Sleet, snow and freezing rain are unescapable parts of winter, and the accompanying slippery sidewalks and treacherous winter driving conditions are annoying and dangerous. That’s where ice removal comes in.
Sidewalk salt — also known as road salt, ice salt and rock salt — is a common, affordable and effective de-icing compound used by cities and homeowners across the country. But it does have some downsides. Sidewalk salt that gets into your lawn and garden can damage to a slew of things around your home. You may be willing to accept the potential side effects, or decide to try greener road salt alternatives. Here’s what you need to know.
What Is Sidewalk Salt?
Sidewalk salt melts ice on roads and walkways to prevent accidents and falls. Sodium chloride is the most commonly used de-icer around the U.S., according to the Minnesota Pollution Control Agency (MPCA). But it is not the only option.
Many types of de-icing compounds, including chlorides and non-chlorides, get lumped under the sidewalk salt umbrella. Lowe’s snow melt buying guide identifies four common ice melt active ingredients: sodium chloride, calcium chloride, magnesium chloride and calcium magnesium acetate.
While each has a different chemical makeup, they all melt ice by lowering the freezing point of water below 32 degrees F. Ice will still form if temperatures drop far enough.
Lowest melting temperature of 15 F;
Negatively impacts plants;
Least expensive option.
Lowest melting temperature of -20 F;
Negatively impacts plants;
Harmful to skin, may cause ulceration to your dog’s mouth if ingested.
Lowest melting temperature of -10 F;
Negatively impacts plants;
Most harmful to concrete.
Calcium Magnesium Acetate:
Lowest melting temperature of 20 F;
Has the least effect on plants;
Most expensive option.
How Sidewalk Salt Affects Lawns and Gardens
Small amounts of road salt are unlikely to damage your grass and landscaping. However, heavy use can lead to brown and stunted greenery, particularly if you use products containing sodium chloride.
Shelby DeVore, a gardening expert and founder of Farminence, explains that when “salts settle around the roots of the plant, they can create an environment that prevents the plant from absorbing water.” Salt can even pull water out of plant roots. This may lead to brown grass.
Excess salt in your soil also affects a plant’s ability to absorb nutrients. Instead of getting things like potassium and phosphorus, the plant will soak up salt, which DeVore says can lead to chloride toxicity.
Since plants can’t sweat out salt, DeVore says those “that have excess sodium will push it into the leaves. The leaves will then die and fall off, thus removing the excess from the plant.” DeVore says deciduous plants are less susceptible to damage over time than evergreens because they shed their leaves every year.
Greens planted near roads and driveways are exposed to more salt. If you live in an area where ice salt is prevalent, DeVore recommends placing sensitive plants away from your hardscaping. Watering your lawn may flush out excess salt from your soil. You can also amend your soil with lime or gypsum, according to the USDA Natural Resources Conservation Service.
Sidewalk Salt’s Effect on the Home
De-icing salt is well known to cause rust on vehicles. Washing your car often in the winter helps, but limiting your use of salt is key. Salt can also stain your floor mats, so be sure to clean them while cleaning your exterior.
Another major concern is sidewalk salt’s effect on concrete driveways, patios and sidewalks. Although de-icing products are unlikely to visibly damage concrete itself, melting and refreezing exacerbates existing problems.
“The ice that melts needs to go somewhere, and sometimes that means between the cracks in your driveway,” says Leann Greto, head of product development and merchandising at Garrett Wade. “Salt doesn’t interact with the cement that bonds the aggregate together, but the ice acts as a wedge that can structurally weaken your driveway.”
Ice melts can cause damage below ground, too. Greto points out that “salts are by nature very abrasive,” so they can weaken your pipes and even cause leaks.
Is Sidewalk Salt Green?
In short, sidewalk salt is not the greenest option. But it is undeniably effective. The MPCA says that 30 percent of the chloride salt used on Twin Cities roads ends up in the Mississippi River. Besides runoff, the salt that sinks into topsoil can leach into groundwater. And its impact on vegetation allows more erosion.
Road salt has surprising effects on wildlife, from butterflies to deer. Milkweed growing along heavily salted roads in Minnesota weakens butterflies, while the same plant with less salt proves beneficial. Ed Spicer, CEO of Pest Strategies, says that road salt draws “deer looking for a salty snack onto busy roads, thereby causing increases in accidents.”
Minimizing Damage and Road Salt Alternatives
If the cracks in your driveway worsen every spring and the nearby plants struggle, salt may be the culprit. There are lots of road salt alternatives to consider.
DeVore recommends de-icing compounds without chloride. The Environmental Protection Agency provides a list of environmentally friendly ice melt products. You can even make DIY ice melts.
If all you need is a little extra traction, there are simple solutions. Start by trying sand. It won’t make snow or ice melt faster, but it will give your tires and shoes more grip.
When you do need to use sidewalk salt, refrain from piling salty snow onto your lawn when you shovel. And don’t spread too much. How do you know if you’re using too much salt? One clue is leftover pieces on clean, dry surfaces. If salt still litters your driveway after the snow melts, try using less. It will save money while minimizing the damage around your home.