Well, the predicted Armageddon blizzard fiddled out for most of our area, although up north, in some places in Saratoga County, they did get 24 inches or so of snow. In the Catskills, Hudson Valley region, the snow totals were more like 5 to 9 inches due to a mixture of rain and and sleet. The weather forecasters did get the temperatures correct however and one day last weekend, Albany NY was the coldest city in the entire US! One inch of ice is more hazardous than one foot of snow when it comes to driving or trying to walk out to the mailbox. Consequently lots of people will be buying rock salt or other deicing materials.
As much as we need to use it, it is a fact that rock salt (Sodium chloride) takes a heavy toll on road structure. It destroys concrete and creates tiny cracks in black top pavement. We will pay the price for this later on in the spring. Pot holes form when water gets into those tiny cracks in the road as the freezing process creates forces that can easily break asphalt or even concrete. Water is the only substance that expands as it freezes. Just about everything else shrinks! The cracks grow into pot holes with every freeze and thaw. Of course, down here in Florida we don’t get pot holes, we get sink holes that sometimes swallow houses overnight!
It is not uncommon in the Capital District/Hudson Valley for heavily traveled roads, such as the Thruway, to receive 40 to 80 tons of deicing salt per lane mile per year. That works out to about 15 to 30 pounds per linear foot. It is surprising that any roadside plants can tolerate that much salt, but most do. If they received a fraction of this much salt during the growing season, the roadsides would be devoid of vegetation. There is little the homeowner can do to change the road salt situation but there are some alternatives to salt that may be used in the home environment.
Road salt or deicing salt is mostly unrefined rock salt, containing about 98.5% sodium chloride. Calcium chloride is sometimes used when temperatures are extremely low, but it is about eight times as expensive as sodium chloride. Rock salt is pretty useless at temperatures below +10. Rock salt causes injury to plants by absorbing water that would normally be available to the roots. Even when moisture is plentiful excess salt can create a drought like environment. In addition, when salt is dissolved in water it breaks down into sodium and chloride ions. Roots readily absorb chloride ions and then they are carried through the sap stream to actively growing portions of the plant such as leaf margins and shoot tips. Calcium chloride is not nearly as damaging.
Plants most likely to be affected in the home landscape are those that receive lots of salt laden snow. For example, if you routinely apply salt to your porch or steps or deck, the plants growing nearby are most at risk, especially if you shovel snow on top of their root systems. Likewise, plants along your driveway or roadside are more at risk than those in the backyard. So what are the alternatives?
First, buy calcium chloride instead of rock salt, or purchase one of the newer deicing materials that are reported to be even less toxic to plants, such as CMA (calcium magnesium acetate). This stuff is very expensive, about 30 times as much as common rock salt, but it is the most environmentally friendly. In a pinch ordinary chemical garden fertilizer such as 5-10-5 will also melt ice, but if it gets anywhere grass is growing, like along your driveway, the grass will grow at an astonishing rate! I used urea once, which is about 46% nitrogen and for years I had to mow the nearby grass twice as often as the rest of the lawn.
These new products are quite expensive but so are replacement plants! If you just want to improve traction try using sand or kitty litter or even fine gravel. Keep in mind however that you will most likely be tracking these materials into the house along with the snow on your boots. Never use soiled kitty litter for this reason! Wood ashes have also been used for traction, but too much wood ash spread over your plants can raise the soil pH to damaging levels. Wood ash will also be carried in the house with the snow on your boots and it leaves an unsightly gray residue.