The first few days of Thanksgiving week we had rain in Lincoln and then temperatures started to fall so on Saturday morning the streets and sidewalks were a sheet of ice. By noon it had started to melt and the streets were not too bad. If this weather of moisture and then freezing temperatures continue like this, the month of December will be one to remember.  

          With the ice, I saw a lot of de-icing products being put on the sidewalks and driveways. Make sure you select the right product to melt the ice and follow the label directions in order to make the walkways safe and avoid plant injury.

           The four most common products are:

1. “Sodium chloride (NaCl).” This chemical, commonly referred to as rock salt, is the most prevalent deicing chemical, and in general, has the lowest price tag of all deicers. An estimated 10 to 14 million tons will be used yearly on roads in the United States and Canada. The practical working temperature of the product ranges between 15 degrees F. and 20 degrees F. NaCl is not recommended as it is hard on concrete driveways and sidewalks and when it mixes with melted snow or rain can run off and burn your grass. It really shows up along the edge of the driveway and the walk.

2. “Magnesium chloride (MgCl).” MgCl is usually sold in a 30 percent concentration with an associated freeze point of 3 degrees F.

3. “Calcium chloride (CaCl).” Available in flakes, pellets or liquid, CaCl produces an exothermic reaction, giving off heat. Because of this, it often performs better than many other deicing salts, especially at lower temperatures. Some highway departments spray liquid CaCl over rock salt to lower its melting temperature. The practical melting temperature is typically considered to be approximately minus 10 degrees F.

4. “Potassium chloride (KCl).” KCl is similar to or equivalent to potassium based fertilizer products. It is often promoted as beneficial to plants. The product as a deicer doesn’t work unless temperatures are more than 25 degrees F. As a stand along product it is relatively expensive and more often is seen as part of a deicer blend. (1)

          A NebGuide from the University also includes other products but says that urea, ammonium sulfate, and other Nitrogen salts are rarely used as deicers because of the potential for nitrogen runoff and leaching into water sources. In many areas nitrogen salts are not approved for deicing because of these environmental concerns. This NebGuide also has a list of trees and shrubs and their tolerance for salt in the soil. (2)

          Abrasives such as sand, cinders, and ash have relatively few impacts on the environment or plants. However, these materials do not melt ice but do improve traction on slippery surfaces. The disadvantage of these materials is that they can track into the house and accumulate in the landscape, and may require removal after the de-icing season.

          Regardless of what product you use, be sure and check the label for what products are in the bag, how much of each, how to apply, and how often it can be applied.

Copyright 2015


(1) Hort News, Iowa State University Extension publication, HortNews, November 8, 2002 issue, and pages 126-127. (

(2) A list of plants with their salt tolerance is available in UNL Extension’s NebGuide #1121-Winter Deicing Agents for the Homeowner.