Dutch Elm Disease

What Is It?

Dutch Elm Disease (DED) is a deadly disease caused by a fungus (Ophiostoma ulmi) that can affect any elm tree. Since its introduction from Europe about 1930, it has destroyed millions of American elm trees across North America.

An isolated case of DED was discovered in Wainwright, Alberta in 1998.

Two elm trees in the City of Lethbridge have been diagnosed with Dutch Elm Disease... for more information please click here.
An elm tree during the summer with yellow leaves
What's the Problem?
Although Alberta is still disease free, the beetles, which carry the disease, have been found in Edmonton and St. Albert (since 1995), Calgary (since 1994), and Vauxhall (since 1996).

On average, DED arrives 3 to 7 years after the first detection of elm bark beetles.
What Can I Do?
Keeping Track of Elm Trees
Monitor the condition of the your elm trees.

Watch for these symptoms of Dutch Elm Disease:
  • Drooping and yellowing leaves in summer
  • Branches with smaller leaves than rest of the tree
  • Branches with no leaves
  • Brown wilted leaves that remain on the tree
Apart from being ideal breeding material for the beetles, elm firewood is especially problematic as it is easily and often transported from place to place. It is in this way that the beetles and DED are most readily transported long distances.

Because DED can be carried on elm firewood, provincial regulations prohibit storage, transport and sale of elm firewood. So if you go camping, please do not transport firewood.

Pruning and Disposing of Elm Wood
Prevention of Dutch Elm Disease starts by keeping elm trees healthy. Prune all dead wood that provides beetle habitat. Pruning of healthy elms, however, should only be done during the winter season when the beetles which are attracted to fresh tree wounds are not active (October 1 to March 31).

Did you know?
Edmonton has one of the largest concentrations of uninfected American elms left in the world.