Road salt, or de-icing salt, is used extensively every winter in Canada. Snow is shoveled and pushed away from roads, parking lots, driveways, and sidewalks, and salt is applied to the surfaces to prevent ice and ensure winter safety for road users. Sometimes, snow debris containing salt is plowed under the base of trees when there is no suitable storage area.

As temperatures warm, the snow melts, releasing a high concentration of dissolved road salt. This solution can affect all types of trees and plants by altering the soil properties.

Symptoms and Damages

• Deciduous tree: repeated twig dieback, buds fail to start in spring time
• Evergreen tree: browning needles begin from the top and progress to the tree base
• The side of the tree closest to the road show more damage.
• Salt can also accumulate in the cambium and eventually kill the tree.
• Reduced tree vigor and stressed tree are more susceptible to other pests and diseases.
• Increased soil pH level can affect overall tree health.

What to do?

• Minimize salt deposition near your tree.
• Protect young tree from road splash or mist using burlap or temporary fencing in winter
• Implement soil amendments to improve soil properties of damaged trees.
• Plant salt tolerant trees/shrubs such as sea buckthorn, rocky mountain juniper, hawthorn, mountain ash, and green ash.