Salt does more than melt the ice on your sidewalks and driveways. It can harm your lawn and shrubs, says University of Missouri Extension turf management specialist Brad Fresenburg.
Too much salt can leave dead strips along sidewalks and driveways. It can kill shrubs and flowers.
Before you throw salt on icy walkways, know the type and amount of salt to use. Avoid products like rock salt that contain sodium. Melting substances that contain magnesium chloride or potassium chloride are a better choice, Fresenburg says.
Use a small amount and give the product time to break down the snow and ice crystals. A little goes a long way, he says.
You will know that you have used too much if pellets or salty residue remains after the ice has melted.
Some products cause sidewalks to pit and crumble. Instead of salt pellets, use sand or cat litter as grit for traction.
Improper use of de-icing materials damages plants in the same way too much fertilizer salt can, Fresenburg says. Plants absorb needed minerals from the soil as salts in soil water. Extra salts increase the energy with which water is held in the soil. This makes it harder for plants to extract soil water and stresses the roots. If salt levels get too high, roots burn and leaves scorch.
Direct contact of salt with evergreens, such as junipers, causes foliage to brown and die back. Another problem associated with some types of ice melters is degradation of soil structure. Accumulation of sodium causes clay particles to pack together more densely, leading to poor water infiltration and internal drainage.
For more information, see “Consider Nearby Plants When Using Sidewalk Ice Melters” (Missouri Environment & Garden, January 2011) at ipm.missouri.edu/MEG/?ID=61.