Blackwelder: Rock salt damages plants

Published 12:00 am Friday, January 7, 2011

With more ice and snow predicted over the next few days, sidewalks, driveways and entryways may be extremely treacherous with ice and snow.
Many people will apply rock salt to quickly melt the ice and snow on sidewalks and drives.
There are now products on the market used for rapid ice melt that will not damage plants, but some people still use rock salt. Rock salt should be applied sparingly, avoiding placement near valuable landscape materials to avoid salt run-off, which damages plant material.
Rock salt works well but can damage landscape plant materials and can also be a runoff pollutant that may damage our streams. Normally, two or more light salt applications are no cause for concern.
Snow, ice and normal rainfall usually leach salt through the soil, preventing plant damage. In colder northern climates, which often require routine salting, it causes extensive damage to turf and shrubs.
Salt damage to landscape plants is similar to over-fertilization. Leaf margins and tips easily burn, with eventual defoliation. Extreme damage shows itself quickly, in a matter of days, whereas slight salt damage may not manifest itself until spring or early summer.
Try to keep salt and other de-icing granules as far away from trees and shrubs as possible when applying to entranceways, sidewalks or roads. Be sure to read and follow the instructions and apply only as needed. Those who apply salt on a routine basis should plan to leach shrubs with water during the spring.
Salt damage can be avoided by using rock salt substitutes. These de-icers effectively melt ice and are safe on the plants and the environment. Ice melting substitutes are available in both granular and liquid formulations for easy application.
Sand is also an effective salt-substitute. Actually, sand does not melt ice or hard packed snow, but does provide good traction to prevent slipping. It’s messy and somewhat unattractive, but sand stays on the surface of the ice through its duration and is easily swept off when sidewalks dry. It is the safest way to protect tender shrubs or trees.
Darrell Blackwelder is the County Extension director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County. Learn more about Extension events and activities on Facebook or at