Garden Clippings for March 2, 2019
Driving home from Toronto a few days ago I came across three salt trucks spreading tons of sodium chloride over the roads. And while I was grateful for the safety that the salt provided me and my fellow drivers, I was not thrilled with the thought of the resulting negative environmental impact.
Road salt does not evaporate or miraculously disappear. As soon as it hits the ground it has the potential to harm both animal and plant life. Many plants and trees are not salt tolerant. Road salt also lands up in ditches and streams where it negatively affects aquatic life.
The Department of Highways and Ministry of Transportation are becoming wise to environmental issues and are now using salt more sparingly while researchers are busy looking for alternatives.
What should homeowners to do minimise the potential damage of salt? Are there products available that will melt ice while not damaging concrete or vegetation or the paws of your pets?
There is a myriad of products on the market that claim to be pet friendly, environmentally safe and will not damage concrete. All the claims of these branded products should be taken with a grain of salt. (pardon the pun). Most are blends of a variety of ingredients and many contain at least some salt or salt related product.
Sodium Chloride or rock salt is inexpensive and very effective. It will work as long as temperatures don’t go much below -10 degrees Celsius. But sodium chloride is corrosive and is more harmful to plants and animals than the alternatives.
Calcium Chloride, like sodium chloride, serves to lower the freezing point of water. It is highly effective and will melt snow and ice in extremely low temperatures. Calcium chloride is less harmful to plant life and less corrosive to metal and concrete. But it is more expensive.
Magnesium chloride claims to be safer for plant, animal and aquatic life and less corrosive than the common alternatives. Its drawbacks are higher cost and less effectiveness. Magnesium Chloride will not work well if temperatures reach much below -15 degrees C.
Potassium Chloride’s impact is similar to Magnesium chloride, but won’t be effective if temperatures dip below -10 degrees C.
Calcium Magnesium Acetate (CMA) is widely considered to be one of the most environmentally friendly products, and will work as long as temperatures don’t go below -7 degrees C.
Urea is a bio-degradable product that is a common ingredient in grass and plant fertilizers. When used sparingly it will not damage plant life, concrete or pavers. Propylene glycol is a relatively new de-icer and is considered safe for pets and humans.
Regardless which product you choose, be sure to apply it sparingly. If the de-icer has done its duty and there are leftover grains on the concrete, sweep it up and put it back in the container for future use. Finally, consider adding sand or kitty litter to the mix to provide traction.