Photo credit: Lois Miklas
Waking up to a beautiful but icy wonderland can be a reminder to purchase a bag of “salt” in preparation for the next winter storm. However, it may not actually be salt in the bag of de-icer, but one of many substances used to melt ice.
Icy surfaces can be hazardous to wintertime health, so removing snow and ice is a priority. Although safety comes first, gardeners also want to consider run-off damage to lawns and gardens. This can be a challenge for plants near roadways, sidewalks, and other hardscape areas. Gardeners may want to consider selecting salt-tolerant plants for areas near heavily salted roads.
Chemical de-icers come in various forms—pellets, flakes, and liquids—research shows that pellets from 1/16 inch to 3/16 inch in size work the fastest. Regardless of the type, overuse causes problems. Use only as much as necessary.
Sodium chloride, also known as rock salt, melts ice in temperatures down to 25°F. It is inexpensive, but can burn plants as well as corrode metal and concrete. It can seriously injure or kill plants growing near sidewalks or paved areas. Additionally, when it washes into storm drains, it is a nonpoint source of pollution to waterways impacting fish and marine life.
Other chemical choices include calcium chloride which melts ice in temperatures down to -25°F. Overuse can also harm plants.
Potassium chloride, a fertilizer, is effective to about 12°F; however, overuse can again be deadly to plants.
Magnesium chloride melts snow and ice down to -13°F. It releases 40% less chloride than either rock salt or calcium chloride and is less damaging to vegetation.
Calcium magnesium acetate (CMA), is a formulation of dolomitic limestone and acetic acid. It is effective down to 5°F and is particularly useful in environmentally-sensitive areas. CMA is also applied in a liquid form to roads and bridges before a storm to prevent snow and ice from bonding to the road surface.
For areas where de-icers cannot be used, sand or kitty litter can provide traction but also can be a source of nonpoint pollution. Remember to consider your landscape and possible effects of pollution when selecting a product to treat icy surfaces.