All elms are susceptible to Dutch Elm Disease. To protect our elms there is an elm pruning ban from April 1 to August 31 each year, during which time it is illegal to prune elm trees. It is also illegal to store or transport elm wood; if you have elm wood contact Parks and Recreation for your free elm wood disposal permit, which allows you to take your elm wood to the City landfill free of charge.
Elms can still be a useful urban tree. Plant a mix of species to prevent the spread of diseases – two plants of the same species can easily infect each other if growing close together. If you would like to plant an elm, look for a DED resistant variety such as Prairie Expedition, Discovery Japanese or Triumph.
American Elm (Ulmus americana): Fast growing, native North American shade tree. Beautiful vase shaped form makes this a perfect boulevard tree. Dark green leaves turn yellow in fall. Tolerates both wet and dry conditions. Variable response to DED as each tree is slightly different. Height: 20 m; Width: 15 m. Prefers full sun. Zone 2.
Brandon Elm (Ulmus americana ‘Brandon’): Fast growing, cultivar of the American Elm with a more compact, vase-shaped canopy. Dark green leaves turn a nice gold colour in fall. Tolerates both dry and wet conditions, but susceptible to DED. Height: 15 m; Width: 8 m. Prefers full sun. Zone 2.
Siberian Elm (Ulmus pumila): Not recommended for planting in urban environments due to slim flux and cankerworm susceptibility and a tendency to become weedy. Very similar to American Elm but with smaller leaves, round buds and prolific seed production. Shows some DED resistance and is useful as a farm shelterbelt species. Height: 15 m; Width: 12 m. Prefers full sun or partial shade. Zone 3.