Before you pour salt on your driveways to melt snow and ice, consider the impact it has on your plants, pets, pavement, and water quality. Explore seven less harmful ways to melt ice—as well as ways to use less salt!
Rock salt (sodium chloride) has been the conventional choice to melt ice on driveways and sidewalks as salt has a lower freezing point than water. Rock salt is effective to approximately 12°F, but can damage soils, kill plants and grass, and cause driveway and car problems. It’s also toxic to animals when ingested. Plus, if you care about keeping local waters pristine, salt causes problems with over-salinization of rivers and lakes.
Negative Impact of Salt
If your front walk or driveway is made of porous paving materials like concrete or brick, salt causes freeze and thaw cycles that eat away at it and makes it prone to cracking and crumbling.
Salt can dry out and burn your pets’ sensitive paws, causing painful cracks and open sores. Licking the salt off also puts them at risk for gastrointestinal problems. If they ingest enough salt, it can be lethal!
Salt runoff can contaminate well water and reservoirs and wash into lakes and streams where it is toxic to fish and amphibians.
Salt injures plants in many ways often causing a slow death. Roots take up salt which accumulates in plant tissues causing nutrient imbalances. Salts also make it difficult for some roots to absorb water which leads to dryness and drought stress.
Large amounts of sodium can chemically change the clay in the soil, decreasing drainage.
Salt spray, splashed up from the roads, can cause chemical toxicity to the plants, especially evergreens within the splash zone.
Salty deposits on the surface of twigs, leaves, and buds dehydrate them and interfere with photosynthesis, transpiration, and respiration.
Signs of Salt Damage to Plants
The University of Wisconsin lists these signs of salt damage to be on the lookout for:
Browning leaf edges
Wilting during hot dry weather
Fewer or smaller leaves
Yellow leaves that are a sign of chlorosis
Premature fall color and early leaf drop
Smaller than normal flowers and fruit
Evergreens with discolored needles
7 Alternatives to Rock Salt
There’s no “perfect” ice-melt solution but here are some solutions that are less damaging than 100% rock salt.
Rubbing Alcohol: In a bucket, mix 1/2 gallon of warm water with 6 drops of dish soap and 1/4 cup of rubbing alcohol ($1.99 for 16 ounces where I live which would make MANY batches). Splash this around on your icy spots and watch the ice bubble up and melt away. It’s very effective and satisfying! The rubbing alcohol has a much lower freezing point than water so it thaws ice and prevents re-icing! (Rubbing alcohol often appears as one of many ingredients in commercial ice melts.)
You can also combine the alcohol with water in a spray bottle, creating a portable ice-melting solution to keep in your car to defrost your windshield! Often, airplanes use rubbing alcohol to defrost the wings of a plane.
Epsom Salt: Epson salt isn’t as harmful to plants or vegetation as rock salt (or table salt). You may already have some on hand from the garden. It is an abrasive and melts ice slowly. To speed up your Epsom salts’ melting power, combine sugar and Epsom salt in a 1:1 ratio. As Epson salt costs more than rock salt (6 pounds for $5.29 where I live), perhaps save it for the front steps when company is coming.
Garden Fertilizer/Alternative Salts: Check your garage to see if you have any fertilizer left over from gardening and check the label for below ingredients. These salts are slightly gentler than rock salt though they are more expensive and they still have some of the disadvantages of salts described above.
—Calcium chloride is the popular ingredient in commercial de-icers and melts ice to about -25 degrees F, lower than rock salt. It will form slippery surfaces on its own, so mix it with sand—one part to 3 parts— to stretch it and add abrasive qualities. It’s very quick-acting and melts ice almost instantly. It’s less damaging to concrete than other ice melts. However, overapplication can still harm plants as well as corrode metals, damaging your car. Plus, it’s strength makes it the least pet-friendly of the salts and very irritating to pets’ paws.
