parks Department has confirmed new positive cases of Dutch elm disease (DED) in three elm trees in the Montgomery neighbourhood, two cases in Riversdale, one in Caswell Hill and cases also in City Park and Sutherland.

The City has initiated its DED Response Plan, which includes:

• Immediate removal of the positive tree(s) and disposal at the City landfill 
• Increased surveillance of the surrounding area to search for stored elm wood 
• Sampling of symptomatic trees within one kilometre of the infected tree 
• Continuing regular elm surveillance and cyclical pruning of trees in parks and on boulevards

In addition to the confirmed DED cases, the City is proactively removing two symptomatic trees in Caswell Hill and Queen Elizabeth. Parks staff will be performing stored elm wood sweeps in a 1km radius around confirmed DED cases. Staff have already conducted several pro-active sweeps for stored elm wood in various neighbourhoods with over 4000 kg of wood seized so far this season.

What will happen in impacted areas?
Parks staff will be conducting surveillance around impacted areas. Surveillance of these areas includes checking every property for elm firewood or brush and removing it when it is found. If residents are not home, staff will remove the elm wood and leave an Elm Infraction Notice with a note indicating that the wood was removed.

As part of the Forest Resource Management Act, the Provincial Dutch Elm Disease Regulations, 2005 allow 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. 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.

How can DED be prevented?
You can help prevent Dutch elm disease by: 
• Never storing elm wood or branches. Don’t buy or take elm wood from anyone and don’t burn it.
• Following 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 wood at the Saskatoon 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. Disposal of elm wood at the Landfill is free.

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.

For more information on DED, visit saskatoon.ca/dutchelmdisease.