Dutch Elm Disease, DED, has yet to take hold in Calgary. The two main reasons for this are our geographical isolation and the diligent work of the city of Calgary's urban forestry team, working throughout the city for over a decade monitoring, inspecting and keeping watch on all of their beetle traps.
A group of beetles, mainly the elm bark beetle, a small boring insect, is the main carrier of a fungus, Ophiostoma ulmi. This disease has changed the face of North American cities throughout the east and has moved west in the last decades. Thousands of beloved stately elms have disappeared from all major eastern North American cities. These cities' elms were all connected because of the great number of Trees and the fact that elms are native throughout the region.
Out west things are different. Planted mainly in western cities, our elms grow in isolated islands of territory with very little connection between. Elms have been used as shelter belt plantings throughout the west but the numbers are small. The island concept has certain advantages. By adhering to a few simple guidelines we may be able to remain disease free.
The beetles who carry the fungus that kills the Trees breed in elm deadwood. This is the reason for the firewood ban. Stored elm firewood has the potential to greatly assist the beetle population. The other place we find elm deadwood is in the Trees themselves. This is why all city elms are being pruned. All elms on private property should also be pruned, should have their dead branches removed.
One symptom of potential infection is the mid season unexplained yellowing of elm branches. If you see an elm acting strangely, make the call. Learn to identify elm trees. Learn where elms grow in your neighborhood and watch them. Once DED gets a hold in Calgary our beautiful elms will need all the friends they can find.
- Learn to identify an elm Tree
- Prune elms on your property
- Don't store elm firewood
- Respect the spring to fall pruning ban, no pruning from Apr. 1 to Oct. 1.
- Inspect elms in your neighborhood; look for yellow branches when they should be green.
- Make the call, phone 311 to report.
The advantage given to our elm population by a informed observant community of people will make all the difference, the difference between having elms in our city or not.