Most deicing products readily available contain salt compounds known as magnesium chloride (used as a liquid on roads), sodium chloride (table salt), calcium chloride, and potassium chloride (fertilizer). Each winter these materials are applied to sidewalks, driveways, and steps to prevent slipping and falling. However, they are often applied without regard to the substance, application, or the damage that they may cause to the home, property, environment, pets, and nearby plants.
As for mentioned, deicing products are primarily comprised of salt. And just like household salt, all salts are not the same. Salts can cause injury to trees, lawns, and shrubs, corrode metal and concrete, and even do bodily harm to pets and humans. The most problematic element in any of the deicing products is the chloride; it causes corrosion and is toxic to plants.
Most of the popular de-icing products sold are chloride-based, each containing a different combination of salt. They include:
- calcium chloride,
- sodium chloride,
- potassium chloride,
- magnesium chloride.
Of these, the most commonly used is sodium chloride; it is widely available and least costly. It works at lower temperatures than other products and does not harm plants if excessive amounts are not applied.
This table from Purdue Extension gives valuable information about deicers:
While Calcium magnesium acetate (CMA) is listed on the above table, it contains no chloride and is less damaging to cars, metals, and concrete and less toxic to plants. It is made from dolomitic limestone and acetic acid, the main compound found in vinegar. CMA works differently than other deicers; it does not form brine like salts, but rather helps prevent snow particles from sticking to each other. It has little effect on plant growth or concrete. It is also said to be biodegradable and pet and wildlife friendly. The big downside is the cost.
If you want to avoid deicing products, consider using sand, kitty litter, or chicken grit. While these products won’t melt snow, they will provide traction in slippery spots. Sand and kitty litter are safe for pets and plants and can be swept up when the snow melts. (Chicken grit may be too sharp for the paws of some pets but will not harm plants.) Boots or shoes traversing any of these products should be removed upon entering a home as they could scratch floors.
Should the landscape fall victim to deicing, flushing the area around the plant roots in the spring with water will help to leech out the salts. Flushing may not be helpful if excessive salt has been used and plants and grass are found dead in the spring along deiced areas. Consider planting salt-tolerant plants in the landscape where deicer products may be used. For a list of landscape plants describing their tolerance to salt, visit Salt Damage in Landscape Plants by Purdue Extension.
The best advice is to know something about the substance (salts used in the product), consider the application, and then READ AND FOLLOW the manufacturer’s directions for applying the product to minimize damage to property and landscape. And if possible, apply even less than is recommended. Deicing products are not meant to replace shoveling or to melt all snow and ice, but to aid in removal efforts to prevent slipping and falling.
Sources:
Picking the Right Product is Key to Melting Ice From Sidewalks, Driveways, K-State Research and Extension News
Salt Damage in Landscape Plants, Purdue Extension
Ice Melts Can Help But Can Be Harmful, K-State Research and Extension
Using Deicing Salts in the Home Landscape, Iowa State University Extension and Outreach
Reviewed and updated 6/2024, mg.
