American Elm

American Elm is a large, fast-growing deciduous tree native to Ontario. Once a widespread and common tree, they are found much less frequently due to the invasive Dutch Elm disease. However, it still has extraordinary value for wildlife. It's the larval host for Eastern Comma, Mourning Cloak, Painted Lady and Question Mark butterflies, as well as the Columbia Silkmoth. The large branches provide shelter and nesting sites for various birds and small mammals, and the seeds are food for birds and small mammals. 

American Elm grows best in full to part sun with moist, average, well-drained soil. However, it is highly adaptable, tolerating temporary flooding, road salt, pollution and clay soil. 

Dutch Elm disease is still a problem, but there are ways to help prevent infection. Avoid pruning during the times the beetles that spread the disease are active (usually April 1st-September 30th), remove dead, damaged, and/or diseased branches promptly, and keep your tree healthy by ensuring a good watering regimen when young and adequate nutrients in the soil.