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Dutch Elm Disease Management in Manitoba

Communities throughout our province have planted hardy and beautiful American elms, making effective management of Dutch elm disease (DED) particularly important to Manitobans. Many communities, in cooperation with the Manitoba government, have been successfully managing DED for more than 40 years. This has allowed them to retain mature urban tree canopies that provide valuable benefits, such as wind reduction, shade, wildlife habitat, and cleaner air.

What is Dutch Elm Disease?

DED is an introduced disease caused by a fungus that kills American elm trees. The fungus is mainly spread from elm to elm by native elm bark beetles when they feed in the canopy of elms and overwinter under the bark at the base of the trees. The bark beetles breed in dead and dying elm material including elms infected with DED. For this reason, much of DED management centres on the removal and sanitation of this material.

Diseased elm tree
Diseased elm tree

Background

The Dutch Elm Disease Management Program has been in existence in Manitoba ever since DED was first detected in this province in 1975. The program is administered under The Forest Health Protection Act and Forest Health Protection Regulations (for more information on this legislation please go to: (http://web2.gov.mb.ca/laws/statutes/ccsm/f151e.php).

Presently, the program is active in 38 communities that have significant urban elm populations. The City of Winnipeg manages DED within city limits.

Dutch Elm Disease Management Agreements

Communities participate in the program through an agreement with the province. Under these agreements, the province provides technical assistance and annual surveillance where trained inspectors search for elm firewood and infected elms.

Trees marked by provincial inspectors are removed by the participating municipality. In addition, each of the communities must take measures to protect their elms from DED. These measures include activities such as regular pruning of dead branches from elms that can attract elm bark beetles, basal spraying of an insecticide to elms to reduce elm bark beetle populations, and public education.

The following communities are currently participating in the Dutch Elm Disease Management Program:

  • Altona
  • Arborg
  • Birtle
  • Boissevain
  • Brandon
  • Carman
  • Crystal City
  • Deloraine
  • Dauphin
  • East St. Paul
  • Gimli
  • Gladstone
  • Headingley
  • Killarney
  • Manitou
  • Minnedosa
  • Morden
  • Morris
  • Neepawa
  • Pilot Mound
  • Portage La Prairie
  • Reston
  • Ritchot
  • Rivers
  • Riverton
  • Russell
  • Selkirk
  • Souris
  • Springfield
  • St. Andrews
  • St. Clements
  • Ste. Rose Du Lac
  • Steinbach
  • Stonewall
  • Swan River
  • Treherne
  • Virden
  • West St. Paul

Dutch Elm Disease Surveys

The survey program is managed from the Sustainable Development office in Winnipeg and from a regional sub-office in Brandon. From the middle of May until the end of August of each year, provincially appointed inspectors and officers search for elm firewood and diseased and dead elm trees in each of the managed communities.

Inspectors marking elm firewood
Inspectors marking elm firewood

Starting in mid-June, when infected trees usually start showing symptoms DED symptoms, inspectors begin to survey for trees that are nearly dead or are infected with DED. Dead and infected elm trees are highly attractive to bark beetles as brood material and may produce large numbers of elm bark beetles.

These surveys require that inspectors, who usually work in pairs, visually inspect every property in the community. This means that crews will drive slowly (10 km/hr) down each street and back lane looking for wood or trees. Properties that cannot be easily seen from roads or back lanes will be surveyed by foot (i.e. riverbank properties). The crews have binoculars and may use them to look at the crowns of trees for DED symptoms, or they may use them to look at firewood piles. Inspectors wear high visibility vests that say "Manitoba Forestry" on the back. The vehicles have signs that say "Manitoba Conservation" or "Sustainable Development".

Inspectors preparing for a survey
Inspectors preparing for a survey

Under The Forest Health Protection Act, inspectors and officers may enter upon private property for the purpose of inspection without permission from the property owner. The inspectors will attempt to talk to the property owner first by knocking on the door, but if no one answers, the crew will proceed with an inspection of the property. If someone is available, the crew will explain the program and their reason for inspection. The inspectors will have identification with them that shows that they are inspectors under the Act.

In the process of determining if a tree has DED, inspectors may have to take a sample from the tree using pole pruners to look for a characteristic stain under the bark.

Taking a sample of a tree with DED
Taking a sample

tree with orange marking paint
Marked trees

If elm wood or DED infected trees are found on the property, the inspectors will make a record of the detection, mark the material with orange tree marking paint, fasten a metal tag to the material, and leave a letter at the property.

Removals

Elm wood

Elm firewood can contribute to the spread of DED and it is illegal to store or transport in Manitoba. If elm wood has been marked on a property, the owner must destroy (burn, chip) the wood or take it to a designated elm wood disposal site (usually the local landfill) within the two weeks outlined in the letter left by the inspectors.

On occasion, an Elm Wood Storage Permit can be obtained by contacting the Tree Line (see contact information at the bottom of the page). Such permits are rarely issued, and each request is considered on a case by case basis.

Elm Trees

Removal of marked trees takes place throughout the year. The trees should be cut close to the ground, but the stumps will not be removed. To learn more about removals in your community please contact your local municipal or public works office.

If a property owner would like to remove the tree themselves, or if they want to have the tree taken down by someone else, they can do so, but the regulations regarding the treatment and disposal of this material must still be followed. Associated costs will not be reimbursed.

You Can Help

Urban elms in DED managed communities continue to thrive 40 years after DED was first detected in this province. Much of the success of the Dutch Elm Disease Management Program in Manitoba is a result of public participation and cooperation. To report elm wood or a potentially infested tree, or for more information on the program, please contact:

Provincial Tree Line: 204-945-7866

Forestry and Peatlands Management Branch Office (Brandon): 204-726-6444

To learn more about Dutch elm disease, please visit:
https://www.gov.mb.ca/conservation/forestry/ded-urban/faq.html
https://www.gov.mb.ca/conservation/forestry/pdf/health/dutch_elm_general.pdf
https://www.gov.mb.ca/conservation/forestry/pdf/health/dangers_storing_elm.pdf