Steps you can take to help prevent salt damage and keep your trees happy

1. Use less salt.
   

2. Try less toxic deicers like calcium magnesium acetate (CMA).
   

3. If the soil drains well, repeated drenching in the spring will help wash the salt out.
   

4. In areas where salt is unavoidable, plant only salt- tolerant species.

Preventing the degradation of trees from salt

Salt damages plants in two ways - via an airborne spray that kills dormant buds by penetrating leaf scars, and in the soil where it breaks down into its two components - sodium and chlorine – which act differently to kill the plant. Salt damage may not become evident until late into the summer, when it often causes brown, scorched- looking leaf margins. Salt damage is cumulative- each year’s injury causes further stress to a tree, until eventually symptoms become evident and physical decline begins.

Direct contact salt sprayed onto trees by snowplows, traffic and snow blowers sticks to buds, twigs and foliage (in the case of evergreens). This direct contact can burn tissues, cause disfigured or yellowed foliage, and kill affected limbs. Severe or repeated exposure, especially for sensitive species like white pine, can cause death of the whole tree.

In high enough concentrations, salt will kill a root system. At lower concentrations salt makes water unavailable to tree roots, producing drought stress even in moist soil. Salt also damages the soil structure, causing "sodium compaction". Roots need to get oxygen from soil pores, and healthy soil forms tiny natural clumps which allow pore space. Salt breaks the chemical bonds holding the clumps together and the pore spaces close.