—Magnesium chloride is effective down to 0 degrees and also a popular ingredient in de-icers. The advantage is that it offers a more environmentally-friendly alternative to calcium chloride. It causes minimal damage to surfaces, it’s less harmful to plants, and it’s less irritating to pets’ paws than rock salt or calcium chloride. However, keep it mind it’s still a salt so it still has the issues of salt residue and crumbling driveways as all salts, just less severe.
Urea: While also an ingredient in fertilizer, Urea (carbonyl diamide) is not salt-based. It’s environmentally safe and doesn’t cause damage to concrete. It’s often used on airport runways. It can melt ice down to temperatures of 15℉. In the spring, you might notice that the edges of your lawn grow more vigorously! The ASPCA Animal Poison Control Center recommends an urea-based product as it’s gentlest on pets paws and least likely to cause poisoning. Urea is different because it doesn’t pull water from paws as much as salts do. If eaten, urea is nontoxic to dogs (though it may cause vomiting).
Calcium magnesium acetate (CMA): A new, salt-free melting agent, CMA works differently than other materials in that it does not form a brine-like salt. Instead, it helps prevent snow particles from sticking to each other or the road surface. CMA is made from dolomitic limestone and acetic acid (the main compound of vinegar). This material has little impact on plants and animals and is a good alternative for environmentally-sensitive areas. It’s considered biodegradable and don’t damage brick or concrete surfaces. That said, it is a more expensive alternative.
Natural Fertilizer: Alfalfa meal, wood ashes, coffee grounds. Alfalfa meal is a great non-chemical fertilizer that won’t burn your plants. Wood ash from your fireplace contains potassium salts that help melt ice. Ash also absorbs solar energy, increasing the temperature to melt the ice. All these abrasives will help speed melting AND improve traction. Plus, they have relatively few impacts on the environment or plants.
Salt Plus Hot Water: Here’s a way to use rock salt but also lessen the harm that it does while increasing its effectiveness! To melt ice more quickly, salt shouldn’t sit on top of the ice; it needs to permeate the ice When that water re-freezes, the corrosive effect of salt damages the concrete. The trick is to use hot water to melt the ice and then a small amount of salt to prevent the liquid water from re-freezing.
For your doorsteps or a stubborn area, just boil a large pot of hot water and gently poor on ice. The trick is to sweep the water off the surface so that it doesn’t get cold and freeze. Then sprinkle the salts. Using hot water is not less harmful and more effective but also means that you will end up using less salt.
8 Ways to Use Less Salt
Clear the snow first! The more snow and ice present, the more de-icing compound is needed for melting. Use minimal de-icing product to treat the pavement.
If you’re going to use salt, don’t scatter it around willy-nilly. Put it in the spots where you need it, not over the entire driveway. For example, sprinkle it near the door and along the entryway to your house after you shovel off everything you can.
Get a shovel with a sharp aluminum edge strip on the end of the shovel scoop. This metal strip is more effective at removing ice from your driveway!
When landscaping, avoiding planting right along the driveway. Plant any salt-susceptible plants away from roads and sidewalks.
In the spring, irrigate the areas that had snow/salt buildup to lessen effects to the root zone of plants. Especially pay attention to any landscape beds that become heavily contaminated (from salty snow being dumped on them) and flush with fresh water as soon as possible.
Salt-covered foliage should be hosed off with clean water as soon as possible.
Use barriers, gutters, and hardscaping to channel de-icing materials away from the garden and plants.
If vegetation is located in areas where heavy salt spray occurs, erect barriers or screens to protect plants (especially evergreens) during the winter months.
Abrasives to Stop Slipping
If you are running out the door or have guests coming and you can’t wait for ice to melt, toss kitty litter or sand or sawdust by hand over the ice! Make sure it’s plain non-clumping clay kitty litter (save the clumping perfumed stuff for inside the house). In general, it’s always a good idea to combine a de-icer with an abrasive to keep folks from slipping.
Learn anything new today? Whatever de-icer and abrasive you choose to use, keep the safety of people, pets, property and the planet in mind!