Deicing Salts Can Damage Plants by Carol King

Use care when applying deicers

Winter is in full swing along the Front Range and with it comes the inevitable snow and ice causing slippery roads, sidewalks and driveways. Most municipalities use mag chloride on roadways.  Homeowners and business people also often use rock salt (sodium chloride, or table salt) or ice melt on slippery walkways. All of these are salts, and salt works by lowering the melting or freezing point of water. The effect is termed 'freezing point depression'. 

While salt is a necessary part of winter road and walkway safety, it does have its drawbacks. Unfortunately for your plants, it often winds up in the landscape causing injury. When salt sprays from puddles onto plants as cars drive by, it may scorch leaves or kill buds and twig tips. Pines in general are especially noted for their sensitivity to roadside deicing salts. If you notice dying vegetation is on the side of plants facing the road or driveway, the damage has likely been caused by salt spray. Turf grass and other plantings can also be killed if salt-laden snow is piled on it over the course of winter. Accumulation of salt in the soil makes it difficult for plant roots to absorb water and will inhibit seed germination of grasses and wildflowers.

Here are a few tips to minimize salt damage to plants:

1. Don’t use deicing salts adjacent to sensitive plants.
2. Shovel early and often. Scrape away as much snow and ice as possible to minimize the need to use salt.
3. If you must use salt, mix it with sand to reduce the amount needed. You only need about a handful of rock salt per square yard treated.
4. Don’t shovel salt-laden snow and ice onto plants or turf grass.
5. Construct temporary barriers using plastic, burlap, or snow fencing to keep snow piles off plants.
6. Wrap newly planted conifers with burlap to protect them from salt spray.
7. Apply no more than the recommended amounts to minimize negative impacts on garden plants and on concrete and other surfaces.
8. Use sand alone or consider using an alternative deicer, such as calcium magnesium acetate.
9. If plants have been exposed to excess salts, wash off the foliage, and irrigate thawed soils to help move the salts out of the root zone.
10. Water plants every three weeks during winter if precipitation has not fallen, to help avoid plant stress.

Proper use of deicing products will not only protect you from falls, it will protect your landscape from unnecessary salt buildup.