Recent snow and ice storms have prompted questions about impacts of road salt to landscape plants, aquatic vegetation, water, human health, pets, wildlife, and soil. Most salt used on roadways is sodium chloride, with a small amount of anti-caking product added. Salt enters the environment through runoff from melting snow, rain, splash from vehicles, wind, and pedestrian traffic. Sodium and chloride have an impact on turf, groundcovers, shrubs, and trees, as well as aquatic plants. Salt can disrupt nutrient uptake, but most plants are dormant in the winter. The larger effects are due to dehydration which leads to foliage damage, and can affect stems, flowers, and seed germination. Plants that have formed buds in the fall are susceptible to salt damage to those buds. Evergreens may show bleached brown or bronzed foliage or tip browning.
Salts can change soil chemistry, and affect soil microbes. Roadside plant buffers help to protect landscapes and waterways. Salt tolerant plants are good choices for areas prone to salt runoff and spray. A fact sheet from UD Cooperative Extension (http://extension.udel.edu/factsheets/delaware-gardening-challenge-to-newcomers/) lists salt tolerant plants such as bayberry, groundsel, summersweet, and beach plum, for coastal Delaware where storms bring salt spray and wind. A publication from Delaware Nature Society lists native plants and their environmental tolerances: http://www.delawarenaturesociety.org/DNS_Docs/Conservation/Native_TreesShrubs.pdf. Tree species with salt tolerance include oak, locust, hickory, birch, buckeye, and ginkgo. Spring rains usually help to dilute salt levels naturally in soils. Calcium magnesium acetate, sand, and cat litter are alternatives for icy home sidewalks.
NFG 1/23/2018
