Rock Salt and Ice Melter

November 22, 2015

Rock Salt and Ice Melter – No Kidding! 

Roxbury Farm and Garden is an old feed store since 1929 that has transcended into a well stocked a garden center, but is still in the feed business.  Part of the feed business includes stocking salt for livestock.  Naturally if you stock salt to feed livestock you may as well sell it for water softeners and ice melting as well.  Indeed Roxbury is a great place to shop for all of  these salt needs.



In general salts need to go into a liquid form called “brine”.  The brine will lower the freezing point thus melting a light coating of snow or ice.  Once the brine becomes more diluted from additional snowfall the melting is likely to become less effective.  Traffic will also disburse the melting compound.

IF YOU HAVE A COUPLE OF INCHES OF ICE THE USE SAND FOR TRACTION.  Melting compounds can’t be expected to melt through thick ice.  In the Rockies I’m told that chemicals are rarely used.  Gravel for traction is the preferred choice and the business to be in is windshield replacement.

Follow the directions on the bag.  Overuse of salt is wasteful and does the most damage to concrete and plants.  Pre-treatment is strongly recommend for walkways and low traffic areas.  For high traffic areas delay application until precipitation begins so the traffic doesn’t knock the salt off of the road into the ditches.

Ice melter bag                                                                          Brrrr!


Rock Salt (NaCl, sodium chloride, the stuff you cook with, etc.) melts to a temperature of about 28 degrees Fahrenheit.  Heavier applications can sometime thaw to lower temperatures.  Once the temperature reaches 15 degrees Fahrenheit the rock salt is not effective.  Higher dosages equate to more salt damage.  Generally application rates are 60 pounds per 1,000 square feet, or 8 ounces per square yard.

If you apply rock salt when the temperature is dropping significantly you could have a thaw following by a re-freeze.  On an interstate highway this could be an absolute disaster.

Additionally NaCl is very corrosive to many things including concrete and metal.  Concrete, especially younger concrete in terms of years, will “scale” or disintegrate from a heavy assault of salting.  NaCl also “burns” plants by dehydrating roots and soft tissue.   Avoid application on plants and grass. Rock salt is generally mined domestically.

Magnesium Chloride melts to much lower temperatures than NaCl and is less corrosive than many other salts.  This is the preferred salt for bricks and concrete.  MAG is more plant friendly, but again avoid application on plants and grass. MAG costs more than rock salt.  Our MAG comes primarily from the Dead Sea.  MAG can be slippery if the temperature is mild. Generally application rates are 30 pounds per 1,000 square feet, or 4 ounces per square yard.  So far there is a MAG shortage this winter.

Thanks, Andy Lynn – Roxbury Farm & Garden Center

p.s. – We don’t sell hot chocolate, but we have plenty of snow shovels, bird feed and bird feeders.  Stop by for a cup of the worst coffee in town.  It’s free.