How to Protect Your Landscape from Salt Damage

Every winter, southern New Englanders apply tons of ice melting materials to sidewalks, driveways and steps.  These chemical deicers will remove ice but they can damage the environment if not used carefully.

Most de-icing chemicals are technically "salts" that work by lowering the freezing point of water below 32 degrees. There are a number of different products that have different minimum working temperatures and speed of action. Most of the products cause wear and tear on concrete and metal surfaces.  Also, in our gardens, these salts can damage plants in two ways:

·        Direct contact with the salts or with salt spray can lead to bud death or twig dieback.  For example, it is common to see brown branches on evergreens along highway usually showing up in February or March. Also, grass along driveways may die or the growth may be stunted from salt.

·         Repeated application of salts over years can result in a build-up of salts in the soil. This will damage plant roots and ultimately may kill grass and other plants.

Here are some tips to prevent garden problems from use of deicing salts around your home.

• Avoid using traditional road salt (sodium chloride). It is the most harmful to plants and also has the highest potential to contaminate waterways (it is very soluble).

• Always use a deicer product after you have shoveled and swept – don’t try to use it to melt the snow and ice – shovel or sweep away as much as possible, then put the deicer down – in a very thin layer.

• Applying deicer after shoveling will also protect your plants by keeping you from shoveling snow that contains deicers directly on to the plants.

• When you can, substitute an abrasive material such as sand or kitty litter for salt. This can be messy (when tracked into the house) but the sand or kitty litter won’t harm your plants and will provide good traction on ice.

• If you need a little more melting power, try mixing the deicing salt with sand or kitty litter so that you can reduce the amount of salt used. This will melt the ice and provide traction.

Salt spray from the roadways also can damage roadside plantings. If you are planning a new landscape:

• Keep plants as far back from the road as possible.
• Plant salt tolerant species next to roads or driveways and walkways that are likely to be treated with salt. For example, white oaks and white ash trees can tolerate more salt spray than white pines and hemlocks.
•  A list of salt tolerant plants can be obtained by calling the URI CE Gardening Hotline at 1-800-448-1011.

If you live near a busy road or highway that will be treated with salt, mechanical barriers can provide protection:

·        Put up a snow fence to protect low-growing shrubs and small trees.

·        Or use burlap to protect your plants from damage.