City Council stepping up the fight against European Elm Scale


    Elm Scale

    City Council addressed the urgency and importance of fighting European Elm Scale, June 13, by allocating additional funding and resources to combat the pesky insects infecting much of the city’s elm population.

    City staff will treat about 1,000-1,200 infected trees – rather than 600 as originally expected. In addition, City Council has committed $380,000, funded through Council contingencies and Environment Committee, to purchase pesticide and secure the contract services needed to treat approximately 2,400 more public trees. These elm tree treatments are expected to take place over the next six weeks bringing the total public trees treated to approximately 3,600.

    European Elm Scale is an insect that attacks a variety of elm trees. These insects feed on the trees and produce a large amount of honeydew (a sticky secretion) which eventually covers the leaves and bark in a black mold. Heavy infestation can kill weakened trees and cause branch dieback in healthy trees.

    “Protecting our city’s elm trees is important to council and many residents have told us over the last several weeks that it’s important to them as well,” says Mayor Chris Spearman. “One of Council’s strategic goals is to take a leadership role in the protection and preservation of our natural environment. By dedicating new resources and putting our best effort forward to prevent the spread of European Elm Scale, we are doing just that.”

    There are approximately 5,500 elm trees on City property. Some are too small to treat and will be washed instead. Others are not infected. It’s expected that this intensive strategy will address the majority of infected public trees.

    European Elm Scale was first detected in Lethbridge in 2005. The Parks department was able to control the spread until a marked increase in 2012. A combination of factors over the last several years including warmer winters, hot dry summers and a lack of treatment product has now contributed to a serious infestation across the city.

    To date, the City of Lethbridge has been assessing public elm trees to identify those most in need of care. Sixty thousand dollars has been spent over the last few weeks for Parks technicians to inject approximately 600 elm trees with TreeAzin, the product used to combat European Elm Scale.

    “This is an aggressive plan to quickly address the Elm Scale issues our city is facing,” says Councillor Jeffery Coffman. “What we can’t stress enough is the importance of residents being aware and diligent in treating their own trees, as well. Even if we treat all of the trees on City property, if those on private properties aren’t treated, we won’t be able to stop the spread. It’s critical that property owners help us in fighting Elm Scale.”

    For more information on the signs and symptoms of Elm Scale and what you can do to protect your trees visit It is estimated that there are 11,000 elm trees in Lethbridge. Approximately half of them are on public property.

    If an elm tree on your property is showing signs of stress from European Elm Scale, contact a qualified arborist who can administer a pesticide injection. If you have an elm tree on your boulevard that needs attention please, email [email protected] or call 403-320-3850. These trees will be added to the City’s database and evaluated throughout the summer.


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