Winter weather can be tough on communities, especially when it comes to keeping streets, highways, and sidewalks safe from snow and ice. Deicing salt is a go-to solution, but it comes at a cost: harm to trees and other plants in the landscape.
How Road Salt Affects Trees
Road salt, typically sodium chloride, can harm trees in two key ways:
- Airborne Spray Damage
During winter storms, salt spray can land on dormant buds, penetrating through leaf scars and killing them before spring growth begins. - Soil Contamination
When salt accumulates in the soil, it breaks down into sodium and chlorine, both of which disrupt the natural balance of nutrients and water uptake in trees.
Key Salt-Induced Issues for Trees
- Water Loss
Salt in the soil creates a more concentrated solution around the roots, preventing the tree from absorbing water through osmosis. This can lead to dehydration and stress. - Chloride Poisoning
Chlorine ions absorbed by roots in early spring can travel through the sap, concentrating in shoots and leaf margins. This often results in leaf scorch, curling, and death. - Nutrient Deficiencies
Sodium competes with essential nutrients like magnesium and potassium, which are critical for chlorophyll production. Severe imbalances can weaken the tree’s resistance to drought, disease, and pests.
Over time, salt-weakened trees are more vulnerable to environmental stresses, such as wind and ice, as well as insects and pathogens. While direct death from salt exposure is rare, these secondary stressors can significantly shorten a tree’s lifespan.
Steps You Can Take To Protect Trees From Salt Damage
While avoiding deicing salt entirely isn’t practical, you can reduce its impact on trees and plants by adopting some best practices:
- Choose the Right Deicer
opt for products with calcium chloride or calcium magnesium acetate instead of sodium chloride. These alternatives are less harmful to trees. - Reduce Salt Usage
- Shovel, scrape, and sweep snow frequently to minimize ice buildup.
- Only apply deicers to critical areas and use them sparingly.
- Apply Deicers Correctly
- Always read and follow the product instructions, including recommended temperatures for application.
- Remove snow before applying deicers—do not spread salt directly onto snow.
- Avoid piling snow on or near shrubs or trees, as it may contain salt and damage the plants.
- Flush Salt in Spring
When the ground thaws, heavily water areas where salt may have accumulated to flush it out of the root zone. A thorough soaking can help mitigate salt damage.
A Balanced Approach
By choosing safer deicing materials, practicing proper application, and caring for your trees year-round, you can help maintain a healthy urban landscape while ensuring winter safety. Balancing these priorities isn’t always easy, but your efforts will pay off with stronger, more resilient trees and a safer environment for everyone.
