Too much salt in a person’s diet can cause problems. Here in our northern climate the same can be true for plants located near sidewalks and roadways.
No plant is totally immune to salt damage, but some will tolerate it better than others. Salts can affect plant growth by drying them out, altering the soil structure around the plant, and altering the mineral nutrition in the plant. Some signs of salt damage are death of buds and twig tips, evergreens may become yellowed or brown in late winter to early spring, and plants may show stunting, poor vigor and early leaf drop during the growing season.
You can minimize damage with plant selection, placement and care. When landscaping, use plants that are not in the colder portion of their hardiness range. While they all set out to do the same job, some of the deicing materials on the market today are friendlier to our grass, plants and soil than others.
Read the package label when shopping for a deicing agent. Rock salt or sodium chloride is easy on the wallet and will work well at low temperatures but it is also very corrosive on metals like your snow shovel and it is not a good thing for plants and soil. Magnesium chloride is one of the safest deicers to use in the landscape and works well in low temperatures but can be a bit more costly than the sodium chloride. Calcium chloride and potassium chloride can be used also but are not considered to be as safe as the magnesium product.
To minimize damage, you could consider using less salt. Mixing 50 pounds of sand with 1 pound of deicing agent will be gentler on your landscape and will give you more traction on slippery surfaces. Liquid solutions are also available or you can make your own by dissolving a small amount of deicing agent in hot water. Try two parts water to one part magnesium chloride and use a plastic hand pump sprayer to apply.
Salt spray from roads can cause problems with evergreens and shrubs. One alternative would be to erect a burlap screen or snow fence between the plants and the road and leave it up all winter.
When salt laden, piled up snow melts, the salt will accumulate in the soil and can damage plants. The best way to move that accumulation out of the plant root zone is to apply a large amount of water to the area in an attempt to leach it well.
As always, Happy Gardening!