As Certified Arborists, the health and well-being of the trees in our landscape is of utmost importance. One of the most significant and time-sensitive topics in Alberta today is the Elm Tree Pruning Ban, a crucial measure taken by provincial authorities to curb the spread of Dutch Elm Disease (DED).
In this blog post, I’ll walk you through why this ban is so critical, the science behind it, and what homeowners and property managers need to know to ensure their elm trees thrive in the face of this ongoing threat.
The Importance of the Elm Tree Pruning Ban
Dutch Elm Disease is a deadly fungal infection that has devastated elm populations in many parts of the world. Alberta and BC are the last two locations in North America to remain DED free. In Alberta, the government has enacted an annual Elm Tree Pruning Ban, which runs from April 1st to August 31st in order to ward off DED and preserve our beautiful elm trees. (https://www.alberta.ca/agri-news-elm-pruning-ban-starts-april-1)
During these months, pruning or removing any elm trees is prohibited. The rationale behind this ban is based on the life cycle of the smaller European elm bark beetle Scolytus multistriatus, and the native elm bark beetle Hylurgopinus rufipes, which are active during the warmer months and spread the pathogens Ophiostoma ulmi and Ophiostoma nova ulmi, that are responsible for DED.
Why Pruning Can Spread Dutch Elm Disease
The act of pruning elm trees during the active months of the beetle’s lifecycle increases the risk of spreading the disease. When an elm tree is cut, the fresh wound can attract the beetles, which feed on the sap and, in doing so, transfer fungal spores from infected trees to healthy ones.
In short, pruning during the summer months creates an opportunity for beetles to infect healthy trees, which accelerates the spread of the disease across the landscape.
How ISA Certified Arborists Can Help
While the ban is in place to protect Alberta’s elm trees from the spread of Dutch Elm Disease, the role of an ISA Certified Arborist remains crucial in managing the overall health of these trees.
Proper Diagnosis: An arborist can assess whether a tree is healthy or showing signs of disease. Symptoms of Dutch Elm Disease include yellowing leaves, wilting, and visible lesions on the trunk and branches. Catching the disease early is essential, and a professional arborist can help identify problems before they worsen.
Pruning Outside of the Ban Period: Though pruning is prohibited in the summer months, it can still be done safely during the fall, winter, and early spring when beetle activity is at its lowest. A certified arborist will know the right times to safely prune elms and how to avoid spreading disease.
Preventative Measures: Prevention is always better than cure. A well-maintained elm tree that is properly watered, mulched, and fertilized will be better equipped to resist diseases.
Tree Removal and Disposal: If Dutch Elm Disease has already taken hold, it’s critical to remove and properly dispose of infected trees in accordance with provincial regulations. Diseased material should be chipped, burned, or buried to prevent beetles from using the dead wood as a breeding ground.
What Homeowners Need to Know
If you own an elm tree in Alberta, it’s important to be aware of the pruning ban and adhere to it. If you are uncertain about the health of your tree or if you need advice, an ISA Certified Arborist is your best resource. They can guide you in the best management practices for your tree, ensure that you are not inadvertently contributing to the spread of Dutch Elm Disease, and help maintain the beauty and health of your trees for years to come.
As a homeowner, you can also take these steps:
Monitor Your Tree: Keep an eye on the condition of your elm tree. If you notice signs of wilting, yellowing leaves, or bark abnormalities, call an arborist immediately for a diagnosis.
Keep the Area Clean: Dispose of fallen branches and leaves properly, especially in the summer months when beetles are most active.
Consult a Professional: Avoid doing DIY pruning during the pruning ban. Always consult an ISA Certified Arborist to ensure the safety and health of your tree.
Conclusion
The Elm Tree Pruning Ban in Alberta runs from April 1 - Aug 31 yearly and is an essential tool in the fight against Dutch Elm Disease. We at Cowboy Trail Tree Service support this measure and encourage everyone to work together in preserving these majestic trees. While the ban prevents pruning during certain months, there are still plenty of steps that can be taken to protect the health of your elms. Regular inspections, proper tree care, and professional advice are the best ways to ensure that your elm trees remain strong and disease-free.
By following the guidelines and relying on the expertise of certified professionals, we can all do our part in preserving Alberta’s beloved elm trees for generations to come.
Stay safe, and happy tree care!
Lisa Sullivan B.Sc.
ISA Certified Arborist # PR-4893A
Registered Consulting Arborist # 624
Member, American Society of Consulting Arborists
403-450-3456
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