Between April 1 and September 30, it is illegal to prune elm trees and store elm firewood in the province of Alberta. All pruned elm wood should have been burned, chopped or chipped between Oct. 1 and Mar. 31.
Although Alberta remains DED free, in 1998 the Elm bark beetle, which carries the fungal disease and is responsible for spreading it by feeding on healthy elms and breeding in dead and dying ones, was found in Wainwright. The tree was removed and burned as soon as the disease was detected. Throughout the 1990’s, a smaller European elm bark beetle, which can be a carrier of the disease, was found in Calgary, Red Deer, Wetaskiwin, St. Albert, and Edmonton. Since Edmonton has one of the largest concentrations of uninfected American elms in the World with a price tag of $634 million, the province wide ban serves as a preventative strategy to keep them protected.
The beetles are known to be active from April to September, so if elm trees are pruned during this duration of the ban, it is possible that the beetle will be attracted to the sent of the fresh wound therefore possibly infecting other healthy trees. When a tree is infected with DED, it can die as soon as one year later.
Each year many trees die simply as a result of improper pruning. It is recommended that pruning be carried our by a professional certified arborist. He or she can properly recommend the amount and type of pruning needed for individual trees.
For more information on DED and preventative measures, visit Society to Prevent Dutch Elm Disease (STOPDED) website at www.stopded.org or www.alberta.ca