Which is better to use on icy walkways, sand or salt? The answer is both. Sand and salt serve two separate functions. Sand creates traction while salt raises the melting point of ice. Both of these options are fairly inexpensive and abundantly available. However, sand and salt can be very damaging on a residential landscape if used in excess. For homeowners with boulevard gardens or permeable pavement, sand and salt may cause more damage than good.
What effect does salt have on plants? Excess amounts of salt on plants can be severely damaging to the growth and overall health. Protect plants in winter. When the ice or snow melts in spring time, all of the salt drains into the soil and absorbed into the plant. Plants and grass near walkways, driveways, and streets are especially susceptible. The plant’s growth can be stunted, withered leaves, and in extreme cases you may find completely dead plants.
For those living in cold climates such as Minnesota, de-icing is a necessity, almost a way of life. Boulevard gardens and lawns are extremely susceptible to salt damage to plants from constant snow dumping. All hope is not lost for those poor plants though. Here is a list of plants that are rated Tolerant or Moderately Tolerant to the negative effects of salt:
- Coral Bells
- Day Lilly
- White Fir
- Horse Chestnut
- Colorado Blue Spruce
The main product used for de-icing salt is Sodium Chloride (Rock Salt). This is the least expensive product and can be found at gas stations and hardware stores. However, there are other products that have less of an impact on plants. Calcium Chloride is less corrosive and less damaging to plants, but is slightly more expensive than Rock Salt. Calcium Chloride is more effective in colder temperatures too.
Unlike salt, sand will not dissolve into the water and melt away. Instead, large deposits of sand will be left on the edges of streets and driveways. This is a minor inconvenience in most cases, but can sometimes cause drainage issues if there is a low spot receiving lots of runoff. Sand on permeable pavement however will cause a much larger problem.
Permeable pavement is designed in a way that allows water to flow through joints and permeate into the soil. It is becoming more and more common to use a permeable paver design on walkways and driveways. If sand is spread across a permeable driveway, it will fall through paver joints and eventually clog the whole system up. Water will no longer drain properly and the permeable pavement won’t serve much of a function anymore. In other words, DON’T USE SAND on permeable pavement! There are some maintenance tricks to fix clogging, but is easier to just avoid it in the first place.
Using salt and sand on icy walkways is a no brainer, but it may cause more winter damage than good by the time spring rolls around. Avoiding sand and salt in a landscape design will extend the life of surfaces and plants. Instead use salt tolerant plants and salt alternatives in those high risk areas of the yard.