• Calcium chloride. The traditional ice melt. Pros: It melts ice to about minus 25. It probably won’t hurt plants unless you use too much. Cons: It turns concrete and other hard surfaces slippery and slimy.
• Rock salt (sodium chloride). Pros: It’s the cheapest, effective to about 12 degrees. Cons: It can damage soil, plants and metals.
• Urea (carbonyl diamide). This is a fertilizer that is sometimes used to melt ice, effective to 21 degrees. Cons: It is only about 10 percent as corrosive as sodium chloride, but it can contaminate ground and surface water with nitrates.
• Calcium magnesium acetate. This is a newer product that is made from dolomitic limestone and acetic acid. Pros: Unlike other products, it does not form a brine but instead helps prevent snow particles from sticking to each other or the surface. It has little effect on plant growth or concrete surfaces. Its effectiveness decreases below 20 degrees.
“Limited use of any of these products should cause little injury,” Upham writes in K-State’s Horticulture newsletter. “Problems accumulate when they are used excessively and there is not adequate rainfall to wash or leach the material from the area.
“Since limited use is recommended, it is best to remove the ice and snow by hand when possible. When (ice melters) are applied, practice moderation.”