Dutch elm disease

It is illegal to store elm wood without doing at least one of the following:

Removing all bark from the wood
Treating the wood by kiln-drying it to a moisture content of 18% or less or eating it to 56°C for at least 30 minutes
Chipping the wood to less than 5 cm in all directions
Getting written permission from the Province of Manitoba

It is also illegal to move elm wood for any reason other than disposal. The beetle that carries Dutch Elm Disease lays eggs in intact wood. Moving infected elm wood spreads the disease.

About Dutch Elm Disease

Dutch Elm Disease (DED) is a wilt disease caused by a fungus. The fungus is mainly spread between elm trees by the elm bark beetle.

Young beetles pick up the fungus from diseased elms in late summer. The spores survive on the beetles’ bodies while they hibernate in healthy elm trees over the winter. They are then transferred into the wood as beetles feed on branches the following spring and summer.

Symptoms of DED usually appear in early summer. They include:

Wilting and curling leaves
Yellowed or browned leaves as the disease progresses
Dead leaves that remain on trees rather than falling
Dark brown streaking in sapwood – this can be seen by peeling away the bark on a small branch

The disease can kill an American elm within weeks of infection.

Controlling Dutch Elm Disease

We first detected DED in Winnipeg in 1975.

Our DED control program involves monitoring elms for infection and quickly removing diseased trees.

We inspect all elm trees annually between June and September.
We do not prune elms from April 1 through July 31. This helps prevent the spread of disease.
We conduct our removals from January to April and September to December but removals can take place year round.