“With the annual ban about to be lifted, it’s time to start taking the dead wood out of your elm trees,” says Janet Feddes-Calpas, executive director, Society to Prevent Dutch Elm Disease (STOPDED). “To help eliminate elm bark beetle habitat, elm sanitation is essential to an integrated Dutch elm disease (DED) prevention program to keep Alberta DED free.”
The only time it is legal to prune elms in Alberta is between October 1 and March 31. “This is when the elm bark beetles, responsible for spreading the deadly DED fungus, are not active,” says Feddes-Calpas. “Elm bark beetles feed on healthy elms and breed and overwinter in dead and dying elm trees. If elm trees are pruned between April 1 and September 30, beetles will be drawn to the scent of the fresh pruning cuts, potentially infecting an otherwise healthy elm.”
Having your tree pruned properly is important, says Feddes-Calpas. “STOPDED recommends that all trees be pruned by a professional arborist such as an International Society of Arboriculture (ISA) Certified Arborist. They will determine what type of pruning is necessary to maintain or improve the health, appearance and safety of your trees. Improper pruning, topping or removing an excessive amount of live wood is not recommended, as this type of pruning will weaken the tree’s structure and shorten its lifespan. It is essential that all pruned elm wood be properly disposed of by burning, burying or chipping by March 31. And, it’s illegal to store elm firewood since it could be harbouring elm bark beetles.”
While Alberta is still free of DED, its borders are being pressed from two sides, Saskatchewan and Montana, both of which are battling the disease. “Once an elm is infected with DED there is no cure and it must be removed and destroyed immediately,” says Feddes-Calpas. “We must stay vigilant to keep our elms healthy. DED can be prevented.”
For more information, call the STOPDED hotline at 1-877-837-ELMS or see Society to Prevent Dutch Elm Disease. To find an ISA Certified Arborist, see International Society of Arboriculture Prairie Chapter.
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