How can I best keep my sidewalks safe during the winter? The snow so far this year has been a big challenge.
— Erin Holbach, Gurnee
Winter has gotten off to a fast start this year, with lots of snow along with some cold weather. There is a lot of winter weather yet to come, so it’s best to be prepared. One of the most important steps in effective snow management is proper removal. You may want to consider purchasing a snow thrower or snow blower if you have a large area to clear. A snow thrower is a single-stage machine that gathers snow with an auger and discharges it through the chute in a single motion. They’re good for storms with 8 to 9 inches of snow or less. I’ve even used a snow thrower with a rubber paddle for much deeper snow at home, and I have a big driveway, but it was time-consuming to work through the drifts. My driveway was built with old Chicago brick and has a slightly uneven surface, but the rubber paddles on my snow thrower handled it with ease. A snow blower will be available in bigger sizes to remove snow more quickly and will have more power to handle deep snow. The snow is removed in two stages, with an auger feeding the snow into an impeller, which sends the snow through the chute. These machines will typically be self-propelled. The best choice for you depends on the size of the area that you have to clear, and your budget. Snow throwers require more effort to operate, but I found it easy to clear the first 8-inch snowstorm with my small paddle snow thrower.
I consistently see ice melt products over-applied by homeowners and commercial businesses, which is harmful to the hardscape and to the environment. Removing snow before it’s packed down from walking or driving can help; snow covering your walks and driveway can turn into ice with consistent traffic. This happened on the walk out of my back door after three to four days of foot traffic from letting dogs out in the past. I’ve been very careful to keep this walk clear this winter, since an icy walk is always dangerous, and more so when it’s dark. You shouldn’t need to apply deicing products after every storm, and when you do, you shouldn’t need it on all the driveway and sidewalk surfaces. Read the label of the product you’re planning to purchase and follow the label instructions to maximize effectiveness and minimize negative effects. Calcium chloride, which works when temperatures are as low as minus 20 degrees Fahrenheit, is less damaging to plants than products made with sodium chloride (rock salt), but it’s similarly harmful to carpet, tile, and shoes and it’s corrosive to concrete and metal. A similar product, potassium chloride, is also less damaging to plants and works until temperatures drop below 15 degrees. Calcium magnesium acetate (CMA) is generally considered to be the best deicer with less impact on plants and the environment. It’s effective for temperatures as low as 20 degrees, so it loses effectiveness in cold weather. Many ice melt products on the market include a blend of active ingredients to maximize performance at different temperatures. The key thing is to apply only the recommended amounts to minimize negative impacts on garden plants and hardscape, and only when needed. I only use ice melt at home when I feel conditions would be very dangerous without it.
If snow or ice was previously treated with a deicing product, try to avoid piling it on the root zone of just one nearby tree or shrub. Spreading the treated snow around reduces the likelihood of toxicity building up in one area. Also, try to avoid piling treated snow or ice on long-lived trees. Turfgrass can be killed when large amounts of salt-laden snow are piled on it over the course of winter.
Another option for controlling ice with minimal negative impact on the environment is to use an anti-icing product, which is generally applied as a liquid using a sprayer right before a storm. As the snow falls, the bottom half-inch or so will turn into slush that can be removed, which prevents ice from forming that would require a de-icer. The Garden currently uses sand on roads and walks to control slippery conditions once the snow is removed, with deicing products used minimally in certain areas. The sand improves traction on slippery surfaces and it’s environmentally benign. Try mixing some deicing product in with sand to minimize the amount of ice melt used at home while keeping walks safe.
All ice melt products pose some kind of risk to your pets by irritating paws and causing gastrointestinal upset if it’s ingested. Repeated exposure can cause chemical burns on paws. Most common ice melt products contain sodium chloride, potassium chloride, calcium chloride or magnesium chloride, which are all toxic to dogs if ingested. Pet-friendly ice melts typically contain urea or magnesium chloride, which are considered safer but still might cause gastrointestinal upset while being less effective at melting ice. Ethylene glycol-based ice melts contain the same active ingredient as antifreeze, which is deadly to pets if ingested. Products with urea as the main ingredient are considered some of the safest options for pets. Keep yourself — and your pets — safe out there.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.
