In June 2024, I wrote an article on the status of Dutch Elm Disease (DED) in Saskatchewan (Pinned to the top of our Facebook page www.facebook.com/saskperennial). Since then, there have been significant changes in the disease progression, with more damage to our trees occurring. A few weeks ago, I was sitting outside a house on Eastlake Avenue, in the Broadway area of Saskatoon, and it struck me how bare and exposed that street would be if all the elms were removed. Elm trees are an ideal shade tree for city streets and were used extensively in North American cities for a hundred years and more, until civic planners realized about 30 -40 years ago that these trees were very vulnerable to the deadly DED. Since then, several different types of trees have been planted in urban streets and parks; unfortunately, many of these seem to have significant disease or insect problems and do not do well in urban environments. On the street where I live, developed in the 1960s, a variety of trees have been planted, as well as the stately elm, which certainly would lessen the impact of destruction of the elms. However, I was horrified a few weeks ago when a city crew began cutting down a large elm at the end of our block. I rushed down to see what was happening and was very relieved when the manager of the crew explained the main trunk of the tree was splitting, making it structurally unsound and a possible danger to houses and people. I counted the rings on the remaining stump and there were at least 50, so that elm was likely planted just after the houses were built on our street.
The Saskatchewan Crop Protection Lab (CPL), based in Regina, has been identifying wood infected with DED, testing samples at no charge for several years. This means the status of the disease prevalence can be monitored in the cities that submit samples. The majority of the city samples have been from Regina, Moose Jaw and Saskatoon. Following are the findings for the last year of testing.
In Regina, 111 of 236 samples were infected with DED (positive), in Moose Jaw, 53 of 91 samples were positive, and in Saskatoon, 43 of 245 samples were positive, resulting in the removal of 62 trees.
An article posted by Phil Tank on CBC News, Feb. 9, 2026, outlines the progress of the disease in Saskatoon:
2015 – first case of DED
2021 – two cases
2023 – four cases
2024 – 11 cases, 18 mature elms removed
2025 – 41 cases (reported as 43 cases by CPL; I do not know why these values are different), 62 trees removed.
It is obvious that the disease is becoming more prevalent each year and the number of trees removed is also increasing. Saskatoon City Hall has stated they anticipate an increasing surge in the number of infected trees. The public needs to recognize possible symptoms of DED: in late June to mid-July, sudden yellowing and flagging of one or more branches at the top of the tree; the leaves wilt, turn yellow (later brown), but stay on the branch. If you notice these symptoms, City management should be informed so that samples can be taken and the tree removed if it is infected with DED. There are other reasons why a tree may look infected, and a laboratory test is required to confirm the diagnosis.
Another important way that disease spread can be reduced is by stopping storage and movement of possibly infected wood. Signs warning the public not to transport firewood around the province have been posted along highways for a number of years. Storage of elm firewood in the city may also help spread transmission of the disease by elm bark beetles. City crews have been looking for, removing and disposing of elm firewood on private properties. The City has also waived the landfill fees for public disposal of elm wood, which helps remove infected wood from the disease cycle.
We all need to be vigilant to help protect the elm trees that contribute so much to the comfort of our city lives.
For more information, or to get a tree inspected, contact – Dutch Elm Disease | City of Saskatoon
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.
