Snow-melting and de-icing products like rock salt are harmful to trees, plants. Here’s why — and one alternative.

Sodium chloride — rock salt — is the cheapest and most common ice-melting chemical. Other chemical cousins, such as calcium chloride, magnesium chloride, and potassium chloride, are also used. Potassium chloride is somewhat less damaging to plants, but “it’s not benign,” Janoski said.